# The dsl joey mod thread



## TwinACStacks

Well Gang, because I'm getting weary of emptying my inbox with questions concerning the DSL INFO thread, LOL, I've decided to post the "meat and potatoes" of the Mods for the DSL series without the additional Banter between contributors. Joey Voltage was kind enough to provide some open-source mods which form the basis for the alterations, Along with input from the rest of the resident BRAIN TRUST: JON, JCMJMP and the MAJOR. My Humblest appreciation and Thanx to all of You. These Guys are GREAT to have on your side folks....

Me? I'm an electrician but in NO WAY am I an AMP TECH!! I'm just dangerous enough to try it all. I've owned 5 DSLs in a Love-Hate relationship with the Red and Green Channels. (Actually I'm beginning to believe that this is really a SINGLE CHANNEL AMP with 4 Distinct MODES!!!) THIS time around I decided to call upon the experts to help make it True Love, and we all know True love is hard to find...


FIRST: (AFTER DISCHARGING THE LETHAL VOLTAGES IN YOUR CHASSIS!!!) Determine which version of Boards that Your DSL contains Using this link:
Marshall DSL

There are about 5 different Version (issue) boards used. The mods are centered around the Front Board (Pre) and Tubeboard (Main) and are based on THESE TWO VERSIONS, if yours don't match up you have a different version:

JCM2 60-02 iss5 (Tube) AND JCM2 61-00 iss1 (Front)


Front Board: 

NOTE: THESE MODS AFFECT THE RED LEAD 2 MODE ONLY (removing C12 will also darken Lead 1)

1M Resistor from Wiper to Ground on Vr3 ****
C12 Lower to 150pf or REMOVE (I removed it)
C10 replace with .0022 uf
R20 Remove and *JUMPER*

**** These can be bridged on the other side of the Board. Find the 4 Pins that are the Actual Pot terminals, (Not the Two Board mounting pins), follow the Traces. The inner one that has R19 on it is the WIPER, the outside one that connects to Con 5 pin 2 is the Ground. ( Using your meter set to continuity works well here) Solder your 1M across these 2 pins leaving the legs long, then bend flat to board using a piece of electrical tape attached to the board to insulate the leads from accidentally shorting out to any other exposed solder connections. Electrical splicing tape works quite well here as it adheres to the board better than vinyl electric tape.


Mainboard: 

NOTE: THESE MODS AFFECT ALL CHANNELS/MODES

C9 replace with 1000pf (.001uf) 500V
C12 replace with 1uf 63V

Here is a Link for the Caps:

MKS2-1/63/5T WIMA Polyester Film Capacitors


Now if You find that the overall texture of the amp is, or has become too dark:

Mainboard:

Replace R30 (470k)with 68k to 220k resistor this will Decrease the Fizziness and the OVERALL GAIN as well and also brighten the Amp. I personally Piggybacked, (using a pair of test leads), a range of resistors across the Legs of R30 from 82k to 1M and decided I liked 1M the Best. This brought the Value of R30 to 320k. I then soldered it in place across the legs of R30. This way it is easily changed if I decide on a different value without pulling the PIA Mainboard!!! This particular Mod is pretty much season to taste. One of the Techs or Myself can figure out what value you need for "Piggybacking", or you can try and figure it out yourself:

R1XR2 Divided By R1+R2= the Total resistance of Both Resistors combined. Use the Value of R30 (470)k for R1 and the resistor You want to try as the value for R2. (Try: 82k, 120k, 220k, 330k, 470k and 1m)

Also if You find that the Green CRUNCH Mode is too boomy especially with the deep switch engaged:

Frontboard:

C8 replace with .001uf to .0022uf (I used .0015uf)

Here's a link: http://www.mouser.com/ProductDetail...EpiMZZMsh%2b1woXyUXjyBw8LYChpgf%2bpPFAhHPmAM=


THESE ARE THE EXTENT OF THE ORIGINAL MODS. 


Now THIS is the "while You are in there" section of the Mods that SHOULD be performed.

C46 if You have one. This is an underspeced Cap that apparently is to prevent parasitic oscillations. It can short out and Take out the board it's on, as well as your OT. Either CUT it OUT or replace it with a +1000V version of the same value (22pf). I say "apparently" because I have heard nothing about anyone experiencing oscillations after removing this cap completely.

Change out the Grid Blockers on the Mainboard. Most versions have 220K in place, replace with a more normal "Marshall" value 5k6 resistor. I'm of the understanding Alan Bradley Carbon Comps are suited quite well for this, I used regular +/- 5% carbon films from Radio Shack that I had on hand.

The locations for these are: R7, R10, R66, R70

Also because of frequent run-away biasing problems That appear to be temperature related, Upgrade the Bias resistors. I suggest a more temperature-stable precision metal film 1/4 to 1W, PRP or Vishay Dale.
Here is a link for the PRPs: Sonic Craft High-End DIY Audio Parts

The locations and Values of the Bias resistors are: on the Mainboard
R68 33K
R77 10K
R67 220K
R69 220K

One last preventive measure, On the rear of the chassis the speaker output jacks should have separate grounds installed. the 4&8 ohm jacks are grounded through the 16 ohm jack, (which Bypasses via an open/close contact), the 4&8 Ohm jacks when the 16 Ohm is used. Sometimes this contact doesn't close because of Dirt etc. so when You are plugged into the 4, 8, or Both, the Amp is actually seeing No load at all and: Bye-Bye OT and Maybe more. If You use only the 16 Ohm jack this is not a concern. This can be accomplished by soldering a short piece of wire to the shoulder of W6 Ground connection and to one of the metal bands on either the 4 or 8 ohm jack that is closest to the inside rear surface of the Chassis. When this is done however there will be no auto disconnect. ALL 3 jacks will be active ALL the time. Please DO NOT try and run 3 Cabs at the same time!!!

Now for the FUN Stuff:

Replace the OT and Add a Choke.

Add a 3H Choke at the R71 Resistor (270R 7Watt) on the Mainboard. Remove R71 and connect the two wires for the choke in its place. You can mount it behind the power Trans at the Rear of the Chassis. You will need to swing the Powerboard out of the way for drilling. TIP: Because this resistor is mounted with a LOT of solder, (and I was a little afraid of overheating and lifting the traces), I simply snipped the body off the Legs and soldered my wires directly to the leg remnants. Very un-professional and very effective.

A MAJOR sound Modification is the replacement of the puny Stock Dagnall OT. JCMJMP has drop in replacements on: Marshall DSL
Also they are available from Mercury Magnetics, I believe Jon deals in these. Because I had a deal fall into my lap, I used a replacement for a 100 Watt Plexi: a Dagnall C1998 or the Later version C2668. These you can find on Ebay or VERY good Clones from Marstrans or Metro Amp.

For those of You electing to go this route, Here are the Wiring Directions For the 100 Watt Dagnall C1998/2668 Plexi Stand-up mount OT.(also the Marstran and Metro Clones)

NOTE: THIS TRANSFORMER IS FOR THE 100 WATT DSL. FOR 50 WATT use a 784-139 Plexi CLONE.

Dagnall Plexi Primaries/ Stock DSL Dagnall
RED.............................................White (goes to V5,V6)
White.......................................... Blue CT
Brown.......................................... Purple (goes to V7, V8)


Dagnall Plexi Secondaries/ Stock DSL Dagnall
16 Ohm Green................................Red
8 Ohm Yellow.................................Orange
4 Ohm Black.................................. Green
Comm. Brown................................ Black

For the 50watt 784-139 Clone:

784-139 Primaries/ Stock DSL Dagnall
RED.............................................White (V4)
Brown..........................................BLUE CT
White..........................................Purple (V5)

784/139 Secondaries/ Stock DSL Dagnall
16 Ohm Gray.........................................RED
8 Ohm Green.........................................Orange
4 Ohm Yellow........................................Green
COMM. Orange......................................Black

If desired you can also change out the Power Xformer, although there is much less impact on the sound. They are also available as drop-ins from JCMJMP or Mercuries from Jon. I don't believe there are vintage-type repros available with the low voltage power taps needed for the DSL channel switching at this time.

You can use some quick connects, I wanted to be neater and installed Molex.

Lastly, SEEK OUT SOME GOOD NOS TUBES: MartyStrat54 is THE hookup for this.

For those who need/want to KNOW what these mods DO, (courtesy of Joey):

on the pot board:

put a 1M resistor from the wiper to ground of Vr3: This has a dual function. It limits the amount of drive signal possible for low frequencies below 169hz (not taking in account for any other low frequency roll off's below this point of course). full up, frequencies below this point will be down -6db, and flat. it also slightly alters the peak response of the shelving filter created by R19,C11, and Vr3.

keep C12 or remove: Keeping C12 alters the R19,C11,Vr3 shelving filter further by moving the beginning of the upward shelf high at lower gain settings (because the top half of Vr3, anc C12 are now in series with R19/C11 ignoring other circuit impedences of course) giving an edgier sound. when about 3/4 of the way up the shelving effect becomes negligable, and eventually the cap is shorted out by Vr3. Removing it obviously will darken the tone of OD1, and OD2 by removing this effect, but also does so because this now puts larger resistance in series with the grid of the next valve, whose input capacitances will creat a lowpass filter with this resistance, and bleed highs further.

replace C10 with a .0022uf: Reduces the amount of low frequencies passed on to the next stage in conjunction with R19, Vr3, and the source impedence of the driving stage. this has the bennifit of tightening the sound by somewhat tailoring the bass content within the guitars useable range, and can encourage a higher mix of second order harmonic content (but thats for another discussion). this will also help with potential blocking.

jumper R20: adjusts the strenght of the afformentiond shelving filter.

on the tube board:

C9 1000pf (.001uf)creats a single pole high pass roll off of around 3.2Khz which is around the fundamental of highest note of the guitar. there are also very few useful harmonics for guitar above this, or that can really be reporduced by most guitar speakers. it also can reduce hiss, as well as rolls off the glassy harmonics of the 220K plate load.

C12 1Uf provides a more useable mid shelving for overdriven guitar while retaining some current induced feedback for low frequencies. also sounds good for the clean mode as well

Joey Voltage 

BE CAREFUL!!!!!! The voltages inside these amps can KILL YOU....DEAD. If You are unsure about what You are doing ASK!!! Or take/send your Unit to a qualified Tech, any of the Techs behind this thread are outstanding!!! 

Hope You Guys and Ladies, enjoyed the JOEY MODS THREAD, and good luck with your quests for good tone with the MOST AWESOME MARSHALL HEAD EVER...

Here are some additional links for Parts:

http://metroamp.com/
http://marstran.com/
http://www.mouser.com/Home.aspx
http://tubesandmore.com/

TWIN


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## jcmjmp

The mods listed by TwinAC above pretty much covers everything but these are more mods that I've been asked for on a regular basis.

1) Footswitchable channel modes:
http://www.marshallforum.com/workbench/8904-marshall-dsl-50-100-clean-crunch-footswitch-last.html
2) Deep switch
3) Mid cut


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## 6StringMoFo

I'd be interested in Transformers and the upgrades for the 2 channels to clean and balance them out.

Voodoo has some nice mods for them, anyone know what mods their doing to them?


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## Joey Voltage

jcmjmp said:


> The mods listed by TwinAC above pretty much covers everything but these are more mods that I've been asked for on a regular basis.
> 
> 1) Footswitchable channel modes:
> http://www.marshallforum.com/workbench/8904-marshall-dsl-50-100-clean-crunch-footswitch-last.html
> 2) Deep switch
> 3) Mid cut



2, and 3 are easy to deal with. we have already discussed the deep switch. Stock, in conjunction with C29, the opamp creates a bandcut filter with a resonant frequency in the 50hz region which appears as a boost when the feedback is returned. you can shift the resonant frequency up by adjusting the value of C29. a good place to start is 1uf - 2.2uf, and the cap makes a difference on how wide the Q of the filter is. If you want a wider Q, stick with tantalum or electrolytic. If you want a slightly more precise Q, go with film.

with three, there are many ways to go about this, and I think the easiest is just to play around with the tonestack a little, and exploit the circuitry that is already there for the "shift" function.


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## jcmjmp

Joey Voltage said:


> 2, and 3 are easy to deal with. we have already discussed the deep switch. Stock, in conjunction with C29, the opamp creates a bandcut filter with a resonant frequency in the 50hz region which appears as a boost when the feedback is returned. you can shift the resonant frequency up by adjusting the value of C29. a good place to start is 1uf - 2.2uf, and the cap makes a difference on how wide the Q of the filter is. If you want a wider Q, stick with tantalum or electrolytic. If you want a slightly more precise Q, go with film.
> 
> with three, there are many ways to go about this, and I think the easiest is just to play around with the tonestack a little, and exploit the circuitry that is already there for the "shift" function.



Yup! 
2) You can also play around with C28 for the upper frequency cutoff, although the effect will not be as drastic as changing C29.
3) If there's any demand of the mid cut button, I can post some simple mods for those. The basic devices that are involved are C19, R36 & C22. Depending on what you're after, you can change these devices to get to where you want with the mid cut.


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## jcmjmp

6StringMoFo said:


> I'd be interested in Transformers and the upgrades for the 2 channels to clean and balance them out.
> 
> Voodoo has some nice mods for them, anyone know what mods their doing to them?



The Voodoo Mods are probably very similar (in essence) to the mods listed above.


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## 6StringMoFo

If someone wants to make a few bucks, put together a few kits with (recommendations) on Choke and Transformers


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## Joey Voltage

6StringMoFo said:


> If someone wants to make a few bucks, put together a few kits with (recommendations) on Choke and Transformers



Well, I guess the Idea is to give more control to the user because that is who is playing through the amp inevitably, not any of us!, and not all of these mods are going to work for everybody. It's more of a resource than a money maker


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## thrawn86

Twin, you've been Stickied!! Congrats!


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## Buggs.Crosby

3 stickies in the sites history of this section...2 this year?....strange days indeed


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## LPMarshall hack

What is a sticky?


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## Landshark

Joey Voltage said:


> 2, and 3 are easy to deal with. we have already discussed the deep switch. Stock, in conjunction with C29, the opamp creates a bandcut filter with a resonant frequency in the 50hz region which appears as a boost when the feedback is returned. you can shift the resonant frequency up by adjusting the value of C29. a good place to start is 1uf - 2.2uf, and the cap makes a difference on how wide the Q of the filter is. If you want a wider Q, stick with tantalum or electrolytic. If you want a slightly more precise Q, go with film.
> 
> with three, there are many ways to go about this, and I think the easiest is just to play around with the tonestack a little, and exploit the circuitry that is already there for the "shift" function.





jcmjmp said:


> Yup!
> 2) You can also play around with C28 for the upper frequency cutoff, although the effect will not be as drastic as changing C29.
> 3) If there's any demand of the mid cut button, I can post some simple mods for those. The basic devices that are involved are C19, R36 & C22. Depending on what you're after, you can change these devices to get to where you want with the mid cut.



Now here's a good one... It says tone shift on the front plate... Is there a value to produce a "mid boost" rather then a cut?


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## Buggs.Crosby

LPMarshall hack said:


> What is a sticky?



Permanent thread...it will always be at the top of the page also


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## Joey Voltage

Landshark said:


> Now here's a good one... It says tone shift on the front plate... Is there a value to produce a "mid boost" rather then a cut?



yep


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## jcmjmp

Landshark said:


> Now here's a good one... It says tone shift on the front plate... Is there a value to produce a "mid boost" rather then a cut?



I'll post a "mid boost" mod when I get a chance to look and analyze that part of the circuit.


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## LPMarshall hack

Buggs.Crosby said:


> Permanent thread...it will always be at the top of the page also





Aahh...ok, tks.


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## Joey Voltage

jcmjmp said:


> I'll post a "mid boost" mod when I get a chance to look and analyze that part of the circuit.



It's easy, and there are many differen't ways you can do it. The most popular method is to increase the value of the treble cap, but you want to becareful because you can make other controls ineffective. Like wise if you want to give your self a "cloth baggy" Iron maiden type mid range, you put a .001uf cap from wiper to ground of the mid pot, this will shunt some upper mid frequencies when the pot is increased. If you want to make the midband less lossy, you can increase the value of the mid pot.

There's tons of other crap you can do, and if you don't use the deep switch you can even increase C29 to the point where you are moving the resonance frequency up in the 750hz-1K range. you can also add many different interstage networks and loops.


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## jcmjmp

Mid Shift Boost MOD

Joey suggested some good ideas, especially about using the deep button as the mid boost.

My take on this, is different. To get a bit of a boost with the mid cut button, I would change R36 to 33K and run a wire to make it run in *parrallel* with R35. In conjunction with this, you can try lowering C21 a little, to like 18n to re-adjust the bass from the R36 change. I would also experiment with C19 to also run it in *parrallel* with C20 to get more mid band in BUT increasing the value of this cap will move the mids lower, which may not be what you want to do. Adjust to taste. 

If you want more mids but still be able to get good range with the Mid Shift button out, replacing the 22k mid pot with a 100k pot is a good idea. You'll have more range and more mids with the control cranked.


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## TwinACStacks

JC that 100K mid pot sounds interesting. Will it give appreciably more Range? Will the Korg Pots (11mm) from AES fit. Exactly what type/manufacturer are on the DSL anyways? Vr3 has 4 Pins, that much I know...

 TWIN


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## Joey Voltage

TwinACStacks said:


> JC that 100K mid pot sounds interesting. Will it give appreciably more Range? Will the Korg Pots (11mm) from AES fit. Exactly what type/manufacturer are on the DSL anyways? Vr3 has 4 Pins, that much I know...
> 
> TWIN



I would go for 50KL, If you go too high, it will make the other controls not as effective, as there would be minimal loading. Although you have to keep in mind alot of the analysis of tonestacks really only applies to small signal theory.


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## jcmjmp

TwinACStacks said:


> JC that 100K mid pot sounds interesting. Will it give appreciably more Range? Will the Korg Pots (11mm) from AES fit. Exactly what type/manufacturer are on the DSL anyways? Vr3 has 4 Pins, that much I know...
> 
> TWIN



Joey's 50KL is also a good value. My DSL uses Alpha pots. You should be able to get them from mouser or digikey.


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## een7gdr

jcmjmp said:


> Joey's 50KL is also a good value. My DSL uses Alpha pots. You should be able to get them from mouser or digikey.



I have been ordering parts from Marshall, as i have a trade number with them, for the seperate crunch volume control and it appears as if the DSL have and still use the Alpha pots. The markings and colour have changed slightly over the years (with RoHS changes etc) but they inform me they are still from the original manufacturer so they should be readily available from the likes of mouser or digikey.


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## TwinACStacks

Thanx een. What is the actual size of the stem Diameter and length? I know its a flattened "D" shape.

Thanx, Twin


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## Joey Voltage

TwinACStacks said:


> Thanx een. What is the actual size of the stem Diameter and length? I know its a flattened "D" shape.
> 
> Thanx, Twin



you can get them here:

Antique Electronic Supply

click under "potentiometers", then click "Korg", they will only have 100KL for this application, sou you can just parallel it with a 100K resistor to get 50K. of course it woun't have a linear response when you do, but it wont be objectionable


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## TwinACStacks

Joey Voltage said:


> you can get them here:
> 
> Antique Electronic Supply
> 
> click under "potentiometers", then click "Korg", they will only have 100KL for this application, sou you can just parallel it with a 100K resistor to get 50K. of course it woun't have a linear response when you do, but it wont be objectionable



Thanx Joey. I mentioned them earlier in the thread but I wasn't sure if they were the same as in the DSL.

 TWIN


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## Buggs.Crosby

What can be done to give the classic channel a kick in the Ass?
I'd like to take it from being the wine tasting Frenchman and turn it into a Whiskey Drunken Irishmen


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## Joey Voltage

Buggs.Crosby said:


> What can be done to give the classic channel a kick in the Ass?
> I'd like to take it from being the wine tasting Frenchman and turn it into a Whiskey Drunken Irishmen



remove R12 on the pot board and jumper it. works only when the crunch mode is in.


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## jcmjmp

Joey Voltage said:


> remove R12 on the pot board and jumper it. works only when the crunch mode is in.



If you do that, the clean mode will sound quieter. Get the een7gdr clean/crunch footswitch mod so that you can adjust the levels between the two and get the added bonus of being able to footswitch between the two.


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## Buggs.Crosby

jcmjmp said:


> If you do that, the clean mode will sound quieter. Get the een7gdr clean/crunch footswitch mod so that you can adjust the levels between the two and get the added bonus of being able to footswitch between the two.



i already had contact with Graham just trying to decide whether or not to do both channels or not.....but i mean more gain....i don't want to use a pedal...if i cant get that then i'll use the foot switch mod on the ultra channel and tailor any mods i might try around that channel


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## TwinACStacks

Is there some type of adjustment Pot that could be used to equalize the Volume difference in Crunch /Clean and Red1/Red2 without the rigamarole of footswitching and all the Xtra electronics and PCBs?

 TWIN


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## Joey Voltage

jcmjmp said:


> If you do that, the clean mode will sound quieter. Get the een7gdr clean/crunch footswitch mod so that you can adjust the levels between the two and get the added bonus of being able to footswitch between the two.



It already does in comparison and that channel was really designed to choose one mode or the other. The whole amp is actually quite similar to the 5150 in this regard. the trick to this amp is really deciding whats important to you than working around everything else. the R12 thing I mentioned will increase gain a bit in the channel when in crunch mode, but yeah you pay for it. If having a more balanced clean tone is high on your priority list than it may not be what you want, but most people don't buy this amp soley for the clean mode on the classic gain channel either.


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## Buggs.Crosby

Joey Voltage said:


> It already does in comparison and that channel was really designed to choose one mode or the other. The whole amp is actually quite similar to the 5150 in this regard. the trick to this amp is really deciding whats important to you than working around everything else. the R12 thing I mentioned will increase gain a bit in the channel when in crunch mode, but yeah you pay for it. If having a more balanced clean tone is high on your priority list than it may not be what you want, but most people don't buy this amp soley for the clean mode on the classic gain channel either.



no use for clean what so ever....i'm thinking 3 modes of dirty
mode 1. whiskey drunken irishman
mode 2. shine running redneck
mode 3. firewater indian warpath
something along these tones


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## TwinACStacks

Just to let You guys know I did a little more tweaking. On R30 on the mainboard I piggybacked another 470K resistor on, so now the effective value of R30 is 190k (470k+1M+470k). It was 320k (470k+1M). I also changed C8 from .0015uf to .001uf. Still got plenty of Gain and hoping it's brightened some more. Won't know until I can crank it, so I have to wait until the wifey goes somewhere. Sounds good at low Volumes though....


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## jcmjmp

Buggs.Crosby said:


> no use for clean what so ever....i'm thinking 3 modes of dirty
> mode 1. whiskey drunken irishman
> mode 2. shine running redneck
> mode 3. firewater indian warpath
> something along these tones


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## Buggs.Crosby

R12 definitely made a big difference...a little darker though or so it seems...but i like so Thank You for it....the clean is not so bad till you get the gain up around 6-7....very usable


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## Wilder Amplification

jcmjmp said:


> If you do that, the clean mode will sound quieter. Get the een7gdr clean/crunch footswitch mod so that you can adjust the levels between the two and get the added bonus of being able to footswitch between the two.



This is the whole thing with modding...tradeoffs everywhere. 

I wonder if there's a mod you can do that switches a loading resistor across the Classic Gain channel master pot when in Crunch mode to compensate for this. Either a loading resistor across the pot or a series resistor that gets shunted in/out would accomplish this.


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## een7gdr

Wilder Amplification said:


> This is the whole thing with modding...tradeoffs everywhere.
> 
> I wonder if there's a mod you can do that switches a loading resistor across the Classic Gain channel master pot when in Crunch mode to compensate for this. Either a loading resistor across the pot or a series resistor that gets shunted in/out would accomplish this.



Ill have to check 100% but im sure that only 3 poles of the 4 pole switch are used, so a loading resistor could easily be wired in parallel to the pot using this spare pole to switch it in in crunch mode. I have no idea how this will effect the dynamics of the crunch mode however - but in conjunction to the other mods im sure itll work.


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## Wilder Amplification

een7gdr said:


> Ill have to check 100% but im sure that only 3 poles of the 4 pole switch are used, so a loading resistor could easily be wired in parallel to the pot using this spare pole to switch it in in crunch mode. I have no idea how this will effect the dynamics of the crunch mode however - but in conjunction to the other mods im sure itll work.



You know what? Now that I think about it these amps have the master pots joined together at the tone stack end so this would also affect the Lead channel master as well with the crunch setting selected. You would have to somehow separate the master pots in order to pull it off correctly, which would require yet another switching stage.


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## Joey Voltage

Buggs.Crosby said:


> R12 definitely made a big difference...a little darker though or so it seems...but i like so Thank You for it....the clean is not so bad till you get the gain up around 6-7....very usable



Is it the Irish man you were looking for? If it is too dark We can fix that!


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## Buggs.Crosby

Joey Voltage said:


> Is it the Irish man you were looking for? If it is too dark We can fix that!


yes but could we kick him in the nuts and piss him off a bit more?
and it's not really dark per say just maybe not as bright...i would love to have this tone in the red channel


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## Joey Voltage

Wilder Amplification said:


> You know what? Now that I think about it these amps have the master pots joined together at the tone stack end so this would also affect the Lead channel master as well with the crunch setting selected. You would have to somehow separate the master pots in order to pull it off correctly, which would require yet another switching stage.



Either way it would load the tonestack too much, and change the frequency response of the tonestack when the crunch is engaged, using something close to the mesa "solo" function in reciprocal, would probably be the easiest way. Then you have to ask: Is it really worth the hassel?


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## een7gdr

Wilder Amplification said:


> You know what? Now that I think about it these amps have the master pots joined together at the tone stack end so this would also affect the Lead channel master as well with the crunch setting selected. You would have to somehow separate the master pots in order to pull it off correctly, which would require yet another switching stage.



Your right, i forgot that i had to prevent the clean/crunch swither operating when the amp was in the red mode (as one of the install options changes the load resistance a little). Ill have a look and see if there are any unused poles of the main channel select relays that could also be used although i think they are pretty full !


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## Buggs.Crosby

anyone have a mod to get rid of the two useless knobs on the front of these things?


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## TwinACStacks

Jeez, That's funny. Since the Joey Mods and the finish tweaking I did last night, I HAVE NO USELESS KNOBS.....

*EVERYTHING* IS *(TITS)*. (Be proud Ladies, they are _wonderful._, 'Tis a compliment.)

 TWIN


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## Buggs.Crosby

even when i'm done mine next week i'll still have the two useless reverb knobs


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## TwinACStacks

Okay here's how You fix that, remove the silkscreening on the front panel that says "reverb", get some waterslide decals that say "Dry1" and "Dry2" and disconnect the reverb tank.

Problem solved. You now have a full Dry control for BOTH channels...

 TWIN

I can hook you up with a Great waterslide guy.


----------



## Buggs.Crosby

this head did not have a tank when i bought it....but i would have pulled it out anyway...never liked Marshall's verb or what little there is of it plus i have not used vrb in eons......but a deep pot and a foot switchable boost pot would be nice


----------



## Wilder Amplification

een7gdr said:


> Your right, i forgot that i had to prevent the clean/crunch swither operating when the amp was in the red mode (as one of the install options changes the load resistance a little). Ill have a look and see if there are any unused poles of the main channel select relays that could also be used although i think they are pretty full !



You know another thing I thought of...though it will probably involve cutting tracings on the pot board, but I wonder if it would be possible to break the connection between the Classic and Ultra master pots on the Classic master trace, solder in like a 220K resistor across the broken trace (which will place the 220K in series with the Classic Master pot), then wire up that unused relay pole to shunt/unshunt the resistor for the two different modes. This would have minimal effect on the tone stack loading and would limit the output when the Crunch setting is active, then shunt the resistor out when the Clean setting is active.


----------



## TwinACStacks

Had a Chance to play around with the Value of R30 some more today and discovered that the Fizzies appear on Lead 2 somewhere Between 190uf and 235uf values for R30. Tried all of them, kept it at 190uf. Of course there are trade offs here as well-you get a little more brightness on all Modes, lead1 and 2 sound fantastic, you can use the deep switch for added girth without boominess in ALL modes. BUT you sacrifice some gain on the Crunch Channel, (which some may not like), but there is still plenty, more if you CRANK it. (It's perfect for Vintage rock Tones). Also the Clean is WAY clean. Overall this thing is now sounding a little Plexi-ish, if Plexis had teeth.... BIG, LONG, friggin' TEETH.

 TWIN


----------



## Wilder Amplification

TwinACStacks said:


> Had a Chance to play around with the Value of R30 some more today and discovered that the Fizzies appear on Lead 2 somewhere Between 190uf and 235uf values for R30. Tried all of them, kept it at 190uf. Of course there are trade offs here as well-you get a little more brightness on all Modes, lead1 and 2 sound fantastic, you can use the deep switch for added girth without boominess in ALL modes. BUT you sacrifice some gain on the Crunch Channel, (which some may not like), but there is still plenty, more if you CRANK it. (It's perfect for Vintage rock Tones). Also the Clean is WAY clean. Overall this thing is now sounding a little Plexi-ish, if Plexis had teeth.... BIG, LONG, friggin' TEETH.
> 
> TWIN



Glad to see you like that R30 trick. That's one of my main tricks with the DSLs.


----------



## jcmjmp

Wilder Amplification said:


> Glad to see you like that R30 trick. That's one of my main tricks with the DSLs.



Thanks for sharing that with us!


----------



## TwinACStacks

Uh Oh, Did Wilder just divulge his secret weapon?

 TWIN


----------



## Buggs.Crosby

TwinACStacks said:


> Had a Chance to play around with the Value of R30 some more today and discovered that the Fizzies appear on Lead 2 somewhere Between 190uf and 235uf values for R30. Tried all of them, kept it at 190uf. Of course there are trade offs here as well-you get a little more brightness on all Modes, lead1 and 2 sound fantastic, you can use the deep switch for added girth without boominess in ALL modes. BUT you sacrifice some gain on the Crunch Channel, (which some may not like), but there is still plenty, more if you CRANK it. (It's perfect for Vintage rock Tones). Also the Clean is WAY clean. Overall this thing is now sounding a little Plexi-ish, if Plexis had teeth.... BIG, LONG, friggin' TEETH.
> 
> TWIN



is that cap wired in parralell with R30...or did you pull R30 and put the cap in it's place?...and did you try anything lower than 190uf?


----------



## TwinACStacks

Wired in parallel Buggs Yep, I tried an 82k which brought it down to roughly 68K value (470+82) I found out I had TWO CLEAN Green channels No Crunch-AT ALL. You can solder one resistor in R30's place once You determine what value You want, but by just tacking it across R30's legs it's easily changed in Value. Here is a calculator for up to 10 resistors in parallel:

http://www.1728.com/resistrs.htm

TWIN


----------



## Buggs.Crosby

TwinACStacks said:


> Wired in parallel Buggs Yep, I tried an 82k which brought it down to 68K value (470+82) I found out I had TWO CLEAN Green channels No Crunch-AT ALL. You can solder one resistor in R30's place once You determine what value You want, but by just tacking it across R30's legs it's easily changed in Value. Here is a calculator for up to 10 resistors in parallel: PARALLEL RESISTOR CALCULATOR
> TWIN



i certainly dont want to change the green at this point....it actually sounds the way Marshall described it in the hand book.....clean sounds close to my 59ri
and crunch now sounds like the 800 on steroids that they describe
all from two mods that Joey suggested...as soon as i can figure out why my guitar trax keeps closing i'll post some clips....i can record them but as soon as i hit the stop button the program closes in an error....anyone know of any clean freebie ware to use to get some samples up?

Between Joey and Jon my Marshall sounds like a Marshall and not what they are pushing out of the factory door....maybe Jim should hire these two as consultants or something....there amps would only benefit from them being on the design team


----------



## jcmjmp

Buggs.Crosby said:


> i certainly dont want to change the green at this point....it actually sounds the way Marshall described it in the hand book.....clean sounds close to my 59ri
> and crunch now sounds like the 800 on steroids that they describe
> all from two mods that Joey suggested...


Buggs, please describe which mods you did - It can be tough to follow what mods everyone is picking up.


----------



## Buggs.Crosby

jcmjmp said:


> Buggs, please describe which mods you did - It can be tough to follow what mods everyone is picking up.



the only one i can discuss is the r12 jumper....the other mod is not finished yet so untill i get the parts in i dont even want comment on it too much....lets just say Marshall had the green channel very wrong in their description....they should have called the stock tones....dead sperm for the clean...and sleeping homeless man for the crunch.....the "whiskey drunken Irishman mod" is more like their description...next up is the "Shine running Redneck mod" ...when it's all said and done i will post what i can on them....somethings i cannot and will not list though as they are not my mods


----------



## jcmjmp

Buggs.Crosby said:


> the only one i can discuss is the r12 jumper....the other mod is not finished yet so untill i get the parts in i dont even want comment on it too much....lets just say Marshall had the green channel very wrong in their description....they should have called the stock tones....dead sperm for the clean...and sleeping homeless man for the crunch.....the "whiskey drunken Irishman mod" is more like their description...next up is the "Shine running Redneck mod" ...when it's all said and done i will post what i can on them....somethings i cannot and will not list though as they are not my mods



So your mods have nothing to do with what is described here?


----------



## Buggs.Crosby

the only mods i could come up with on my own would be limited to just the tone stack and switching...and i have not gone there yet as i will not get any parts till about Wednesday. i have never really looked at the schematic too deeply as i dont understand every circuit in these heads...i'm am very far from being a Tech...nor will i ever profess to be one....but when i do learn something i make sure i understand it completely then try to exploit it
so yes...non of the mods i mentioned so far were of my own design....those will come next week....they could be great or turn into a waste of time but untill i try them i will never know


----------



## jcmjmp

Buggs.Crosby said:


> the only mods i could come up with on my own would be limited to just the tone stack and switching...and i have not gone there yet as i will not get any parts till about Wednesday. i have never really looked at the schematic too deeply as i dont understand every circuit in these heads...i'm am very far from being a Tech...nor will i ever profess to be one....but when i do learn something i make sure i understand it completely then try to exploit it
> so yes...non of the mods i mentioned so far were of my own design....those will come next week....they could be great or turn into a waste of time but untill i try them i will never know



Cool - Let us know how it turns out. 

The DSL tone stack is your typical Marshall tone stack. There's nothing special about it. The real differences lie in the channel mode tone shaping. You could remove most of the green channel's tone shaping in crunch mode and it would be very close to a JCM800 circuit.


----------



## Buggs.Crosby

jcmjmp said:


> Cool - Let us know how it turns out.
> 
> The DSL tone stack is your typical Marshall tone stack. There's nothing special about it. The real differences lie in the channel mode tone shaping. You could remove most of the green channel's tone shaping in crunch mode and it would be very close to a JCM800 circuit.



trust me when i say that my head is closer to a hot rodded 800 now then when Marshall was coming up with tag words to help it sell.....there are no need for stomp boxes with this head in the green channel

clean sounds real close to my 59ri....real close....crunch is exactly what i was looking for...BALLS with more Balls to spare....lets just say that kicking that drunken Irishman in the nuts was the best thing that ever happened to this head so far....and it can only get better

when it's done i'm gonna take it to G.C and act like i'm looking for a new head with this one as trade just so i can ask them why their head's sound like shit compared to mine.....should be pretty funny


----------



## Wilder Amplification

Buggs.Crosby said:


> is that cap wired in parralell with R30...or did you pull R30 and put the cap in it's place?...and did you try anything lower than 190uf?



OK I think we have a confusion of terms here so before you go out purchasing CAPS...lol

What he's doing is leaving R30 stock, but with jumper leads he's swapping RESISTORS in and out in parallel with the stock R30, then calculating the effective value. Once he finds a value he likes, he plans to replace the stock R30 with the closest standard value that matches the calculated value.

Just...figured I'd uh...clear that one up...ya know...before ya go buyin' the wrong parts...n' shit.


----------



## Buggs.Crosby

Wilder Amplification said:


> OK I think we have a confusion of terms here so before you go out purchasing CAPS...lol
> 
> What he's doing is leaving R30 stock, but with jumper leads he's swapping RESISTORS in and out in parallel with the stock R30, then calculating the effective value. Once he finds a value he likes, he plans to replace the stock R30 with the closest standard value that matches the calculated value.
> 
> Just...figured I'd uh...clear that one up...ya know...before ya go buyin' the wrong parts...n' shit.



Thanks for clearing that up Jon......i went back and re read that post
http://www.marshallforum.com/120093-post33.html..now i have it
whats a good high/low value range to play with here and C8


----------



## Joey Voltage

jcmjmp said:


> Buggs, please describe which mods you did - It can be tough to follow what mods everyone is picking up.



It was a couple I gave him off the record. They are not Open source though. Buggs kicked me some beer money for them, but since I drink PBR, I have like a lifetime supply.


----------



## Joey Voltage

Buggs.Crosby said:


> Thanks for clearing that up Jon......i went back and re read that post
> http://www.marshallforum.com/workbench/workbench/120093-post33.html..now i have it
> whats a good high/low value range to play with here and C8



I would leave C8 alone as it will thin out your Irishman a little. If that is what you want, I would go with .001 -.0022uf leaning towards .0022uf...which is what I originally suggested, but Stacks ended up choosing .001uf. and don't touch R30 leave it stock, as it will negate part of what you did


----------



## Buggs.Crosby

Joey Voltage said:


> I would leave C8 alone as it will thin out your Irishman a little. If that is what you want, I would go with .001 -.0022uf leaning towards .0022uf...which is what I originally suggested, but Stacks ended up choosing .001uf. and don't touch R30 leave it stock, as it will negate part of what you did


Cool Beans dude...and i have to say Joey Rocks
Dude even on 1 this thing just sounds incredible on crunch mode Thanks and then some....when the wife and kids go out i'm gonna wake that little fucker up and get him drunk again and let him beat the shit out of my ears some more


----------



## Buggs.Crosby

Joey Voltage said:


> It was a couple I gave him off the record. They are not Open source though. Buggs kicked me some beer money for them, but since I drink PBR, I have like a lifetime supply.


Thus the reason i would not post them....when you get handed something like this and are asked to keep it on the Down Low you do exactly that
and full Credit for this Drunken Irishman goes to Joey..nothing here was me or the NOS pre's as they were not in yet


----------



## Wilder Amplification

Buggs.Crosby said:


> Thus the reason i would not post them....when you get handed something like this and are asked to keep it on the Down Low you do exactly that
> and full Credit for this Drunken Irishman goes to Joey..nothing here was me or the NOS pre's as they were not in yet



You mean you're not gonna follow the example of "power strip boy" and post all your PMs from everyone for public record?


----------



## Buggs.Crosby

Wilder Amplification said:


> You mean you're not gonna follow the example of "power strip boy" and post all your PMs from everyone for public record?



Ha..Ha....i forgot about that dude....LOL...what an ass
Joey sent me a P.M to help me out.....that Ass sent an unsolicited rant attacking a highly esteemed member of this board....(Insert your name here) and never asked me not to post it

Powerstrip Boy should have stuck around...he have would loved these
http://www.marshallforum.com/tone-zone/13202-here-we-go-again-power-cord.html


----------



## TwinACStacks

Good Catch Jon, I answered him and never caught on to the fact he was asking about caps while I was talking about resistors...

 TWIN


----------



## Buggs.Crosby

Jon i can't find that thread...it was some funny shit i know that...and i wished i still had the P.M he sent me but i must have deleted it or maybe you cant save them that long
i do know it led to this quote


> =Buggs.Crosby;99456]Jon....are you E-mail back stabbing this overly inflated testosterone injecting Junkie like i did that Adam312 dude the other week?...... Shame on us for posting responses to the unsolicited slander we receive....I must now drink another 6 pack to repent my sins <--- i guess that last one was a light weight



and then i started this thread in responce to those couple of idiots that were here at the time
http://www.marshallforum.com/workbench/11838-ice-my-mains-60hz.html


----------



## Buggs.Crosby

Ha..Ha...i found it....what a classic
http://www.marshallforum.com/workbench/11176-ill-try-again.html


----------



## Buggs.Crosby

if i remove the reverb board that i dont need would i be ok using the +15v the schematic shows to power some relays?
i'm thinking of the circuit Jon posted a while back to switch out the choke so i am just wondering if i make a board to fit where the verb board was and load it using a relay to control the sag resistor/choke and using a second relay to to switch the Standby off and on using footswitches
i know some of this may sound a little crazy but there is a method to my madness...i just dont want to spend the time making a layout if the verb board has to remain as i'm not sure how it ties into the rest of the amps circuits
i'm also leaning towards Grahams clean/crunch switch for lead 1-2 and using another relay to activate the deep switch in and out
remember i have that Peavey midipro to do all the switching via a midi footswitch....but programing it will be a bit of a chore


----------



## Wilder Amplification

Buggs.Crosby said:


> if i remove the reverb board that i dont need would i be ok using the +15v the schematic shows to power some relays?
> i'm thinking of the circuit Jon posted a while back to switch out the choke so i am just wondering if i make a board to fit where the verb board was and load it using a relay to control the sag resistor/choke and using a second relay to to switch the Standby off and on using footswitches
> i know some of this may sound a little crazy but there is a method to my madness...i just dont want to spend the time making a layout if the verb board has to remain as i'm not sure how it ties into the rest of the amps circuits
> i'm also leaning towards Grahams clean/crunch switch for lead 1-2 and using another relay to activate the deep switch in and out
> remember i have that Peavey midipro to do all the switching via a midi footswitch....but programing it will be a bit of a chore



Yes you can pull out the verb board. Not sure though if the +15 volt supply can source enough current to power relays that can handle switching high voltages though.


----------



## jcmjmp

Joey Voltage said:


> It was a couple I gave him off the record. They are not Open source though. Buggs kicked me some beer money for them, but since I drink PBR, I have like a lifetime supply.


Ahh. So why tease us here? This thread was supposed to be about "open source" mods. 
Oh well... Glad to hear that his crunch tone is where he wants it.


----------



## TwinACStacks

Buggs.Crosby said:


> Ha..Ha...i found it....what a classic
> http://www.marshallforum.com/workbench/11176-ill-try-again.html



I found that he can't spell desperate, and since we are all from hoods-I'm from Detroit where we kill and eat our weak.

 TWIN


----------



## Joey Voltage

jcmjmp said:


> Ahh. So why tease us here? This thread was supposed to be about "open source" mods.
> Oh well... Glad to hear that his crunch tone is where he wants it.



True, but you are more than capable of coming up with your own versions, plus there is already tons of crap here to keep the brave tinkerer busy.


----------



## TwinACStacks

Joey, I'll bet you like Rolling Rock too. I thought all New Englanders drank Narragansett....

 TWIN


----------



## Buggs.Crosby

TwinACStacks said:


> Joey, I'll bet you like Rolling Rock too. I thought all New Englanders drank Narragansett....
> TWIN



when i lived in Medford it was mostly Coors....but i was still in my Turkey and Old G Dad days and never really drank much beer then....but that's what all my friends drank


----------



## Joey Voltage

Buggs.Crosby said:


> when i lived in Medford it was mostly Coors....but i was still in my Turkey and Old G Dad days and never really drank much beer then....but that's what all my friends drank



depends on who's drinking. If it is some shitty college kid mostly bud light



TwinACStacks said:


> Joey, I'll bet you like Rolling Rock too. I thought all New Englanders drank Narragansett....
> 
> TWIN



No.... It depends, we are kinda limited here (in my neighborhood, and in general). If I'm just picking up a 40, usually Pabst, Natty Ice, or High life, or a bottle of cheap bum wine. But If I'm buying a 12 pack it is usually harpoon. I'm originally from the PNW and there is enough out there to spoil a person into believing there really is not much difference between Pabst and harpoon.


----------



## Buggs.Crosby

Joey Voltage said:


> No.... It depends, we are kinda limited here (in my neighborhood, and in general). If I'm just picking up a 40, usually Pabst, Natty Ice, or High life, or a bottle of cheap bum wine. But If I'm buying a 12 pack it is usually harpoon. I'm originally from the PNW and there is enough out there to spoil a person into believing there really is not much difference between Pabst and harpoon.



you would probably love Genesee Cream on tap...not cans or bottles


----------



## Buggs.Crosby

so i was playing around with lead 1-2 last night...all is good untill i jumper r20 on the pb board
ass soon as i jump it lead 1 no longer works just lead 2...any suggestions?
i also clipped c12 i tried some other values there and the best was none so that's where i'll keep it....now if the rest of the parts would get here i can go further


----------



## Wilder Amplification

Buggs.Crosby said:


> so i was playing around with lead 1-2 last night...all is good untill i jumper r20 on the pb board
> ass soon as i jump it lead 1 no longer works just lead 2...any suggestions?
> i also clipped c12 i tried some other values there and the best was none so that's where i'll keep it....now if the rest of the parts would get here i can go further



What do you mean by "Lead 1 no longer works"? Are you getting no sound at all on Lead 1? Or are you not noticing a tone difference on Lead 1 as compared to Lead 2?


----------



## Buggs.Crosby

no sound at all...just preamp hiss


----------



## Wilder Amplification

Buggs.Crosby said:


> no sound at all...just preamp hiss



OK...what color bands do you have on R20?


----------



## Buggs.Crosby

it's shows brown/green/yellow which should be 150k...yet the schematic shows it should be 47k....just found it...i messed up and jumped r21...i guess it's time to put my granny glasses on....kinda sad when you need 2x magnifying glasses to read a f'ing board


----------



## Wilder Amplification

Buggs.Crosby said:


> it's shows brown/green/yellow which should be 150k...yet the schematic shows it should be 47k....just found it...i messed up and jumped r21...i guess it's time to put my granny glasses on....kinda sad when you need 2x magnifying glasses to read a f'ing board



Yeah that would completely ground out Lead 1, then unshunt it when you switch into Lead 2 which would take R21 out of the circuit and remove the ground shunt. 

And I'm sorry...I'm gonna have to laugh at you for that one.   jk


----------



## Buggs.Crosby

it's all good...maybe i should have smoked more weed when i was younger then my eyes might see better today......for now i'm leaving r20 off the board as it sounds better so far...at least closer to the crunch channel


----------



## TwinACStacks

They sure use small components in these don't they??

Same problem.

 TWIN


----------



## Buggs.Crosby

TwinACStacks said:


> Same problem.


your eyes are getting smaller too?


----------



## Wilder Amplification

Buggs.Crosby said:


> your eyes are getting smaller too?



That ain't all.


----------



## solarburn

Doh!

Laughing at all the senior moments too herhe!


----------



## TwinACStacks

Buggs.Crosby said:


> your eyes are getting smaller too?



Yep. But on the upside my package is getting bigger....

 TWIN


----------



## Landshark

.


----------



## Landshark

.


----------



## Uncle Beef

Well TwinAC told me to come over here.... so here I am. 

So heres the scoop after 20 years of playing I just got my first Marshall this week. Its a 2004 JCM 2000 DSL 50. I like the overall tone of it but there are few things about it I'm not fully happy with. One is the Bottom end is a little loose for me.

Background for you all the guitar i use primarily is a Dean razorback slime bee with the Dimebucker in the bridge. Fairly hefty guitar all mahogany body and neck with rosewood board. So its a pretty thick sounding guitar as is. But its my favorite axe so I want to keep using it with this amp.

The cab is a standard 1960a with the 4 celestion's in it. Dead stock.
Amp was re-tubed with JJ's on both power and preamp tubes and re-biased by one of the local amp tech's 6 months ago. barely been played since. 

The sound I'm going for just so you all know isn't your typical scooped signal. It needs to have some body (aka mid's) to it. however it has to have a tight and thick bottom end so i can chunk it good. (sounds like my dream girl come to think of it.) Highs i want to be fairly smooth sounding. Think of a combo between Dime and Bill Hines of Mastodon. Overall pissed off growl for a distortion sound not your typical high gain signal.

Sorry to post close to the same thing in two different threads. Just learning the boards more than anything right now. Looking forward to talking with everyone here. Looks like Wilder and Joey know their shit so this should be awesome.


----------



## jcmjmp

Uncle Beef: Read this post: http://www.marshallforum.com/marshall-amps/13719-new-boards-new-marshall.html#post123498

Start with that and get back to us. 

The G12T-75 should be plenty tight, so we know speakers are not the issue here.


----------



## Wilder Amplification

+1 on jcmjmp's analysis. It's not the speakers...it's the amp. Tightness is not something that DSLs in stock form are known for.

Read through this thread and you'll find that there are many mods that you can perform rather simply by swapping out a few components. The absolute first mod that should be done is to drop the value of C12 on the main PCB from the stock value of 4.7uF to something like a 1uF or lower. The 4.7uF gives that first gain stage a boost start corner frequency of 18Hz...way too low to be of any use to a guitar. That adds the lows way too early on and causes a lot of the low end muddiness/distortion that you hear and feel.

Another fav of mine is to drop the value of R17 on the main PCB down from the stock value of 220K to a 100K. That will lower the gain of the first stage a bit so you're not just slamming the crap out of everything way early on. You've got 5 gain stages that are active in Lead 1/2...you don't need a whole crapload of gain being added that early on. 

On the pot board, another fav of mine is to swap out C20 on the front PCB with the pots on it to a 0.002uF, which will phatten up your mids a bit.

Plenty of other mods on this thread to browse through...feel free to try them all out and use them to your advantage!


----------



## TwinACStacks

Jon, what version is the Mainboard that You are finding/referencing R17 on? Most are showing it with a Value of 4n7, or am I missing something? It's in the same proximity as R30 on the schematic?

 TWIN


----------



## Wilder Amplification

TwinACStacks said:


> Jon, what version is the Mainboard that You are finding/referencing R17 on? Most are showing it with a Value of 4n7, or am I missing something? It's in the same proximity as R30 on the schematic?
> 
> TWIN



4n7??? That's a cap!

I'm going off of the Issue 5 schematic from Dr Tube.

R17 is the 220K plate resistor on the very first gain stage.


----------



## Uncle Beef

JC and Wilder thanks for the info. Since it has new tubes already do you think i should start with the cap mod? Is there anyplace in particular that you all have found for good quality cap's and electronic goodies, or is the local radio shack a good a place as any.


----------



## Wilder Amplification

Uncle Beef said:


> JC and Wilder thanks for the info. Since it has new tubes already do you think i should start with the cap mod? Is there anyplace in particular that you all have found for good quality cap's and electronic goodies, or is the local radio shack a good a place as any.



Most of us use Mouser...pretty much any component value you can think of they've got it.

Mouser Electronics - Electronic Component Distributor


----------



## TwinACStacks

Wilder Amplification said:


> 4n7??? That's a cap!
> 
> I'm going off of the Issue 5 schematic from Dr Tube.
> 
> R17 is the 220K plate resistor on the very first gain stage.



Sorry My Bad, it's 4k7!!! On my schematic it shows that as R13/220k. R17 is 4k7 on V2

 TWIN


----------



## Wilder Amplification

Actually you are correct...my mistake. 

R13 is the one that I meant to refer to.


----------



## TwinACStacks

Hey, I'm EASY to confuse.

I can mix up 4n7 and 4k7, but I'm solid with the number 220. It's right after 219 and just before 221...

 TWIN


----------



## TwinACStacks

Uncle Beef said:


> JC and Wilder thanks for the info. Since it has new tubes already do you think i should start with the cap mod? Is there anyplace in particular that you all have found for good quality cap's and electronic goodies, or is the local radio shack a good a place as any.



Use the Wimas where possible. The Link for it is right under the mainboard section on the Joey mods 1st page themselves, it's highlighted in yellow. I put it there, it will take you right to the 1uf wima cap in question.

 TWIN


----------



## Joey Voltage

Wilder Amplification said:


> On the pot board, another fav of mine is to swap out C20 on the front PCB with the pots on it to a 0.002uF, which will phatten up your mids a bit.



You have to be careful with this one a bit, you will start to rob the rest of the bands of their effectiveness If you do the treble cap increase I would call it quits at .001uf.


----------



## Wilder Amplification

Joey Voltage said:


> You have to be careful with this one a bit, you will start to rob the rest of the bands of their effectiveness If you do the treble cap increase I would call it quits at .001uf.



Phuck it...try 'em both out...sweeten to taste. Not like it ain't easily reverse able if he doesn't like it at all.


----------



## jcmjmp

Joey Voltage said:


> You have to be careful with this one a bit, you will start to rob the rest of the bands of their effectiveness If you do the treble cap increase I would call it quits at .001uf.



I agree, changing C20 to 0.002uf on the front board is way too much. You'll lose the effectiveness of the mid control pot. Even 0.001uf is pushing it. I wouldn't go over the 700pf value (approx).

Changing the mid pot to a value of 50k (up to 100k) is a much better approach IMO, but more of a pain because you need to find a proper pot to fit on the PCB, or wire it up by hand.


----------



## Joey Voltage

jcmjmp said:


> I agree, changing C20 to 0.002uf on the front board is way too much. You'll lose the effectiveness of the mid control pot. Even 0.001uf is pushing it. I wouldn't go over the 700pf value (approx).
> 
> Changing the mid pot to a value of 50k (up to 100k) is a much better approach IMO, but more of a pain because you need to find a proper pot to fit on the PCB, or wire it up by hand.



you have to be carful here too, or you will esentially do the same thing and rob the bass and treble range. although tone stacks in high gain amps like these are not so cut and dry, and if either You or Jon is trying to base findings using something like Duncans TSC, it wont be an accurate model for what is going on. what it is modeling is small signal scenarios




Wilder Amplification said:


> Phuck it...try 'em both out...sweeten to taste. Not like it ain't easily reverse able if he doesn't like it at all.



Man...You do know that whole "Ph" sub for letter "F" thing went out in the 
90's right? I'm not even sure the Urban Black communities use that shit any more.


----------



## jcmjmp

Joey Voltage said:


> you have to be carful here too, or you will esentially do the same thing and rob the bass and treble range. although tone stacks in high gain amps like these are not so cut and dry, and if either You or Jon is trying to base findings using something like Duncans TSC, it wont be an accurate model for what is going on. what it is modeling is small signal scenarios



Totally agree. 

The Duncan TSC, theory and mathematical equations are a great tool but as you say, you can't really use that as the definitive guide. You're right. Experimentation is key, as is experience, like the kind of experience you have. That's irreplaceable and no theory can replace that.
The old mid pot trick is something that's been proven to work though.


----------



## Stymie13

Wilder Amplification said:


> The absolute first mod that should be done is to drop the value of C12 on the main PCB from the stock value of 4.7uF to something like a 1uF or lower. The 4.7uF gives that first gain stage a boost start corner frequency of 18Hz...way too low to be of any use to a guitar. That adds the lows way too early on and causes a lot of the low end muddiness/distortion that you hear and feel.



John, when you say main board you mean the tube board right? This is not the C12 on the front/pot board right? So, if I understand correctly replacing this resistor will tighten up the bottom end...right?


----------



## TwinACStacks

Stymie13 said:


> John, when you say main board you mean the tube board right? This is not the C12 on the front/pot board right? So, if I understand correctly replacing this resistor will tighten up the bottom end...right?



You are correct BUT it is a capacitor that is what "C" stands for. Also using the first link supplied in the actual Joey mod Make sure which Board Issue You have You can NOT rely on the board Identification Marking either!! Find Various components to correctly ID.

 TWIN


----------



## Wilder Amplification

Yep...on the valve board. This will definitely tighten up the lows some.


----------



## jcmjmp

Wilder Amplification said:


> Yep...on the valve board. This will definitely tighten up the lows some.



I was looking at the Silver Jubilee V1a cathode bypass cap and its set a 0.68uf. Those amps have a ton of bass too. Don't be afraid to go slightly lower than 1uf for the V1a cathode cap (C12 on the issue 5 tube board).


----------



## Stymie13

Wilder Amplification said:


> Yep...on the valve board. This will definitely tighten up the lows some.



Great thanks John. TWIN, I have read your sticky a hundred times and just wanted to thank you for taking the time to put it up. I have verified my board numbers/revisions and have the schematics. I'm sourcing a couple caps with the help of your links. I can't afford a choke and OT yet, so it's just one or two mods at a time with a good sampling period in between. Thanks!!


----------



## tweed

Buggs.Crosby said:


> trust me when i say that my head is closer to a hot rodded 800 now then when Marshall was coming up with tag words to help it sell.....there are no need for stomp boxes with this head in the green channel
> 
> clean sounds real close to my 59ri....real close....crunch is exactly what i was looking for...BALLS with more Balls to spare....lets just say that kicking that drunken Irishman in the nuts was the best thing that ever happened to this head so far....and it can only get better
> 
> when it's done i'm gonna take it to G.C and act like i'm looking for a new head with this one as trade just so i can ask them why their head's sound like shit compared to mine.....should be pretty funny



Lifting one end of R12 made the crunch channel come to life? Right now I use the DSL50 live with a loaded pedal board in front. Most of the time I am slamming the crunch side and OD2(with the gain around 3-4) with an SD-1 in front set to stun. It's a little over the top sometimes switching over to OD2 for solos, but it's the only thing that works for some of the tunes we do. Mostly Hard/Classic Rock stuff. 

I installed a choke a few months back and that was a great improvement along with installing a set of =C= 34's set around 38 - 40ma. If I could get more useable gain on the OD side of the house, and some actual drive out of the crunch channel and only use a boost once in a while, I would be a pretty happy camper.


----------



## TwinACStacks

Stymie13 said:


> Great thanks John. TWIN, I have read your sticky a hundred times and just wanted to thank you for taking the time to put it up. I have verified my board numbers/revisions and have the schematics. I'm sourcing a couple caps with the help of your links. I can't afford a choke and OT yet, so it's just one or two mods at a time with a good sampling period in between. Thanks!!




 That's how you do it Stymie. Glad I could help. That's why the DSL is so cool--it mods really well. Sometimes I think the engineers at Marshall left weak areas in their design on purpose just for us tweakers. There is a reason it's the Best selling Amp in Marshall's history. Once You get it where you want it, there isn't much out there that will touch it.

 TWIN


----------



## Buggs.Crosby

tweed said:


> and some actual drive out of the crunch channel and only use a boost once in a while, I would be a pretty happy camper.


try the mod Joey suggested on page 1...it is a great starting point to get where you want
to quote Joey "remove R12 on the pot board and jumper it. works only when the crunch mode is in"


----------



## tweed

Buggs.Crosby said:


> try the mod Joey suggested on page 1...it is a great starting point to get where you want
> to quote Joey "remove R12 on the pot board and jumper it. works only when the crunch mode is in"



Thanks BC I'll give it a shot. So basically unsolder R12(ceramic orange cap) and just run a wire in it's place?


----------



## jcmjmp

tweed said:


> Thanks BC I'll give it a shot. So basically unsolder R12(ceramic orange cap) and just run a wire in it's place?



No. R12 is a resistor, not a capacitor.


----------



## Buggs.Crosby

jcmjmp said:


> No. R12 is a resistor, not a capacitor.



+1
c12 is also on the lead channel....r12 is on the crunch....the two should not be confused....thanks for clearing that up JCM


----------



## Wilder Amplification

Buggs.Crosby said:


> +1
> c12 is also on the lead channel....r12 is on the crunch....the two should not be confused....thanks for clearing that up JCM



And these components are on the front board with the pots on it, not on the tube board.


----------



## TwinACStacks

Okay Jon, so say I want to get more ooomph out of the Crunch channel but I may not want to go full bore as jumpering R12 what Values would be good to try? (about mid way) BTW: R12 stock is 470k.

Thanx Twin


----------



## jcmjmp

TwinACStacks said:


> Okay Jon, so say I want to get more ooomph out of the Crunch channel but I may not want to go full bore as jumpering R12 what Values would be good to try? (about mid way) BTW: R12 stock is 470k.
> 
> Thanx Twin



I tried jumpering R12 and its not that drastic. Try it and see. 
If you still think its too much, try something like 100k.


----------



## TwinACStacks

jcmjmp said:


> I tried jumpering R12 and its not that drastic. Try it and see.
> If you still think its too much, try something like 100k.



Thanx JC. That R30 mod made the amps Tone exactly where I want it but it also took just a Hair too much gain off the Crunch Channel. I don't want to change the tone/gain of anything else at all, it's perfect. If need be I can live with it the way it is. But if it just affects the Crunch mode this sounds like the finishing touch to a Really formidable modded amp. That and Your PT, of course.

 Twin


----------



## jcmjmp

Wilder Amplification said:


> +1 on jcmjmp's analysis. It's not the speakers...it's the amp. Tightness is not something that DSLs in stock form are known for.
> 
> Read through this thread and you'll find that there are many mods that you can perform rather simply by swapping out a few components. The absolute first mod that should be done is to drop the value of C12 on the main PCB from the stock value of 4.7uF to something like a 1uF or lower. The 4.7uF gives that first gain stage a boost start corner frequency of 18Hz...way too low to be of any use to a guitar. That adds the lows way too early on and causes a lot of the low end muddiness/distortion that you hear and feel.
> 
> Another fav of mine is to drop the value of R17 on the main PCB down from the stock value of 220K to a 100K. That will lower the gain of the first stage a bit so you're not just slamming the crap out of everything way early on. You've got 5 gain stages that are active in Lead 1/2...you don't need a whole crapload of gain being added that early on.



Wilder - could you edit your post to describe which tube board board version and issue you are referring to? i.e.: I think that you mean the plate resistor on V1a for R17?


----------



## jcmjmp

TwinACStacks said:


> Thanx JC. That R30 mod made the amps Tone exactly where I want it but it also took just a Hair too much gain off the Crunch Channel. I don't want to change the tone/gain of anything else at all, it's perfect. If need be I can live with it the way it is. But if it just affects the Crunch mode this sounds like the finishing touch to a Really formidable modded amp. That and Your PT, of course.
> 
> Twin



R12 on the front board only affects the crunch channel. Adjust to taste.


----------



## TwinACStacks

jcmjmp said:


> Wilder - could you edit your post to describe which tube board board version and issue you are referring to? i.e.: I think that you mean the plate resistor on V1a for R17?



JC I all ready asked him about this it's *R13 on the Issue 5 Board* Its Back 1 page. Jon boo-booed.

 TWIN


----------



## Buggs.Crosby

Hey Twin...have you ever tried removing r20 altogether?....that is my current r20 mod.....nothing


----------



## Buggs.Crosby

jcmjmp said:


> I tried jumpering R12 and its not that drastic. Try it and see.
> If you still think its too much, try something like 100k.



i agree...i didn't think it was much until Joey gave me the other mod...they work well together 

i finally have all my parts and may even go pick my head up today.....but that also means playing thru a SS Vox.....oh joy


----------



## TwinACStacks

Buggs.Crosby said:


> Hey Twin...have you ever tried removing r20 altogether?....that is my current r20 mod.....nothing



 Buggs I jumpered R20 on the Frontboard. Check out the actual Joey Mods on Page 1 especially Joeys explanation for it, Jumpering it made a HUGE difference.

 TWIN


----------



## Buggs.Crosby

TwinACStacks said:


> Buggs I jumpered R20 on the Frontboard. Check out the actual Joey Mods on Page 1 especially Joeys explanation for it, Jumpering it made a HUGE difference.



i thought it made a bigger impact without anything at all.....it took even more of the harshness out than just jumping it.....but the channels also seem alot closer together...yet my mids.trebs and presence are still only around three....cuts like a motherfucker though....our other guitar player bought the spider valve and before he bought it i warned him that we might not hear him and it would not be a volume issue.........boy did i call that one


----------



## TwinACStacks

Okay I removed the 470K Resistor from R12 and Jumpered it. I absolutely HATE it. Way too nasally, it gave me too much OD and took away most of the Bass from the Crunch. Any suggestions? would 330K give me a TAD more OD without stripping all the Bass out too? Admittedly the Crunch channel is a Hair Dark it could use just a Tad more highs, BUT NOT THIS FRIGGIN' MUCH....

 TWIN


----------



## jcmjmp

TwinACStacks said:


> Okay I removed the 470K Resistor from R12 and Jumpered it. I absolutely HATE it. Way too nasally, it gave me too much OD and took away most of the Bass from the Crunch. Any suggestions? would 330K give me a TAD more OD without stripping all the Bass out too? Admittedly the Crunch channel is a Hair Dark it could use just a Tad more highs, BUT NOT THIS FRIGGIN' MUCH....
> 
> TWIN



Weird - I didn't notice a loss of bass and I can't say its too much OD. The extra OD is noticeable but its not a huge increase IMO. 

As for the crunch sounding dark in stock form - I just don't agree. Its plenty bright.

I don't think I really like R12 jumpered. I find that the amp sounds a lot smoother with that resistor in place. Perhaps changing it to something like 100k would be better. more mids with better shelving in the upper frequencies.


----------



## TwinACStacks

But what are the effects coupled with other mods we've done? Remember I played around with R30 which decreased the fizz/Gain but also added brightness to everything. It may not be a Loss of Bass as much as an increase of treble. I now get Icepick and some Feedback I didn't have before, when using the Bridge Humbucker.

 TWIN


----------



## Joey Voltage

TwinACStacks said:


> But what are the effects coupled with other mods we've done? Remember I played around with R30 which decreased the fizz/Gain but also added brightness to everything. It may not be a Loss of Bass as much as an increase of treble. I now get Icepick and some Feedback I didn't have before, when using the Bridge Humbucker.
> 
> TWIN



you also lowered the coupling cap value of that channel too to something like .001uf, combine that with the peaker across the pot, and you will have a very steep rollof of bass which is what you are hearing. If you do this, I would leave the stock .0047uf value in, like Buggs did.


----------



## TwinACStacks

Got it Joey. I'll either restore R12 back to or near the 470K value. While I've got it apart I'll just do a little experimenting with a Pair of test leads and some different values.....

 TWIN


----------



## jcmjmp

.


----------



## Buggs.Crosby

TwinACStacks said:


> Okay I removed the 470K Resistor from R12 and Jumpered it. I absolutely HATE it. Way too nasally, it gave me too much OD and took away most of the Bass from the Crunch. Any suggestions? would 330K give me a TAD more OD without stripping all the Bass out too? Admittedly the Crunch channel is a Hair Dark it could use just a Tad more highs, BUT NOT THIS FRIGGIN' MUCH.... TWIN


i did wind up with my bass around 5-6 which is a little higher than i ran before.
but i don't think it was that drastic.....maybe Joeys other mod picked it back up as the whole green channel (clean and crunch) have a lot more punch to them
and i agree with JCM on that i never found the green to be dark....if anything i would call the red channel in stock form dark and pissy .....try removing r20 on the red and see if you like it....it has a very drastic affect....then again you have done other mods so it may not have the same affect


----------



## TwinACStacks

Answer: 220K

Question: Hey Twin, What did you finally settle on for R12?

 TWIN


----------



## Stymie13

TWIN, I've been reading this thread too much apparently. Now I'm confused. What values did you end up with on the main board for R30 and R13 and what were the audible results? I'm trying to just place one order for a couple more mods I want to try.


----------



## TwinACStacks

Stymie, some of the Mods are "season to taste" or simply: play with the Values until It sounds good to Your ears. Here were my issues when I first Started. I didn't like the Red Channels as they were to Bright, thin and Fizzy, and WAY too much Gain for My tastes. After Doing the original Mods I found we had cured the Brightness and thinness of the Red but still hadn't gotten all of the Fizzies gone plus I still had more Gain than I needed. Unfortunately some of the Mods ALSO affect the Green Channel making it a little Darker and as such really too much if I wanted to use the Bass Boost. So with the help of Jon, Joey, and JC, I refined the tweaks even more with the following Mods:

R30 replaced with resistors valuing 190K total. This Brought the Fizziness Down and added some Brightness for all Channels ( I tried several values for periods of time. For me this particular mod was the Hardest to get right to my ears.)

C8 Changed Value from .0015 (as per the original mod value) to .001 uf to control Boominess in Green Channel with Bass Boost on.

R12 Replaced Stock 470K with 220K for a Slight Gain increase in the Crunch Channel and a Tad more Brightness. This is the one I did last. I didn't care for it jumpered, as with the Mods we already had, I lost my Bass out of the Green Channel and got Ice-pick highs.

Now it sounds like I want it to. I may still have to adjust R12 but I think its close at 220K. If anything I will go towards a lower value, as going towards 470K darkens it back up considerably quickly, and around 1K it gets icepicky.

I never messed with R13 BTW, other Mods in the original Joeys already addressed that.

 TWIN


----------



## TwinACStacks

I keep seeing issues with "Loose or Flabby Bass" that need being addressed. THE best mod I found is to Change the Grid blockers to 5k6 from 220K. Really tightens it up, That and a new OT and Choke.

 TWIN


----------



## jcmjmp

TwinACStacks said:


> Answer: 220K
> 
> Question: Hey Twin, What did you finally settle on for R12?
> 
> TWIN



Yeah, that's what I ended up going with. Much better that R12 Jumpered IMO.

I think that his mod definitely sounds better with the V1a plate to cathode cap mod and cathode bypass cap mod.


----------



## Hamohapic

TwinACStacks said:


> I keep seeing issues with "Loose or Flabby Bass" that need being addressed. THE best mod I found is to Change the Grid blockers to 5k6 from 220K. Really tightens it up, That and a new OT and Choke.
> 
> TWIN



Hey Twin, 

What is a grid blocker, where is the location on the board for it? 

I just did a choke and OT install. Love the improvement so far. I am thinking of trying to do this mode you did but i am not sure where that part is at?

Thanks


----------



## Wilder Amplification

Hamohapic said:


> Hey Twin,
> 
> What is a grid blocker, where is the location on the board for it?
> 
> I just did a choke and OT install. Love the improvement so far. I am thinking of trying to do this mode you did but i am not sure where that part is at?
> 
> Thanks



The grid swamper resistors are R7, R10, R66 and R70.

Only the older models had 220K (red/red/yellow color bands) swampers. Yours may already have the 5K6 swampers (green/blue/red color bands).


----------



## Hamohapic

Wilder Amplification said:


> The grid swamper resistors are R7, R10, R66 and R70.
> 
> Only the older models had 220K (red/red/yellow color bands) swampers. Yours may already have the 5K6 swampers (green/blue/red color bands).



ahhh ok Ill take a look and see what I have before I do anything.


----------



## jcmjmp

Wilder Amplification said:


> The grid swamper resistors are R7, R10, R66 and R70.
> 
> Only the older models had 220K (red/red/yellow color bands) swampers. Yours may already have the 5K6 swampers (green/blue/red color bands).



but depending on the version of the board you have in your amp, they could be different resistors and part reference numbers, so be careful.

Before you do anything, make sure that you know which board you have. Have a look at the info here to determine how to do this:
http://www.lydian.ca/Marshall_DSL.html

Scroll down to the board info and schematics.


----------



## Hamohapic

jcmjmp said:


> but depending on the version of the board you have in your amp, they could be different resistors and part reference numbers, so be careful.
> 
> Before you do anything, make sure that you know which board you have. Have a look at the info here to determine how to do this:
> Marshall DSL
> 
> Scroll down to the board info and schematics.



Hey jcmpmp, i have the jcm2-60-00-iss1 board. I guess the best part is to find the resistors on the board and the values before changing anything.


----------



## jcmjmp

Hamohapic said:


> Hey jcmpmp, i have the jcm2-60-00-iss1 board. I guess the best part is to find the resistors on the board and the values before changing anything.



Cool - So on those boards, which are quite good BTW, the grid blockers and R55, R58, R62 and R70.

Replacing those with 5.6K should give you a little more top end. Marshall changed these resistors to better values on later boards.


----------



## Wilder Amplification

jcmjmp said:


> Cool - So on those boards, which are quite good BTW, the grid blockers and R55, R58, R62 and R70.
> 
> Replacing those with 5.6K should give you a little more top end. Marshall changed these resistors to better values on later boards.



I believe those values also had something to do with the bias drift issue that the earlier heads had since they are part of the grid leak circuit.

Now when you change those resistors out, make sure you order up some cryogenically treated super titanium ones from JCMJMP. Only then will you notice just what your tone can do for you.


----------



## TwinACStacks

Wilder Amplification said:


> I believe those values also had something to do with the bias drift issue that the earlier heads had since they are part of the grid leak circuit.
> 
> Now when you change those resistors out, make sure you order up some cryogenically treated super titanium ones from JCMJMP. Only then will you notice just what your tone can do for you.



 Oh man.... You mean I gotta take this sucker apart AGAIN?

 TWIN


----------



## Wilder Amplification

TwinACStacks said:


> Oh man.... You mean I gotta take this sucker apart AGAIN?
> 
> TWIN



Yep. Might I add that they also have to be NOS.


----------



## TwinACStacks

I just got off the phone with mouser. I asked for NOS Cryogenically treated super-duper Titanium resistors.

The customer service guy told me I could probably get them from Wilder Amplification, and that they were out of stock of those particular resistors.....


 TWIN


----------



## jcmjmp

I have a special option for the transformers: Its the radioactive cryo treatment, while being bombarded with the audio waves of the artist's tone you're after. 
They beat anything that on the market in terms of snake oil and fairy dust content


----------



## Hamohapic

You guys are riot "NOS Cryogenically treated super-duper Titanium resistors" l


----------



## Buggs.Crosby

Hamohapic said:


> You guys are riot "NOS Cryogenically treated super-duper Titanium resistors" l


let me guess you bought those tone dead metal films....those cryogenic ones are not only known for tone but your tubes will run cooler thus extending their life.......me i'll pay the $50 a pop for the good ones


----------



## Hamohapic

Buggs.Crosby said:


> let me guess you bought those tone dead metal films....those cryogenic ones are not only known for tone but your tubes will run cooler thus extending their life.......me i'll pay the $50 a pop for the good ones



wait you are not serious now right?? Listen man i don't know about resistors much but i thought you guys are playing around. lmao


----------



## jcmjmp

Buggs.Crosby said:


> let me guess you bought those tone dead metal films....those cryogenic ones are not only known for tone but your tubes will run cooler thus extending their life.......me i'll pay the $50 a pop for the good ones



I'll sell you mine for 40.... just for you...  I've got an endless supply of them.


----------



## solarburn

Hamohapic said:


> wait you are not serious now right?? Listen man i don't know about resistors much but i thought you guys are playing around. lmao



Yep. They're seriously play'n around.


----------



## Joey Voltage

Wilder Amplification said:


> I believe those values also had something to do with the bias drift issue that the earlier heads had since they are part of the grid leak circuit.



You can usually go quite high on those, and will probably work pretty well if you design the pa to clip hard, but anything above 100K is pushing it. Unless you buy those laser grooved Lutetium resistors, with the plated copper leads, not the steel ones.


----------



## Buggs.Crosby

jcmjmp said:


> I'll sell you mine for 40.... just for you...  I've got an endless supply of them.



I assume that $40 is already quantity pricing?


----------



## Joey Voltage

Buggs.Crosby said:


> I assume that $40 is already quantity pricing?



just waituntil you find out how much the lutetium ones costs... no tier pricing


----------



## thrawn86

What about Gold-Pressed Latinum capacators?


----------



## Wilder Amplification

thrawn86 said:


> What about Cold-Pressed *Latin*um capacators?



Those will make it pick up spanish radio stations.


----------



## thrawn86

So they're better than the ones made with Dilithium Crystals?


----------



## thrawn86

Or should I blow my money on a PTP board made from Tritanium?


----------



## Hamohapic

Question for you guys, what terminals do you guys use to discharge the capacitors on DSL 50's?

Thanks


----------



## jcmjmp

Hamohapic said:


> Question for you guys, what terminals do you guys use to discharge the capacitors on DSL 50's?
> 
> Thanks



They discharge themselves. Just leave your voltmeter on the plate pins - You'll see the voltage drop fairly quickly.


----------



## Hamohapic

jcmjmp said:


> They discharge themselves. Just leave your voltmeter on the plate pins - You'll see the voltage drop fairly quickly.



Ohh ok thanks man that is good to know. I understand that tube amps store a lot of voltage even when they are unplugged so I figure I ask.


----------



## Wilder Amplification

Hamohapic said:


> Ohh ok thanks man that is good to know. I understand that tube amps store a lot of voltage even when they are unplugged so I figure I ask.



+1. The screen filters have bleeder resistors on them that bleed the charge off once power is removed.


----------



## Buggs.Crosby

Wilder Amplification said:


> +1. The screen filters have bleeder resistors on them that bleed the charge off once power is removed.


i knew the was a reason i did not get shocked when i tried to drain them with my tongue....i was withdrawing and looking for a Buzz


----------



## Stymie13

Well... I finally got to play the ol' DSL 100 today after some tinkering. WOW what a different animal. I found myself constrained by my tendency to want to use my old EQ settings. Forget it. This thing is really different. Seems more clear. Definitely WAY less buzzy, but way less gain too. I find the best sounds with the treble off (seems kinda harsh) using the presence instead (which I never used to use), mid at about 8, and bass 5. Tone shift and Deep off. This is definitely going to take some time to dial in . Here's what I did:

front board:
C12 removed
R20 jumped

main board:
C12 1uf 63V
R30 220K
R7 5K6
R10 5K6
R66 5K6
R70 5K6

The only problem I've discovered so far is there is no Lead 1 with the front or foot switch. When in the Lead 1 switch position, there is no output. Both Classic channels work. Any ideas?


----------



## Stymie13

Test cab photo...


----------



## TwinACStacks

Check very carefully, It sounds like you jumped r21 instead of r20 Double check the numbers. This will take lead 1 out of the circuit. It's real easy to make this mistake the components are tiny.... If you need more gain increase R30 say to 330 or so.

 TWIN


----------



## Buggs.Crosby

TwinACStacks said:


> Check very carefully, It sounds like you jumped r21 instead of r20 Double check the numbers. This will take lead 1 out of the circuit. It's real easy to make this mistake the components are tiny.... If you need more gain increase R30 say to 330 or so.
> 
> TWIN



i did the same i think.....it's a page or two back.....try it without the jumper also...i liked it so i kept it empty


----------



## Buggs.Crosby

here ya go
http://www.marshallforum.com/122170-post82.html


----------



## Stymie13

I can't believe how many times I've read this thread... and missed that. Thanks all!!!!


----------



## 6StringMoFo

OK I changed my TXs to Mercury Mags

MAR100-P Power (Huge) 
MAR100-OM Output
MAR100-C Choke
(Thx Jon)

It took me 4 beers to do the mod and transfer and I managed to not fry anything. The sound is definitely tighter on the bass and midrange but I still have that high buzz shrilling happenen an things seem to have gotten a tad muddy.

Any ideas?


----------



## Buggs.Crosby

your gonna have to give the trannys some time.......same as a speaker.....it will open up.....crank it as much as you can.....you should "feel" the difference


----------



## Buggs.Crosby

i wouldn't do to many mods until they break in


----------



## 6StringMoFo

ok, maybe muddy was a bad picture word, definitely Darker than I anticipated


----------



## 6StringMoFo

LOL Maybe I'll feed my ipod into it and walk away for a day


----------



## Buggs.Crosby

it will be darker.....give them some time to break in.....combine them with a few of the mods posted and you will cherish that amp instead of just playing thru it


----------



## Stymie13

Stymie13 said:


> Well... I finally got to play the ol' DSL 100 today after some tinkering. WOW what a different animal. I found myself constrained by my tendency to want to use my old EQ settings. Forget it. This thing is really different. Seems more clear. Definitely WAY less buzzy, but way less gain too. I find the best sounds with the treble off (seems kinda harsh) using the presence instead (which I never used to use), mid at about 8, and bass 5. Tone shift and Deep off. This is definitely going to take some time to dial in . Here's what I did:
> 
> front board:
> C12 removed
> R20 jumped
> 
> main board:
> C12 1uf 63V
> R30 220K
> R7 5K6
> R10 5K6
> R66 5K6
> R70 5K6
> 
> The only problem I've discovered so far is there is no Lead 1 with the front or foot switch. When in the Lead 1 switch position, there is no output. Both Classic channels work. Any ideas?



Whoops!! I have a JCM02-60-00 main board. Looks like I'm going back in to the main board...


----------



## Stymie13

jcmjmp said:


> Cool - So on those boards, which are quite good BTW, the grid blockers and R55, R58, R62 and R70.
> 
> Replacing those with 5.6K should give you a little more top end. Marshall changed these resistors to better values on later boards.



So since this is the board I actually have should I leave the 5K6 resistors at the positions I installed them or should I replace them with the original 220Ks? I need to go back in anyway to install the 5K6s in the correct positions for this revision.


----------



## Stymie13

JCMJMP are you sure about the locations for the JCM2-60-00 version? R58 is empty on mine and R62 is a very large (5W?) 1000 ohm resistor.


----------



## Stymie13

jcmjmp said:


> Cool - So on those boards, which are quite good BTW, the grid blockers and R55, R58, R62 and R70.
> 
> Replacing those with 5.6K should give you a little more top end. Marshall changed these resistors to better values on later boards.



Sorry... this is what I was referring to.


----------



## jcmjmp

Stymie13 said:


> JCMJMP are you sure about the locations for the JCM2-60-00 version? R58 is empty on mine and R62 is a very large (5W?) 1000 ohm resistor.



I'm going by the Issue 1, JCM2-60-00 board. 
The 50w would only have R62/R58.

You can find the schematics here: 
Marshall DSL

You could just trace it back too. Its pretty simple because those resistors go directly to the grids on the EL34s.


----------



## 6StringMoFo

I got a solid bias lock with .2 .3 MV fluctuation around 88.9 MV That a good setting? Doesn't "Seem" to be as dark as when I had it set to 82 MV


----------



## Stymie13

Went back in and corrected my mistake. Thanks for the pointer Buggs... you were right. Also added the C10(front board) and C9(main board) mods. Man, this thing is a BEAST!! It sounds way thicker than it used to especially with single coils. Have I mentioned I love this forum? Now I just gotta get a new jam space where I can unleash this monster...


----------



## Buggs.Crosby

Stymie13 said:


> Went back in and corrected my mistake. Thanks for the pointer Buggs... you were right. Also added the C10(front board) and C9(main board) mods. Man, this thing is a BEAST!! It sounds way thicker than it used to especially with single coils. Have I mentioned I love this forum? Now I just gotta get a new jam space where I can unleash this monster...



seems like your down to just a tranny mod if you still need more


----------



## Stymie13

Buggs.Crosby said:


> seems like your down to just a tranny mod if you still need more



Indeed! I'm trying to save up the funds for an OT and a choke, but I am very happy with it the way it is.


----------



## Stymie13

After playing for a while today with humbuckers and single coils, I think my red channel is a little dark or bassy for my taste. It seems kinda almost muffled or something. I don't really know how to describe it. If I EQ the green channel for a balanced bottom end and top end sparkle, the red channel is too bassy or dark. I never played with R12. Any suggestions?

C12 remove
C10 .0022uf
R20 Jumper

C9 .001uf
C12 1uf
R30 220K
grid blockers 5K6


----------



## Buggs.Crosby

R12 is in the crunch circuit.....i used a jumper on it....gave the crunch some more bite


----------



## Buggs.Crosby

you are talking about the pot board correct?


----------



## Stymie13

Yeah, my crunch channel is just right. I think I need to brighten up the lead a bit. I did notice the clean mode on the green channel is significantly quieter than the crunch mode. It may have been that way before an I just didn't notice since I never use that mode.


----------



## Buggs.Crosby

i'm just getting into the red finally....a little has been done but not much yet
instead i have the Drunkin Irishman mod from Joey.....i dont really do clean so we hoped up the green a bit....i cant tell you what was done but i can show you what can be done to the green on a DSL....this is a shitty vid recorded with a mike for a Wii....it is not about tone or playing....merely to show the gain .....all gains are maxed and the volume is under one...(just audible enough to record and not clip)
[ame=http://www.youtube.com/watch?v=ADYxJqguGx0]YouTube - 4 up 4 down.mpg[/ame]


----------



## Stymie13

That is one pissed Irishman!!


----------



## Buggs.Crosby

Yeah.....he got kicked in the nuts!


----------



## Stymie13

Wow... I guess I need to start playing with a band again. My amps sounds worse today than I can ever remember. I must just be obsessing and trippin myself out. The red channel is buzzy and dull. Neck position pickups are just awful! No definition or character. I can't ever remember it sounding this lifeless. The green still seems to be full and jangly sweet.


----------



## Stymie13

OK, I'm not loosing it. I went back in and double checked some work. I found a crappy solder joint where I corrected a previous mistake on R21 on the pot board. One leg was totally loose. I also added the 1M resistor on VR3. I don't know which one fixed it but I suspect it was my shoddy work from before that came loose. My amp has all the character, tone, dynamic, punch, and note definition again!!! This thing is UNREAL!!! No buzz, no mud, singing sustain, and crystal clarity.


----------



## TwinACStacks

Yep, You gotta be real careful the components are way to tiny for us oldsters to see.

These "Joey mods" are the shit aren't they. You won't BELIEVE what they fucking sound like with new Trannies and a Choke. I'm gonna get a "badge" Made up.


 TWIN


----------



## TwinACStacks

Something Like:

_Joey_
DSL _Modded_

 TWIN


----------



## Buggs.Crosby

how about just a JSL.....or steal the JVM....or a Joey 2000?


----------



## TwinACStacks

Possible...

 TWIN


----------



## 93DMTX

Love this thread. Taking it one at a time.

But one thing I want to get done ASAP is the bridging of the output grounds.

Does anyone have a picture of how they physically did it. Thanks!

Doug


----------



## 6StringMoFo

What can you good folks tell me about pulling 2 tubes, either A-D or B-C.

Will I have to re-bias? Currently set to 88 mV
Use the 8 Ohm output into the 16 Ohm of my 60A?
Your cork sniffing, just use your 16 Ohm Hotplate and like it.

 Thx


----------



## Wilder Amplification

6StringMoFo said:


> What can you good folks tell me about pulling 2 tubes, either A-D or B-C.
> 
> Will I have to re-bias? Currently set to 88 mV
> Use the 8 Ohm output into the 16 Ohm of my 60A?
> Your cork sniffing, just use your 16 Ohm Hotplate and like it.
> 
> Thx



First off...if you pull two valves, you have to pull either A-D or B-C (inner or outer pair) so you got that part correct.

Then use your 8 ohm output into your 16 ohm load.

Always check bias when pulling two valves...adjust if necessary. However, with only two valves in your bias spec drops in 1/2 to 45mV max just like a 50 watt because you have two less valves to control the current (pulling two valves essentially turns it into a DSL50 so the DSL50 spec applies at that point).


----------



## Buggs.Crosby

other than the cost of the extra 2 valves i have found no benefit to running just a a pair
i am only running a pair still and until another swap or two i will leave it that way....this way i will buy a quad...2 hit the amp....2 hit the shelves....and when i switch back i will have 2 quads as backups.....other than that the only difference i hear is a very small drop in low end


----------



## Buggs.Crosby

93DMTX said:


> Love this thread. Taking it one at a time.
> 
> But one thing I want to get done ASAP is the bridging of the output grounds.
> 
> Does anyone have a picture of how they physically did it. Thanks!
> 
> Doug



if someone does not post a pic tonight i will post one tomorrow when i pull my chassis


----------



## 93DMTX

Buggs.Crosby said:


> if someone does not post a pic tonight i will post one tomorrow when i pull my chassis



Thanks man!

No rush 'cause I got it put back together for today. Luv'n it.

So far :

1. Verified R7, R10, R66, R70...my iss6 board already had 5k6
2. Jumped R20 on front bd
3. Removed C12 on front bd
4. Padded R30 on main bd with another 470K

Wish I could easily A/B now 'cause I sure like it better.

Funny, Lead1 is right there where I want it, perfect, BUT I'VE KILLED Lead2. It's mute when selected. The funniest thing is I like 1 so much that I hate to mess with trying to fix 2 - but I'll have to. 

Also, on the output ground buss, is it possible this was fixed on later models(late 2005)? I ASSUMED (haha) that plugging a connector into the 16 Ohm jack would open the ckt from the 4/8 Ohm jacks metal bands to chassis ground. It doesn't seem to. Didn't investigate to far cause I wanted to hear the mods so I could be totally wrong.

Anyways thanks a bunch to all y'alls for all the fine work here.


----------



## Buggs.Crosby

93DMTX said:


> Thanks man!
> 
> BUT I'VE KILLED Lead2. It's mute when selected.


Sounds like you jumped r21 instead....a bunch of us have made that mistake


93DMTX said:


> Also, on the output ground buss, is it possible this was fixed on later models(late 2005)? I ASSUMED (haha) that plugging a connector into the 16 Ohm jack would open the ckt from the 4/8 Ohm jacks metal bands to chassis ground. It doesn't seem to. Didn't investigate to far cause I wanted to hear the mods so I could be totally wrong.
> 
> Anyways thanks a bunch to all y'alls for all the fine work here.



not that i know of they have never changed it


----------



## 93DMTX

Buggs.Crosby said:


> Sounds like you jumped r21 instead....a bunch of us have made that mistake



Yea, I'm sure I did something along those lines. 

I was wrong earlier its Lead 1 that is mute. Lead 2 is present and accounted for and is phenomenal.


----------



## Wilder Amplification

93DMTX said:


> Yea, I'm sure I did something along those lines.
> 
> I was wrong earlier its Lead 1 that is mute. Lead 2 is present and accounted for and is phenomenal.



Yeah it would be Lead 1 if you jumpered R21 by mistake (more than likely you accidentally jumpered R21 instead of R20, which would ground out the gain pot when Lead 1 is selected).


----------



## Joey Voltage

Wilder Amplification said:


> Yeah it would be Lead 1 if you jumpered R21 by mistake (more than likely you accidentally jumpered R21 instead of R20, which would ground out the gain pot when Lead 1 is selected).



Oh lawrd! not the brown green yellow one! : the resistor is supposed to be purty yellow/purple/orange banded

this really does seems to bees an issue:laugh2


----------



## TwinACStacks

Tiny Print, Old eyes....

 TWIN


----------



## 6StringMoFo

Just an upload to let some of you hear what my amp sounds like after the Mercury Mag Superstack OT and PT TXs upgrade and choke(Thx to Jon for shipping them, we don't get cool shit out here on the Island)

[ame=http://www.youtube.com/watch?v=LHYohZ8XsUI]YouTube - solo.avi[/ame]

I've noticed the EQ'ing for Green Crunch and Red Lead 2 are almost identical. I've stopped using lead 1 when I play live for tone consistancy.

You have to turn it up to get the full effect since my amp was behind me to the left in the corner, it was a tragically hip song so I couldn't noodle too much.
I'm actually pretty happy with my lead tone. It's still real Marshall but think like a boston cream donut!! My reverb was actually pretty low, the room acoustics we're very fun.

Not sure if I'm going to mod it..


----------



## 93DMTX

Buggs.Crosby said:


> Sounds like you jumped r21 instead....a bunch of us have made that mistake



Yep, jumpered R21 right there in all it's glorious color...kinda embarressing...it ain't that hard to see.


----------



## 93DMTX

Allright, got lead 1 & 2 again and the tone is ALL there. I swear a couple little tweaks and for me this amp is now more than I had hoped for.

Thanks again guys for all the ground work and the help.

Oh, yeah, and after doing a little more reading in these parts I dropped the bias readings down to 73mV seems all good and mabye a little safer not pushing the limits.

Doug


----------



## 6StringMoFo

how does the bias affect the tone?

IE 

My bias is set to 80 mV and sounds like the DSL I know.

What tonal differences would occur with 90 mV?
What tonal differences would occur with 70 mV?


----------



## 6StringMoFo

93DMTX said:


> Allright, got lead 1 & 2 again and the tone is ALL there. I swear a couple little tweaks and for me this amp is now more than I had hoped for.
> 
> Thanks again guys for all the ground work and the help.
> 
> Oh, yeah, and after doing a little more reading in these parts I dropped the bias readings down to 73mV seems all good and mabye a little safer not pushing the limits.
> 
> Doug



93DMTX I would love to hear some clips of your DSL after the mods.


----------



## Buggs.Crosby

93DMTX said:


> Yep, jumpered R21 right there in all it's glorious color...kinda embarressing...it ain't that hard to see.



Common mistake that a few of us have made....me included



6StringMoFo said:


> how does the bias affect the tone?


i have a clip or two posted...but it was done with a shitty mic so it's hard to show off the tone but you can hear a difference...one is on page 7 (one page back) post 199....just a simple vid to show the gain changes on the green channel and how the crunch and lead 1 sound against each other


----------



## Buggs.Crosby

here is the ground bridge i did....ground comes right from the tranny and is soldered into the bridge....soon all tranny wires will be hardwired and i will lose those shitty W spade connectors....you dont have to go this far....all you need to do is link the 16ohm ground to the 4/8 next to it.....when you look at your board you will see that this is the only area there is no trace.....your going to make one


----------



## Buggs.Crosby

in fact you can see in that pic the traces that connect the middle four pins....but none on either end


----------



## Uncle Beef

ok so i have a quick question for you all. i have the jcm2 60-00 tube board in my 2000 dsl50. i just noticed at the beginning of the thread it says that these mods are for the 60-02 main board and the 61-00 pot board. will some of these mods still work on the 00 board? I'd really like to try to drop the c12 value on the main board as wilder described and see how it sounds. can i with this board?


----------



## Joey Voltage

Uncle Beef said:


> ok so i have a quick question for you all. i have the jcm2 60-00 tube board in my 2000 dsl50. i just noticed at the beginning of the thread it says that these mods are for the 60-02 main board and the 61-00 pot board. will some of these mods still work on the 00 board? I'd really like to try to drop the c12 value on the main board as wilder described and see how it sounds. can i with this board?



all mods are compatible, but you just have to take note the different part location numbers between boards. I thought Twin or JCM posted the conversion somewhere on this thread.


----------



## Buggs.Crosby

JCM has them on his site....there should be a link in Twins first post...i'll go check


----------



## Buggs.Crosby

It's there...just a little confusing...here you go
Marshall DSL


----------



## Buggs.Crosby

if you need any help with any of this stuff let me know....my head is in about 5 pieces so everything is easy to find and photograph if necessary


----------



## TwinACStacks

Buggs.Crosby said:


> if you need any help with any of this stuff let me know....my head is in about 5 pieces so everything is easy to find and photograph if necessary



 They Make drugs for that.

 DR. TWIN


----------



## Buggs.Crosby

TwinACStacks said:


> They Make drugs for that.
> 
> DR. TWIN



Yes....its called weed....a little can go a long way with me!


----------



## 93DMTX

Buggs.Crosby said:


> here is the ground bridge i did....ground comes right from the tranny and is soldered into the bridge....soon all tranny wires will be hardwired and i will lose those shitty W spade connectors....you dont have to go this far....all you need to do is link the 16ohm ground to the 4/8 next to it.....when you look at your board you will see that this is the only area there is no trace.....your going to make one



Thanks Buggs, that really does help a bunch. My next project.

Doug


----------



## TwinACStacks

You can also ground it on the jack casing bands without having to remove the board.

 TWIN


----------



## Buggs.Crosby

Yes....but i found it easier and better to use the already tinned posts.....only 7 nuts to pull that board ....then just flip it over


----------



## 93DMTX

TwinACStacks said:


> You can also ground it on the jack casing bands without having to remove the board.
> 
> TWIN



Thanks. Thats what I was initially thinking and trying visualize.

It will be a little more work but for me I the back of the board will turn out neater.

My big ol' 500W wood burning iron would probably melt the jacks.


----------



## Buggs.Crosby

93DMTX said:


> Thanks. Thats what I was initially thinking and trying visualize.
> 
> It will be a little more work but for me I the back of the board will turn out neater.
> 
> My big ol' 500W wood burning iron would probably melt the jacks.



Dont use a super hot iron....the traces on these things wont like the heat


----------



## Buggs.Crosby

And all this was not necessary but made tonight a little easier so far


----------



## Buggs.Crosby

take note in that pic the use of crayon dots to help mark the connections for faster assembly


----------



## 93DMTX

Buggs.Crosby said:


> Dont use a super hot iron....the traces on these things wont like the heat



Just kidding brotha...I use a Weller WTCP solder station.

Still good advice, I'd hate for anyone to mess up their DSL...now if it was a 6100...


----------



## 93DMTX

Alright, got the output grounds bridged. All is good.

Thanks again to all you guys that take the time to help others.


----------



## Buggs.Crosby

Just remember all 3 jacks are now active


----------



## Uncle Beef

Ok after struggling around for a bit with a blown OT and multiple wasted diodes my dsl 50 is working again. I replaced the OT with a mercury magnetics piece and its working great. Tone difference was VERY noticeable. I then went ahead and did the R12 mod mentioned in the first page to give my crunch channel some more umph and I really like that one as well. 

Kind of like Buggs said earlier though i'd like my green channel to be more of a pissed off whiskey drunk irishmen to steal his phrase. What else can i do to that crunch channel to liven it up a bit more?


----------



## solarburn

Uncle Beef said:


> Ok after struggling around for a bit with a blown OT and multiple wasted diodes my dsl 50 is working again. I replaced the OT with a mercury magnetics piece and its working great. Tone difference was VERY noticeable. I then went ahead and did the R12 mod mentioned in the first page to give my crunch channel some more umph and I really like that one as well.
> 
> Kind of like Buggs said earlier though i'd like my green channel to be more of a pissed off whiskey drunk irishmen to steal his phrase. What else can i do to that crunch channel to liven it up a bit more?



Step on it! That crunch channel was made for boosting. It can get as pissed off as you want it. Mine has been tweaked to have that low end flub gone when turned up without having to shape the EQ(decrease bass)between it and the other channels. I actually lost a bit of gain on it but man does it take pedals like a champ and still rolls off to clean and I don't have to worry about re eq'ing when I switch to Lead 2.

I know you're looking for a circuit tweak. I think a pedal here actually wins out. I base this on my taste and experience though.


----------



## 93DMTX

I'm with solarburn. I bought a TS9DX about 10 yrs ago to use with a Mesa Dual Caliber. Never liked it. Thought many times about just getting rid of it.

The DSL loves it though. The TS9 in front and a 10 Band EQ in the loop gave that little extra ooomph and control that allowed me to dial in exactly what I was after.


----------



## solarburn

93DMTX said:


> I'm with solarburn. I bought a TS9DX about 10 yrs ago to use with a Mesa Dual Caliber. Never liked it. Thought many times about just getting rid of it.
> 
> The DSL loves it though. The TS9 in front and a 10 Band EQ in the loop gave that little extra ooomph and control that allowed me to dial in exactly what I was after.



Haha. I've got both too. Right now I'm using the 10 band in front right after the Boosta Grande clean boost and delay in the loop. Fuck'n tools of the trade man!LOL

DSL's are clean boost/OD pedal friendly period. If you can do mods yourself than that's just another plus at getting what you want out of it.


----------



## Uncle Beef

Thats what I've been doing since i got it. I have it setup now where I use my greedtone overdrive which i think blows away any tubesreamer ive ever heard. I never use the clean channel but i like the crunch a lot. I have it set at about 3 or so on the gain and 9 on the volume. God I love power tube distortion. 

But I am looking to get rid of that low end flub and tighten it up a bit as well. Next mod to be done.

How do you like that 10 band eq? I was looking at some the other day.


----------



## jcmjmp

Uncle Beef said:


> But I am looking to get rid of that low end flub and tighten it up a bit as well. Next mod to be done.



The V1a cathode cap should help with that but first... 

1) how is the amp biased? I recommend 65%
2) What kind of EL34s? I recommend SED =C=
3) What kind of speakers?
4) What settings on the amp to reproduce this "flub"?


----------



## solarburn

Uncle Beef said:


> Thats what I've been doing since i got it. I have it setup now where I use my greedtone overdrive which i think blows away any tubesreamer ive ever heard. I never use the clean channel but i like the crunch a lot. I have it set at about 3 or so on the gain and 9 on the volume. God I love power tube distortion.
> 
> But I am looking to get rid of that low end flub and tighten it up a bit as well. Next mod to be done.
> 
> How do you like that 10 band eq? I was looking at some the other day.



Wilder got rid of that flub on mine. Whatever the hell he did its gone. Its more plexi like but not a plexi hehe. I keep the gain on it all the way up and it just hits ACDC territory. Early ACDC at that. So when I hit it with a boost or OD it crunches up like crazy and the neck pu on the strat...sultry with a bit of woman heat on it. You know the kind that makes you go slow & deep. Fuck I need a cig... 

I can even run lead 2 close to full out on the gain at volume with the deep switch in. He's made it so the gain doesn't come in too fast and overbearing but remains tight too. 

Usually I use EQ pedals as a boost in the loop but I tried it in front end and found it works very good with certain parameters adjusted. So I really like it now since it can go both in the front end and in the loop. It really can help alleviate flub in lows and razor highs and push any mids needed. I'm using the MXR. I think its a great addition to mods to have at your disposal.


----------



## Buggs.Crosby

My drunken Irishman may not be a mod you want....for one your clean will all but disappear
that is your clean will sound like your crunch does now.....your Valves will also take a small life expectancy hit. they also require a good disassembley of the amp....not sure how far you have gone or have a clues as to your skill level either....the one part of the mod is listed in the thread and is easy to do....it wont get you a pissed off Irishman....but it will give some more gain


----------



## Joey Voltage

Buggs.Crosby said:


> .your Valves will also take a small life expectancy hit. they also require o good disassembley of the amp



Nah, that mod wont do shit to valve life expectancy


----------



## Joey Voltage

Uncle Beef said:


> Thats what I've been doing since i got it. I have it setup now where I use my greedtone overdrive which i think blows away any tubesreamer ive ever heard. I never use the clean channel but i like the crunch a lot. I have it set at about 3 or so on the gain and 9 on the volume. God I love power tube distortion.
> 
> But I am looking to get rid of that low end flub and tighten it up a bit as well. Next mod to be done.
> 
> How do you like that 10 band eq? I was looking at some the other day.



the first page has mods to do that. the first step you already did - c12, but easily done with just one extra component swap on either green or red.


----------



## Buggs.Crosby

Joey Voltage said:


> Nah, that mod wont do shit to valve life expectancy



is that your way of saying i could push it more?.....LOL


----------



## Joey Voltage

Buggs.Crosby said:


> is that your way of saying i could push it more?.....LOL



If you really wanted to, although at some point it might be unusable


----------



## TwinACStacks

Christ Buggs, why don't you just get an ENGL or one of those Mojave BAD BOYS? Marshalls aren't supposed to have THAT much gain, something Bad might happen, like a rip in the space/time continuum or WORSE.

Come to think of it, that Oil spill in the Gulf started right about the time you finished your Mods.....

 TWIN


----------



## longfxukxnhair

TwinACStacks said:


> Christ Buggs, why don't you just get an ENGL or one of those Mojave BAD BOYS? Marshalls aren't supposed to have THAT much gain, something Bad might happen, like a rip in the space/time continuum or WORSE.
> 
> Come to think of it, that Oil spill in the Gulf started right about the time you finished your Mods.....
> 
> TWIN



He is getting that DSHell to the point it can flambe


----------



## Buggs.Crosby

TwinACStacks said:


> Christ Buggs, why don't you just get an ENGL or one of those Mojave BAD BOYS? Marshalls aren't supposed to have THAT much gain, something Bad might happen, like a rip in the space/time continuum or WORSE.
> 
> Come to think of it, that Oil spill in the Gulf started right about the time you finished your Mods.....
> 
> TWIN



Nice try....BP had nothing to do with my amp......now our two J techs are a different story

and LH....My DSHell already Flambe's your 6100.....back to the Darkside with you


----------



## Uncle Beef

jcmjmp said:


> The V1a cathode cap should help with that but first...
> 
> 1) how is the amp biased? I recommend 65%
> 2) What kind of EL34s? I recommend SED =C=
> 3) What kind of speakers?
> 4) What settings on the amp to reproduce this "flub"?



1. Have to bring home my multimeter ill get back to you on the bias. 
2. el34 are jj's
3. speakers are 1960 cab so Celestions if im not mistaken
4. as far as setting go my music tends to be on the bassier side and its what I write. however i need it to be a tight bass. current settings are 7 on the treble, 5 on the mids, 8 on the bass. deep switch out, tone shift switch out as well. Ive found for the music I write that its as tight as its going to get but its still too loose for my taste.


----------



## Buggs.Crosby

Beef a choke will help tighten the low end up


----------



## TwinACStacks

Beef Did You change out your Grid Blockers to 5K6?

 TWIN


----------



## Buggs.Crosby

TwinACStacks said:


> Beef Did You change out your Grid Blockers to 5K6?
> 
> TWIN


should not be an issue on a 2005 model i thought?
what MM tranny did you get?


----------



## Jack92CH

Is there a way to get the Deep and Mid-scoop switches adjustable with a pot? I don't use the reverb at all and figured I'd do something cool with two knobs that never get used. Are there specific components that can be wired into a pot? It would be sweet to have a range of mids and extra bass response.


----------



## Wilder Amplification

Jack92CH said:


> Is there a way to get the Deep and Mid-scoop switches adjustable with a pot? I don't use the reverb at all and figured I'd do something cool with two knobs that never get used. Are there specific components that can be wired into a pot? It would be sweet to have a range of mids and extra bass response.



The Deep yes. The mid scoop/tone shift no. There's 3 poles worth of switching going on with the tone shift circuit so this would be near impossible.

With the Deep circuit, you remove R43 on the pot board and replace it with a 10K pot.


----------



## Joey Voltage

Jack92CH said:


> Is there a way to get the Deep and Mid-scoop switches adjustable with a pot? I don't use the reverb at all and figured I'd do something cool with two knobs that never get used. Are there specific components that can be wired into a pot? It would be sweet to have a range of mids and extra bass response.



*Absolutely *yes to both!


----------



## jcmjmp

Joey Voltage said:


> *Absolutely *yes to both!



Additionally, if you (Jack92ch) read through the posts (or search) in this thread, you'll find info on how to modify either one. Adding a pot is easy once you know which components need to change. The mid cut is a single component change and the deep can also be altered with a single component.


----------



## Jack92CH

Is there somebody here who has already done this? I'd just use the two reverb pots to adjust each one if I could hook them up. I like the idea of the deep and mid-scoop switches, I'd just rather be able to adjust the levels of each one instead of having them be either on or off.


----------



## tweed

Just wanted to take a minute and thank everyone for the help and contributing to this thread. It is Great!!

I changed out R12 on the input board this morning to 100k to see if I would like the change, it sounds pretty good, but the amp is still not doing it for me. So I think its time to move on and try another flavor. Anyone know what the going price for a dsl50 w/choke, footswitch, =C= power tubes, 2 tung's in V1/2, GT V3, and sovtek LPS V4 would be?

Thanks in advance!


----------



## Joey Voltage

Jack92CH said:


> Is there somebody here who has already done this? I'd just use the two reverb pots to adjust each one if I could hook them up. I like the idea of the deep and mid-scoop switches, I'd just rather be able to adjust the levels of each one instead of having them be either on or off.



you can use one of the reverb controls for the depth,butyou would need an aftermarket pot fo the other,and there are three easy ways you can go about it, with the "shift" there are also other ways to use unconventional mods to acheive this, but this is beyond this sections intent. you can do pretty much anything you want to, so long as you put your brain to it


----------



## Jack92CH

Why would I need an aftermarket pot if there's already an extra after the depth pot is hooked up? I'm thinking I'll just make this a separate thread to see if anyone has done the same thing.


----------



## Wilder Amplification

Jack92CH said:


> Why would I need an aftermarket pot if there's already an extra after the depth pot is hooked up? I'm thinking I'll just make this a separate thread to see if anyone has done the same thing.



More than likely because the pot needed to do this is a different value than the pot that's left over.



Joey Voltage said:


> you can do pretty much anything you want to, so long as you put your brain to it



Yes we know this. However, while some things CAN be done this doesn't mean that there's a "practical" way to pull it off. Just like the "passive effects loop" that's really just a "Preamp Out/Power Amp In". Yes it's possible to make that work...however, is the method required to make it work very practical? Not by any means...and is why it's best to use an active loop circuit that resides pre-master.

On top of this, while anything's possible if you "put your brain to it", most of the people here don't have the electronics background that we do and lots have made that either clearly evident or have openly admitted it. Without some sort of base knowledge of electronics, filter circuits, etc etc...what's anyone gonna put their brain to? They wouldn't even know where to start!


----------



## Buggs.Crosby

Jack92CH said:


> Is there somebody here who has already done this?



Yes i have that mod now....still 1 pot for both channels...but i am working on indapendants for each when channel changing... pm me so as not to clog the thread and i'll give you the info and give the techs a break....unless they want to continue on this one....your call guys....just the deep pot....not the mid
what i have came from Jon and is only active with the deep out....in it is fully active as before


----------



## solarburn

Wilder Amplification said:


> More than likely because the pot needed to do this is a different value than the pot that's left over.
> 
> 
> 
> Yes we know this. However, while some things CAN be done this doesn't mean that there's a "practical" way to pull it off. Just like the "passive effects loop" that's really just a "Preamp Out/Power Amp In". Yes it's possible to make that work...however, is the method required to make it work very practical? Not by any means...and is why it's best to use an active loop circuit that resides pre-master.
> 
> On top of this, while anything's possible if you "put your brain to it", most of the people here don't have the electronics background that we do and lots have made that either clearly evident or have openly admitted it. Without some sort of base knowledge of electronics, filter circuits, etc etc...what's anyone gonna put their brain to? They wouldn't even know where to start!



Hey I resemble this remark...:eek2:


----------



## Buggs.Crosby

+2.....i know a little.....but a whole lot less than what i learned


----------



## Joey Voltage

Wilder Amplification said:


> .and is why it's best to use an active loop circuit that resides pre-master.



This is not always the best way no matter how much you advocate this!, and will NOT work with some equally as good loops on the market, in fact some premaster loops are quite bad for that reason, did you think about situations where you wouldn't want that????? anyway this has absolutely nothing to do with the question posed, and I'm done fighting you on your convictions, and I'm done playing pickup after you shoot down a proposition with "no it can't be done". Next time you say _no it can't be done_, I wont be the one challenging it.

If practical is the big question, how is a single aftermarket pot impractical? answer me that? I can think of three different ways to employ what the poster asked with just one pot, thats right just one, and some elbow grease. 



Wilder Amplification said:


> On top of this, while anything's possible if you "put your brain to it", most of the people here don't have the electronics background that we do and lots have made that either clearly evident or have openly admitted it. Without some sort of base knowledge of electronics, filter circuits, etc etc...what's anyone gonna put their brain to? They wouldn't even know where to start!



sorry, I don't *Publicly* hand out free mods anymore

comment was meant to inspire the individual, maybe a potential aspiring DIY'er for all I know, maybe to evoke questions (I don't just hand things out anymore and say there you go), or maybe he wants to ask for links where he can better learn about this stuff, or maybe ask where he can join a DIY orientated BBS....... or maybe to inspire the ideas amongst any of you to put forth. JCMJMP seemed to have an idea he was willing to put out in the public. To be fair, I have already put in loads of timein this section.


Like I said before, If somebody wants to ask me specific questions, or for help via PM, that is the best way to get a hold of me. After tonight, I will most likely not read a post in any one of the sections until it is already 3 or 4 pages back. My time is very limited here for now!!!


----------



## TwinACStacks

Popcorn's good. Anybody got some salt?

 TWIN


----------



## Uncle Beef

TwinACStacks said:


> Beef Did You change out your Grid Blockers to 5K6?
> 
> TWIN



Grid Blockers???? Limited electronics experience. Learning as I go. I'll look at my schematic for my amp but no I didnt change out any grid blockers. What board are they on?



Buggs.Crosby said:


> should not be an issue on a 2005 model i thought?
> what MM tranny did you get?



Buggs I dropped in the Mar50-0 OT. American Pro Series. Dig the hell out of it so far. Just has a little bit more of everything ya know?

Also aside from that I just want to thank everyone for all the help that this thread has provided you guys kick ass.


----------



## solarburn

TwinACStacks said:


> Popcorn's good. Anybody got some salt?
> 
> TWIN



We need Joey and Jon to have their own tech thread regarding "tech help" stuff so they don't have to be on the same threads together. That way people could choose who they want and keep all the cross talk between each other out of the way. The other techs seem to be fine where ever they are hehe. Non issue for them.

Just a thought and I would use either of them. Both are awesome.


----------



## Buggs.Crosby

Beef your grid blockers are R7, R10, R66, R70.....early issues came with 220k.....later models (your's included) should be corrected to the more normal 5.6k and they are on the tube board
what issue number is your board?


----------



## 6StringMoFo

How does one..

Mod it for a more open sounds with more sustain?

Sometimes it feels like my sound is getting choked.. if that makes any sense


----------



## Buggs.Crosby

can you define open and sustainy a little better?.....not enough mids and highs?
post a recorded example of what your looking for (David Gilmour,...Jimmy Page...Eddi Van Ailing)...................the mod you want is most likely posted.....we just have to figure out where you want to go


----------



## jcmjmp

6StringMoFo said:


> How does one..
> 
> Mod it for a more open sounds with more sustain?
> 
> Sometimes it feels like my sound is getting choked.. if that makes any sense



Maybe you should install a choke to unchoke it.


----------



## 6StringMoFo

jcmjmp said:


> Maybe you should install a choke to unchoke it.



I did install a choke. JUst feels like my notes are getting squeezed sometimes. Of course the louder i play it the less "choked" it sounds


----------



## Buggs.Crosby

what mode?.... do you mean brighter?......what are your settings?....based off of those what do you feel you need?.....tighter or loser bottom?...more or less mids?......harmonic content?...there are a ton of ways you can go but you kinda have to be more specific to what you are trying to get at


----------



## TwinACStacks

He wants it ALL....

 TWIN


----------



## Buggs.Crosby

here are the next mods on my DSL
1. the stock loop is being removed and replaced with a Miller loop and relocated before the master volumes where it should have been located in the first place
it will be two full channels with 5 modes total.....ultra will stay the same.....the first channel..... will be clean.....plexi and hot rodded 800
each channel will have the deep pot instead of a switch
there will be the sag/tight switch added
all gain channels will have foot switchable a solo boost
and it will look similar to this mock up


----------



## jcmjmp

Buggs.Crosby said:


> here are the next mods on my DSL
> 1. the stock loop is being removed and replaced with a Miller loop and relocated before the master volumes where it should have been located in the first place
> it will be two full channels with 5 modes total.....ultra will stay the same.....the first channel..... will be clean.....plexi and hot rodded 800
> each channel will have the deep pot instead of a switch
> there will be the sag/tight switch added
> all gain channels will have foot switchable a solo boost
> and it will look similar to this mock up



Are you serious? Why not just build from scratch. Seems like a lot of hassle to mod it to that.


----------



## Buggs.Crosby

it's not as bad as it seems really....the hardest part will be making the switching and low voltage board......everything else will almost clip right in as it does now....just in different locations....i will build something in the future as i learn more......something this project will help me with
basically i'm turning it into the amp it should have been from the start


----------



## Buggs.Crosby

besides......didnt you post that you were gonna make a point to point board for one of these?..................thats just as crazy as what i'm doing


----------



## jcmjmp

Buggs.Crosby said:


> besides......didnt you post that you were gonna make a point to point board for one of these?..................thats just as crazy as what i'm doing



Haha. Not really. the PTP board will just drop in and gets rid of the annoying PCB mount tube sockets. Parts of it will be PCb though.


----------



## Buggs.Crosby

jcmjmp said:


> Haha. Not really. the PTP board will just drop in and gets rid of the annoying PCB mount tube sockets. Parts of it will be PCb though.



well get on it....as soon as i see it work i'll do one.....the only thing left in my Marshall at that point would be the box....LOL.......i say this because the rear board is also also no longer


----------



## Joey Voltage

jcmjmp said:


> Haha. Not really. the PTP board will just drop in and gets rid of the annoying PCB mount tube sockets. Parts of it will be PCb though.



you can thin some stuff out as well. You could just build a goddamned SLO out of it at that point, or just adapt the PTP slo board to your needs


----------



## jcmjmp

Joey Voltage said:


> you can thin some stuff out as well. You could just build a goddamned SLO out of it at that point, or just adapt the PTP slo board to your needs



My biggest problem right now is time and a broken DSL I can salvage to get the PTP board project going.


----------



## Buggs.Crosby

why does it have to be broken?


----------



## TwinACStacks

Buggs.Crosby said:


> here are the next mods on my DSL
> 1. the stock loop is being removed and replaced with a Miller loop and relocated before the master volumes where it should have been located in the first place
> it will be two full channels with 5 modes total.....ultra will stay the same.....the first channel..... will be clean.....plexi and hot rodded 800
> each channel will have the deep pot instead of a switch
> there will be the sag/tight switch added
> all gain channels will have foot switchable a solo boost
> and it will look similar to this mock up



Hey Look!!! Buggs just built a Better JVM....

 TWIN


----------



## jcmjmp

Buggs.Crosby said:


> why does it have to be broken?



I don't want to pay for a working amp, just to rip out the tube board out of it.


----------



## Buggs.Crosby

jcmjmp said:


> I don't want to pay for a working amp, just to rip out the tube board out of it.



what do you need from it?


----------



## jcmjmp

Buggs.Crosby said:


> what do you need from it?



I need the chassis, power supply board and the front & read boards. 
PT/OT, head case, reverb board and reverb spring are all optional.


----------



## 93DMTX

Any one got any tips or advice on the easiest/best way to get the main bd out of a DSL100. I've been wanting to try some of the main bd mods but have been putting it off because it looked like a bitch to get it out (ok, maybe the bitch wouldn't be getting it out so much as getting it back in right).

Wanting to hit C9, C12 and check for and remove C46. Already piggy backed R30 from above.

Thanks greatly!!


----------



## rjohns1

93DMTX said:


> Any one got any tips or advice on the easiest/best way to get the main bd out of a DSL100. I've been wanting to try some of the main bd mods but have been putting it off because it looked like a bitch to get it out (ok, maybe the bitch wouldn't be getting it out so much as getting it back in right).
> 
> Wanting to hit C9, C12 and check for and remove C46. Already piggy backed R30 from above.
> 
> Thanks greatly!!



Take pictures, and mark all of the wires, as to which locations they go. Each wire you take off, take a picture, that way, if you forget where it goes, you can reference the pictures to remember how to hook it back up. When I had my DSL, it took me about 20 minutes to get it out, but I had to resort to asking guys for pictures the first time because I couldn't remember where the wires went. Not hard, just takes a little time. be patient, and you will be able to do it. Discharge those caps first!!!!!!!!!!!!!!! If you don't know what that means, stop and leave it alone!


----------



## Buggs.Crosby

when i complete this pdf you will no longer need any help....it will all be right there....and when you need more info just click........i hope to have it done soon....i almost have the pot board done and the rear board is a joke in comparison....the main board will be hard because of it's size


----------



## 93DMTX

Buggs, that sounds like a great project to help the DSL bretheren.

Was thinking that maybe I needed to pull the rear board to get the tube board out but now after I got the chassis back out it looks like the tube board best comes out from the top with the cover/power tube socket support.

Rjohns1, you ain't kiddin'...digital cameras are the best for this kinda stuff.


----------



## Buggs.Crosby

dont worry if you mess up and cant figure out what goes where just ask


----------



## MartyStrat54

Are you going to include the 401 boards, or just the 50 and 100?


----------



## Buggs.Crosby

for now just the 50 and 100....i would need good pics of the boards for the 401 and 201
know anyone with one disassembled?


----------



## 93DMTX

Alrighty, C9/12 main Bd done. Just removed C46. This is an iss10 bd.

Worst part was thinking about all those cables...doing it wsn't bad!

I like it! Tanks for the help! Actually work first time back together.


----------



## Buggs.Crosby

you want to be careful on those W spade connectors....they suck and break easy which is why i am going hardwired


----------



## Buggs.Crosby

did you do the rear jack mod while you were in there?


----------



## 93DMTX

Buggs.Crosby said:


> you want to be careful on those W spade connectors....they suck and break easy which is why i am going hardwired



I agree on those shitty things. Once I'm sure I got it where want it I might think about hardwire too.

That sure would take the amount of work getting the bd out to a whole other level wouldn't it?


----------



## Buggs.Crosby

for you and your board yes.....that why i'm getting rid of my rear board all together


----------



## 93DMTX

Buggs.Crosby said:


> did you do the rear jack mod while you were in there?



I did the output jacks ground bus wire one early on.


----------



## Buggs.Crosby

smart move


----------



## 93DMTX

Has anybody thought about adding a PPIMV to a DSL?

~or~ Is that a dumbass question for some reason I don't yet fathom and was asked purely out of my -> .


----------



## Joey Voltage

93DMTX said:


> Has anybody thought about adding a PPIMV to a DSL?
> 
> ~or~ Is that a dumbass question for some reason I don't yet fathom and was asked purely out of my -> .



Depends on what type of music you like. The purpose of _most_ high powered, modern high gain amps such as the DSL is to produce 99.9% of the overdrive/distortion, and tone shaping in the preamp, and then rely on the PA to amplify it with only subtle coloring.

a PPIMV will allow you to over drive the phase inverter more heavily as well (amongst other things) which will lead to a whole different set of nuances you may or may not like. To heavily generalize, If you are a heavy metal player/harder rock player, and want a more stringent overdrive, a PPIMV may not be the order of the day. however if you are a bluesier player, and like a more smeared/creamy overdrive characteristic, you might like it very much. again these descriptions are not set in stone, you can work anything to your benefit, it just takes some insight, and depends on whether or the trouble justifies the means, or whether the end result just equate to a more elaborate way of getting what you originally had......... again this is all a gross generalization.


----------



## tweed

Well looks like my DSL is sticking around for a bit so I placed an order with Mouser yesterday. Gonna take a stab at some mods, mostly the Fortin stuff, and see how it turns out. 

I'm excited to get back in there and change things. All I have done so far is grounding the speaker jacks and swapping R12 on the input board to 100k. Installed a choke when I first got the amp so that's one less thing to do...


----------



## 93DMTX

I'm thinking that my first shot will be with something like the attached. All attaching can be done at the removed R4/R5 links.

I'll just carefully hang the pot out with shielded cable until I decide if I want to make it permanent.


----------



## 93DMTX

Getting ready to try the first version of a PPIMV.

Interestingly this unused location for CON12 will be the perfect place to locate the cables out to the dual pot after removing the two links R4/5.

This board sure looks to me like there was some thought about a PPIMV in its design layout.


----------



## Buggs.Crosby

the only schem that even shows that Conn has it marked as Conn 9....but is does not say where it should go...it also labels the links as r47 and r48 as what looks to be 680k resistors.....i have the pot and rear boars plotted but i still have to do the tube board


----------



## Buggs.Crosby

do me a favor....look on your pot board for C9....does it exist?....same thing for r14


----------



## 93DMTX

Buggs.Crosby said:


> the only schem that even shows that Conn has it marked as Conn 9....but is does not say where it should go...it also labels the links as r47 and r48 as what looks to be 680k resistors.....i have the pot and rear boars plotted but i still have to do the tube board



This bd is an iss10 and it seems to sorta match my iss7 schematic.




Buggs.Crosby said:


> do me a favor....look on your pot board for C9....does it exist?....same thing for r14



My pot bd is an iss5

C9 is NOT loaded
R14 seems to be loaded but markings not clear

here's a pic of the area,


----------



## 93DMTX

Well, its done and works the way it should.

Jury is still out on whether or not it gets a permanent home.

Cheap ass radioshack pot will get replace if it gets made permanent.


----------



## Buggs.Crosby

93DMTX said:


> This bd is an iss10 and it seems to sorta match my iss7 schematic.
> 
> 
> 
> 
> My pot bd is an iss5
> 
> C9 is NOT loaded
> R14 seems to be loaded but markings not clear
> 
> here's a pic of the area,



i bet if you look close enough r14 is a 22u cap.....and no C9.....this is one of the few oddballs i have found when creating the loading chart.....more will follow


----------



## Buggs.Crosby

sorry the pics are so big....i'll resize them


----------



## Micky

No D3 or C12 either...


----------



## 93DMTX

Micky said:


> No D3 or C12 either...



C12 was originally loaded. Lowering the value or removing is a mod to darken OD 1/2.


----------



## Buggs.Crosby

on the only pot board schems i have (issue 1 50 watt courtesy of JCM's site and issue 1 100 watt) are at odds......the 50 watt version shows D3 to be a 1n4007 while the 100 watt shows it to have the 22u 25v cap that we have in R14......there are definitely either more schems out there or this is an unmarked change that will now be marked


----------



## 93DMTX

I've got a JCM2-61-00 iss5 schematic.

I think it came from dr tube. The link seems to be labeled wrong. Labeled 61-02 iss5 but schem is actually a 61-00 iss5.

http://www.drtube.com/schematics/marshall/jcm2-61-02.pdf


----------



## Buggs.Crosby

how did i not have that one....i think i did but must have deleted it by accident....on that it shows D3 not fitted......but it still shows the cap in it's place......the issue 1 board shows it to be a 10k.....


----------



## tweed

here's a silly question. I am venturing back in to the amp soon for some mods and I remember last time, even with photos, I managed to cross a few "con" connections from the input board and the main board. Is there a document somewhere that has all of these ribbon connections listed? Sort of like a re assembly checklist for dumb asses like myself?


----------



## 93DMTX

tweed said:


> here's a silly question. I am venturing back in to the amp soon for some mods and I remember last time, even with photos, I managed to cross a few "con" connections from the input board and the main board. Is there a document somewhere that has all of these ribbon connections listed? Sort of like a re assembly checklist for dumb asses like myself?



Man, the tube board is the worst.

First time I pulled it I wrote down each connection - source and destination - as I disconnected and took digital pics.

I only disconnect at the bd I'm removing. And of course never pull the cables.

Then I reversed back through my list to reinstall. Made it very easy to re-install. Now maybe 10 minutes to fully reinstall.


----------



## tweed

Thanks, i'll give that a shot tonight or tomorrow, just didn't want to recreate the wheel if I didn't need to .

I know the other thing I need to do is verify the version of my main board. On the input board it was pretty easy, found the issue section and one number the square was filled in so I take it that is the issue number. On my main board I found the section but none of the squares are filled completely, just list numbers 6 7 8 9 10. Do I assume this is an issue 5 board? 

I should have brought the pictures with me to work today and wrote this info down, but I was in a bit of a hurry getting out the door this morning...


----------



## 93DMTX

Hey Buggs, you gonna do any kinda of stuff like dis-assembly / re-assembly guides with what your working on?

Anyway, if you are I might could help contribute.

Might even be cool to grow it nto DSL wiki.


----------



## Buggs.Crosby

tweed said:


> Thanks, i'll give that a shot tonight or tomorrow, just didn't want to recreate the wheel if I didn't need to .
> 
> I know the other thing I need to do is verify the version of my main board. On the input board it was pretty easy, found the issue section and one number the square was filled in so I take it that is the issue number. On my main board I found the section but none of the squares are filled completely, just list numbers 6 7 8 9 10. Do I assume this is an issue 5 board?
> 
> I should have brought the pictures with me to work today and wrote this info down, but I was in a bit of a hurry getting out the door this morning...



that would seem a bit odd.....at least one number should be whited out like on pot board......i definitely have an issue 5 tube board but is not laid out like that......do get the pics up when you can


----------



## Buggs.Crosby

93DMTX said:


> Hey Buggs, you gonna do any kinda of stuff like dis-assembly / re-assembly guides with what your working on?
> 
> Anyway, if you are I might could help contribute.
> 
> Might even be cool to grow it nto DSL wiki.




it wont necessarily be a guide.....but it is laid out so every component is marked
with all necessary info in pop up form.....its not even close to being done
i would post a sample but is already to large for the forum to host it


----------



## Buggs.Crosby

93DMTX said:


> Might even be cool to grow it nto DSL wiki.



shall i ad trace x-rays to it ?


----------



## 93DMTX

Buggs.Crosby said:


> shall i ad trace x-rays to it ?



Cool, and some 6100 jokes too.


----------



## 93DMTX

Back to my PPIMV...

So I've decided I like it but not enough (yet) to drill a new hole.

I think I got room to remove the Chan B reverb pot and stick it there.

Who F'ng needs reverb on B anyway.


----------



## tweed

I usually keep the reverb on zero (both channels) and leave a DD3 on in the loop. : )


----------



## Buggs.Crosby

i've revised a few schematics to remove the reverb and or loop completely


----------



## Buggs.Crosby

here is the rear board with no loop or reverb

thats funny it did not attach


it will work this time


----------



## Buggs.Crosby

my whole rear board is gone....the low power section is going on it's own small board
the loop is getting replaced with one Jons loops.....the output jacks will be hard wired to 4/8/16 ohm jacks and the reverb jack so far will be a solo boost


----------



## 93DMTX

Dude, thats some major surgery...call you DR. DSHell


----------



## tweed

Buggs.Crosby said:


> my whole rear board is gone....the low power section is going on it's own small board
> the loop is getting replaced with one Jons loops.....the output jacks will be hard wired to 4/8/16 ohm jacks and the reverb jack so far will be a solo boost



Whoa 

A solo boost sounds interesting. How hard was that to incorporate?


----------



## Buggs.Crosby

look at the picture in my avatar....by the end of the year thats what the DSHell will look like


----------



## 93DMTX

Alright, the Post PI Master is in it's home. Think I'm definitely stuck with the mini dual pot if I leave it here.

I'm still kinda hesitant to do any mods that are not fully reversible - like drilling chassis holes.


----------



## Buggs.Crosby

you gonna give us a run down on it?....so far the only thing you said was you are not sure if you like it......but there were no FUCKING details.....................


----------



## tweed

sweet! Give us the low down on the PPIMV!


----------



## 93DMTX

Buggs.Crosby said:


> you gonna give us a run down on it?....so far the only thing you said was you are not sure if you like it......but there were no FUCKING details.....................



yeah, yeah, yeah...

... i gives ya the schematic, i shows ya where and how i'm gonna connect it and i shows ya where i mounted it...

...now, its gonna take me a day or two to decide sonically. I'm gonna try a few different PI's. One thing I already like about it is it tames the fx return. You ever accidentally hit the return with a BIG fat signal?

More ta come, i promise...


----------



## Buggs.Crosby

i can see and do all that....i meant sound wise...pro's/con's


----------



## MM54

Buggs.Crosby said:


> it wont necessarily be a guide.....but it is laid out so every component is marked
> with all necessary info in pop up form.....its not even close to being done
> i would post a sample but is already to large for the forum to host it



I have a server with 2TB disk and 15TB monthly bandwith, if you want somewhere to host it let me know, I can do it free, no problem


----------



## Buggs.Crosby

its no where near that large....but it is to big to attach now and it has a good bit to go
my one question would be access for editing updates


----------



## MM54

I'll put it in its own folder and give you an FTP account with access to that folder if you want, then it can be on a subdomain or it's real directory from root.


----------



## tweed

Buggs.Crosby said:


> that would seem a bit odd.....at least one number should be whited out like on pot board......i definitely have an issue 5 tube board but is not laid out like that......do get the pics up when you can



Here's a link to a bunch of gut shots of my DSL 50. The last 5 or so you can see the issue numbers on the boards and can see the shot with the main board and the numbers not whited out.

boards pictures by mctweed - Photobucket


----------



## Micky

WTF with all the ads on PhotoBucket?
I didn't get to see the shots you took - Too many ads popping up everywhere.
Blocker wouldn't stop it!
I ain't never goin back there...


----------



## tweed

Micky said:


> WTF with all the ads on PhotoBucket?
> I didn't get to see the shots you took - Too many ads popping up everywhere.
> Blocker wouldn't stop it!
> I ain't never goin back there...



i have no idea whats up with the ads. I'll try and post the pics in this thread now that they are online...

In this one you can see the input board and rear board issue numbers plainly.







Here is the mainboard and as you can see starts with 6 in the issue portion and no numbers are whited out






No issue numbers should make things fun lol. I have all 3 boards out on my bench at home and I'm diving in this weekend. I am hoping to get this completed by Monday so I can take it to rehearsal and try it in a band context.


----------



## jcmjmp

tweed said:


> Here is the mainboard and as you can see starts with 6 in the issue portion and no numbers are whited out
> 
> No issue numbers should make things fun lol. I have all 3 boards out on my bench at home and I'm diving in this weekend. I am hoping to get this completed by Monday so I can take it to rehearsal and try it in a band context.



That means its an Issue 6 board.


----------



## tweed

jcmjmp said:


> That means its an Issue 6 board.



Thanks for the clarification!


----------



## Buggs.Crosby

i have a bunch more schems but i dont have that tube board....but it cant be much different than issue 5 and issue 7....i have the rest


----------



## Buggs.Crosby

actually i see quite a few changes....nothing to great effect though


----------



## 93DMTX

jcmjmp said:


> That means its an Issue 6 board.



This is kinda wierd...

The issue 7 (DSL100) schematic has a revision date of 2-8-01.

Can see from tweed's pic his amp is M-2004-36.

Almost like they stopped updating the marking on the tube board at some point.


----------



## Buggs.Crosby

every board schem i have is dated 97


----------



## 93DMTX

Buggs.Crosby said:


> every board schem i have is dated 97



Buggs, check the left hand bottom corner. Should show the iss date.


----------



## Buggs.Crosby

issue 5 was last revised in 98


----------



## Buggs.Crosby

93DMTX said:


> Buggs, check the left hand bottom corner. Should show the iss date.



just got to them


----------



## Buggs.Crosby

you and tweed have the same tube board...and i'll bet the same pot board as well


----------



## tweed

It won't be the same for long ; )


----------



## Buggs.Crosby

LOL....what do you plan on getting into?


----------



## tweed

Going to do the Fortin mods this weekend.


----------



## Buggs.Crosby

did you do the output jack yet?.....if not make it the first one


----------



## tweed

I did a quick job on the output jacks, tied a wire from w6 to the jacks and had to de solder this morning to get the rear board out. I'm sure there is a better way to do it.


----------



## Buggs.Crosby

thats one of the reasons i am getting rid of the rear board all together...other than the low power section i dont need it and i dont trust the spade connectors


----------



## Buggs.Crosby

i may need another pic or two but based off of what you have i will make a connections chart for you.....wanna know where Conn 3 goes?....just scroll over it and it will tell you


----------



## tweed

Buggs.Crosby said:


> i may need another pic or two but based off of what you have i will make a connections chart for you.....wanna know where Conn 3 goes?....just scroll over it and it will tell you



I would love to have that! I scratched everything down on paper this morning, well I hope I got everything, and typed it into word. I can paste it here if it will help. 

Only thing I may need some serious help with is reattaching the leads from the transformer. There were 2 purple and 3 blue leads, I tried to keep them in order and wrapped blue tape around them hoping to keep them in line. Didn't have time to snip all the zipties and trace them out one by one.


----------



## Buggs.Crosby

can you post a pic?....this is definitely different from my head....im assuming you mean w9.....w10....w11 and w12 and w13


----------



## Buggs.Crosby

email me what you have so far....i'll send a sample in return so you can see what it will be like buggs.crosby@yahoo.com


----------



## jcmjmp

Buggs.Crosby said:


> every board schem i have is dated 97



Look at the revs. The date codes show each incremental change. At the bottom of the schems.


----------



## tweed

email sent...

here's a pic, far right hand side you'll see the connections I was talking about


----------



## Buggs.Crosby

yeah...they just changed the wire colors from what i can see in that pic.....no fear colors will no matter.....


----------



## Buggs.Crosby

is there any reason F4 does not exist in its holder?


----------



## Buggs.Crosby

never mind you have the 50 watter....but i do wonder why it was loaded on the board and what else is there for the 100 watter


----------



## tweed

I see something else I gotta fix while in there. I used 300v wire for the choke install and it should be 600v. I'll have to see if we have some here at work. I currently have 2 leads coming off the main board then soldered to the leads on the choke as they weren't long enough to reach when the choke was originally installed. Wonder if a molex connection would work here. Could be handy if I have the board out again in the future.


----------



## jcmjmp

tweed said:


> I see something else I gotta fix while in there. I used 300v wire for the choke install and it should be 600v. I'll have to see if we have some here at work. I currently have 2 leads coming off the main board then soldered to the leads on the choke as they weren't long enough to reach when the choke was originally installed. Wonder if a molex connection would work here. Could be handy if I have the board out again in the future.



Doesn't the choke you bought already come with wire? Seems odd.


----------



## tweed

jcmjmp said:


> Doesn't the choke you bought already come with wire? Seems odd.



yes, but where I located it on the chassis it wouldn't reach easily. So I just ran two leads from the board and then soldered them to the two leads from the choke.


----------



## Buggs.Crosby

jcmjmp said:


> Doesn't the choke you bought already come with wire? Seems odd.



the wire on the choke as it comes is to short to install it where he did
i dont have the reverb pan so i put mine in a direct line with R71....MM should really make the leads longer than needed


----------



## Buggs.Crosby

JCM....think you might have some time to proof read this interactive PDF in about a month?


----------



## tweed

well I found some 600v wire here at work temp rated at 125C, it has a pretty thick sleeve on it but should work just fine. Now if I could only put my hands on the solder sucker we had here I'd be all set, otherwise I may have to use desolder braid.


----------



## Buggs.Crosby

tweed said:


> well I found some 600v wire here at work temp rated at 125C, it has a pretty thick sleeve on it but should work just fine. Now if I could only put my hands on the solder sucker we had here I'd be all set, otherwise I may have to use desolder braid.



braids suck for these boards....i would not use one.....go to rat shack and get a sucker there


----------



## tweed

Well getting an early start on this today as it's 7am here. One stupid question as the coffee hasn't taken affect yet, when putting electrolytic caps in, (changing out c12 on main board) is the striped side negative or positive? Looking at the other caps on the board it looks like the stripe side would be negative.

*must have coffee*.....


----------



## tweed

Oh and Buggs you were right. The braid is not the way to go for this project. I'll be hitting Radio shack shortly to get a bulb sucker, etc...


----------



## jcmjmp

Buggs.Crosby said:


> i may need another pic or two but based off of what you have i will make a connections chart for you.....wanna know where Conn 3 goes?....just scroll over it and it will tell you



You have to be very careful when you do that because that connector might go somewhere else depending on the board rev and issue number.


----------



## Buggs.Crosby

jcmjmp said:


> You have to be very careful when you do that because that connector might go somewhere else depending on the board rev and issue number.



thats why i'm trying to get every known scheme on these....if something cannot be confirmed it will be omitted....and it will tell you this


----------



## tweed

So does anyone have a step by step hookup of the tranny on the right of the board for a 50w? I think I still have them in the correct order but would be nice to know for sure. Mainly the two purple and 3 blue connections, to bad they didn't make them all different colors.


----------



## TwinACStacks

You mean like this?

Marshall DSL Transformers

 TWIN


----------



## tweed

Kinda like that.

Here's my tranny






Here's the leads coming off the tranny






And here's where they connect to the main board. 






Just have to figure out where the three blue leads and the two purple leads hook to and in what order if that makes sense. After that gets done and I hook all the "cons" together, it's bias and test time.


----------



## jcmjmp

tweed said:


> Kinda like that.
> 
> Just have to figure out where the three blue leads and the two purple leads hook to and in what order if that makes sense. After that gets done and I hook all the "cons" together, it's bias and test time.



The blue leads are the 22-0-22 taps (W11/W12/W13), the red/orange are the HT (See Schematics) and the purple are the heaters (W9/W10).

If you're not sure on how to hook 'em up, bring the amp in to a tech.


----------



## tweed

jcmjmp said:


> The blue leads are the 22-0-22 taps (W11/W12/W13), the red/orange are the HT (See Schematics) and the purple are the heaters (W9/W10).
> 
> If you're not sure on how to hook 'em up, bring the amp in to a tech.



I know that the heaters go to w9 and w10 and the 22-0-22 blue wires go to w10 w11 and w12. Just not sure if the purple connections, even though they are both heaters need to connect in a certain order, like the first purple off the tranny goes to w9 then the second goes to w10 or if that even matters, maybe since they are both heaters they are interchangeable. That make sense?

Same for the 22-0-22.


----------



## jcmjmp

tweed said:


> I know that the heaters go to w9 and w10 and the 22-0-22 blue wires go to w10 w11 and w12. Just not sure if the purple connections, even though they are both heaters need to connect in a certain order, like the first purple off the tranny goes to w9 then the second goes to w10 or if that even matters, maybe since they are both heaters they are interchangeable. That make sense?
> 
> Same for the 22-0-22.



The heaters are interchangeable but not the center tap for the 22-0-22 taps.


----------



## tweed

jcmjmp said:


> The heaters are interchangeable but not the center tap for the 22-0-22 taps.




Is there an easy way to determine the order of the 22-0-22? Or am I making it to hard? Are outside blue leads on the tranny the 22's and the middle lead is the 0. Connect a 22 to w11, 0 to w12 and 22 to w13...


----------



## jcmjmp

tweed said:


> Is there an easy way to determine the order of the 22-0-22? Or am I making it to hard? Are outside blue leads on the tranny the 22's and the middle lead is the 0. Connect a 22 to w11, 0 to w12 and 22 to w13...



one word of advice - Always double check what you read on the 'net and make your own readings with your own multimeter. Its easy enough to check. If you can't do that, bring it to a tech. With schematics and a DMM, this is a very simple job.


... and this should be in a separate thread - it has nothing to do with modding the DSL.


----------



## tweed

jcmjmp said:


> one word of advice - Always double check what you read on the 'net and make your own readings with your own multimeter. Its easy enough to check. If you can't do that, bring it to a tech. With schematics and a DMM, this is a very simple job.
> 
> 
> ... and this should be in a separate thread - it has nothing to do with modding the DSL.



Ahh sorry about that.. Thanks for the help though


----------



## jcmjmp

tweed said:


> Ahh sorry about that.. Thanks for the help though


no prob! Good luck with your amp!


----------



## javier pintos

well i tried r12 last night and do notice the change, i did not necesarily got a pissed off irish man (dont know any drunk irish man) but rather a drunken mexican tequila dude, however i just tried it like 5 min with some gator clips, i´m planning on getting Graham´s mode shitching for the green channel so i will try it more then with an external switch to bridge r12 on the fly, is there any risk on doing it while operting the amp?

can i assume the same can be done for the clean mode on the corresponding resistor?, more or less what i´m looking for is to do the higher/modern gain and delay/chorus stuff on the clean with my ME50, classic rock (ACCD, Sabbath and the likes) on the crunch and heavier classic on the lead 1-2 when i can find a way to make them chunkier, i would like to have them as chunky as the crunch mode, so i´ll read the 11 pages to find out what to do, unless someone saves me the long read

How does R30 mod opposes to R12mod? doing both wouldn it be like making the lead 1 and 2 sound fantastic with the deep grit as Twin mentions but at the same time keep the crunch more or less same to stock and making it overall more plexierish?

Cheers


----------



## el zilcho

Hey, before I go on a jumper-clippering expedition...

Does anyone know how to get some real midrange in the clean channel?


----------



## el zilcho

So it looks like C4 (100pF) is the bright cap for the clean mode. C6 (1000pF) gets added in parallel to C4 when the crunch mode is engaged. Is this right?

I was thinking about swapping C4 and C6 so that the clean mode gets some more upper mids but the crunch mode will still sound the same. Not sure if that will get me the midrange I want or if the clean will be too bright after that. There might be a way to put a cap across the volume pot and tie one leg in with the mode switch...


----------



## el zilcho

Tried it, didn't like it. 1000pF doesn't bring the corner freq low enough. Just made the clean mode quacky.

What I really need is to bring up the ~500hz range.


----------



## Joey Voltage

el zilcho said:


> Tried it, didn't like it. 1000pF doesn't bring the corner freq low enough. Just made the clean mode quacky.
> 
> What I really need is to bring up the ~500hz range.



I'll help you with the clean thing, but It wont be until later, I'm not on my computer right now.


----------



## TwinACStacks

If Anybody can Help You El Zilcho, it's Joey. After all the Mod is Named after him.

 TWIN


----------



## Joey Voltage

Okay Zilcho put everything to stock, on the pot board increase R2 to 56K, and C2 to .01uf that will give you more mids for your clean. If you need more, and like the frequency, increase R2 to 100K, and C2 to .0047uF. You will also notice a slight gain boost/volume increase.


----------



## el zilcho

Okay I put C4 and C6 back to their original values. I didn't have a 56k lying around so went ahead and tried the 100k and .0047uF for R2 and C2. 

This seemed to just add a lot of low end and gain. The stock values were .047uF for C2 and 10k for R2, is that right?


----------



## Rogue

Hey fellas! I'm a new happy DSL50 owner. I've read through most of this thread. I knew I'd be doing some modding to it to tailor to my wants and needs, and that's cool. It's a great base! 

It needed new tubes so I ordered up all of them. After I give that a go for a while and determine what I want to do with it, I'll be asking you guys lots of stupid questions! Just a heads up. 

Rocking amp!


----------



## rockback

LOL Maybe I'll feed my ipod into it and walk away for a day


----------



## Rogue

Ok guys, I have a question. I've spent some quality time with my amp. I have have noticed on the red channel a top end sound that drives me nuts. I've experienced this sound on other amps. I call it a "wirey" sound because that's the word that describes it best to me. It might be considered sizzle by others as it kind of sounds like that, but I don't know if we are talking about the same thing. I would also call it "thin", but may not be an accurate description. It doesn't matter whether I turn the treble and presence down, it still has that sound just with less treble. 

It's just an unnatural, sharp, "wirey" kind of sound. Hard to describe really. It goes away somewhat as the volume increases. I had the same issue with my 1959x. That same wirey sound. I clipped the bright caps on the board and it sounded much better. I think I ultimately just changed the value. 

I stumbled across this thread....

JCM 2000 DSL (Page 3) - Joe's Guitars, Amps and Gear - Joe Bonamassa Official Message Board

I believe this guy experienced what I am experiencing now. mantegna said he did the "C12 mod" (apparently clipped a cap out of the circuit) and he as very happy with it. 

It is also (assuming everyone is talking about the same cap) in the list of mods in this thread. "C12 Lower to 150pf or REMOVE (I removed it)" 

So, does this do something similar to clipping the bright caps on 1959x (seems like they were C17 and C18 or something like that)? On the 1959x, the mod made the amp less aggressive, but made it more natural sounding and more musical, IMO. I'd like to do the same with the DSL. I'll likely find a value that works best for my normal playing conditions to keep it somewhat aggressive, but still more natural. 

I'll get my new tubes tomorrow. They might take care of, but I have doubts they will.

Is this the right tree to be barking up? Are there any other mods that might help address this top end wirey sound?


----------



## el zilcho

There are a bunch of different things you can do. It really depends on if you're just trying to get rid of "fizz" (the really high frequencies that are mostly noise up above 6khz), or if you're wanting to change the upper midrange voicing of the amp. 

Two things I would consider before you mod it:

1. The bright cap (C12) has less and less of an effect the higher the gain is set.
2. When you change the upper voicing of your amp, listen to it off-axis as well as on. What may sound perfect standing straight in front of the amp may end up sounding like it's under water if you take a step to the side (how the majority of people in an un-mic'd venue will hear it) or play it in the context of a drummer with loud cymbals.

-Clipping C12 on the pot board will get rid of most of the fizz and also take away the upper midrange bite that the cap adds.

-Lowering C12's value from the stock 470pF will reduce the upper mids more or less depending on how much you decrease the value. It will also reduce the fizz slightly.

-Increasing the value of C9 on the tube board will roll off the top end and get rid of the fizz. Using 1000pF rolls off highs at 3.2khz. This effects both the clean and dirty channels. I found that this was a little too dark on the clean channel so I went with 560pF for a roll off at 5.7khz.

-For a high end roll off on just channel B, you can attach a capacitor across the wiper and ground of the channel's volume pot like this:http://local.anchorstates.net/images/tsl/vr2-47pf.jpg. 68pF will roll off around 5.1khz, or you can use 100pF for a 3.5khz roll off.


----------



## Rogue

Thanks el zilcho. Yes, I understand I will aslo that I'll loose other frequencies to get rid of the fizzies. If there is a way of getting rid of the fizzies without loosing some of the upper mids, that'd be great. As I understand it, a capacitor doesn't just cutoff at a certain frequency but is linear...which means it's going to get into other areas we might not want. 

I suppose that is the price of fizzy removal.

I doubt I'll be using a great deal of gain ever on the red channel. Probably 1 o'clock is as high as I'll go. No amount of off axis gets rid of these fizzies. 

That is some great info. I haven't really noticed any 'fizz' on the green channel, but it wouldn't hurt my feelings to help fatten it up a little and give it a little more naturalness. 

I think I'll start with C9 on tube board and see where that leads. If I get somewhere cool on the green channel, but the red still needs some top end taken off, I can still tweak C12, right? 

On the green channel, do you use it in crunch mode or clean? Crunch mode has a lot of bottom end and I'm curious if changing C9 pronounces that even further.


----------



## Rogue

And I also found this...

http://www.marshallforum.com/workbench/3626-dsl-100-c17-treble-bleed-cap-mm-ot-questions.html



> For a noticeable tonal change (warmer tones) you must replace C16 on THE MAIN BOARD (if your amp was built in 2005 or after - pcb JCM2 60 02 -, C12 if before).


Mine is a 2006, is this information correct?

I don't know what my board numbers are. I'll find that out tonight.


----------



## el zilcho

I'm not sure about the board change. The bright cap will be next to R19.

Honestly, I would just try a 68pF cap on the channel B volume pot first. That will get rid of most of the fizz and not make the channel overly dark. The upper mids won't change and channel A won't change.


----------



## Joey Voltage

el zilcho said:


> Okay I put C4 and C6 back to their original values. I didn't have a 56k lying around so went ahead and tried the 100k and .0047uF for R2 and C2.
> 
> This seemed to just add a lot of low end and gain. The stock values were .047uF for C2 and 10k for R2, is that right?



try decreasing the value of the cap, if you notice, you are only really dealing with a fixed tone network in that area, which is gain dependent.


----------



## Rogue

el zilcho said:


> I'm not sure about the board change. The bright cap will be next to R19.
> 
> Honestly, I would just try a 68pF cap on the channel B volume pot first. That will get rid of most of the fizz and not make the channel overly dark. The upper mids won't change and channel A won't change.


Thanks. I'll give that a try first. I'd like to affect the mids as little as possible.


----------



## el zilcho

I left the 100k in R2 and tried decreasing C2. The more I decreased C2, the more bass and gain I got. Going back to .047uF brought the bass back to where it was. I tried a 4.7uF to see what that would do, but it didn't sound much different than .047uF.

Now that the bass is under control, I can hear how that 100k is adding a decent amount of mids. It sounded kind of muffled though, so I paralleled a 560uF with C4 and it opened it up nicely. 

I'll mess around with it more when I get some time.


----------



## Joey Voltage

el zilcho said:


> I tried a 4.7uF to see what that would do, but it didn't sound much different than .047uF..



It won't, because you are passing most of the audible limit at that point. The 100K IS what is doing the work of increasing the mids, not the cap. I mentioned the cap in order to tailor the upper limit of the bass in order to include frequencies above 500hz, but yes, added gain and muddiness might (and seems to be) a side effect, if we cant limit the lower bass spectrum somewhat, treble can be easily increased as well. I will take another look at the scheme.


----------



## el zilcho

I've been playing it for awhile with 100k in R2, .047uF (stock) in C2, and 560pF in C4. I was going to reduce C6 to compensate the crunch mode, but I found I didn't mind the way it sounded and left it at .001uF.

It sounds pretty good like this. The clean mode has a tone that is close to the crunch mode now but with less gain. The only downside is that there is slightly more gain on the clean than before, so I don't get as much of a gain increase when footswitching to the crunch mode.


----------



## Joey Voltage

el zilcho said:


> I've been playing it for awhile with 100k in R2, .047uF (stock) in C2, and 560pF in C4. I was going to reduce C6 to compensate the crunch mode, but I found I didn't mind the way it sounded and left it at .001uF.
> 
> It sounds pretty good like this. The clean mode has a tone that is close to the crunch mode now but with less gain. The only downside is that there is slightly more gain on the clean than before, so I don't get as much of a gain increase when footswitching to the crunch mode.



play around with the resistance value, try 68K or 82K to see if it would be just enough to bring it down a notch to make it a bit more useable.


----------



## el zilcho

I'll give that a try. Thanks for all the help!


----------



## Rogue

Well, I had to order several of the parts listed on page 1, so it'll be a few days at least before I can start doing them. I also ordered a choke as well. Looking forward to it. Spent a lot of time familiarizing myself with the boards and labeled where all all the connectors go. A little prep while waiting. 

I did clip C12 just to see what happened. I thoroughly enjoyed the end result. I thought it was a more musical, pleasing tone. 

So, I haven't really seen anyone describe what all these mods do as an overview before and after.

What should one expect from the amp when these mods are done? Are they designed around making the amp more natural and musical? That's what I'm after really. I'm not into making it more breewwwtal or anything. Not my thing.


----------



## TwinACStacks

Rogue, I actually was after Less fizzy less Tubby low end with slightly DECREASED Gain. If You follow the mods and Use a Plexi Speced Power Trans from jcmjmp (Lydian), and find a C1998 Dagnall clone from Marstran along with a 3H choke, It will sound Like a Plexi on Roids. Let me check my exact mods I have them logged because I deviated a Little from the Joey Mods on the first Page slightly. I will give you the different values shortly.

 TWIN


----------



## TwinACStacks

Okay, My deviations are R30 on Tubeboard I decreased to a final 190K, C8 on Frontboard I changed it out to a final .001uf And R12 on the frontboard I lowered from 470 to 220K. I didn't do the Deep Switch thing either. All the rest of the Joey mods were done as per the thread.

 TWIN


----------



## Rogue

Thanks Twin, that sounds exactly like where I'd like to see this go. There are some other things that sound worthy of trying out as well, but I mainly want to do these mods and see where it's at then. 

One thing I may ask about later, depending if I still experience the same thing after the mods, is something for the green channel (crunch mode). As it sits now with the gain around 5-6, it has a pretty cool JTM45 thing going on. It has that big bottom end and will get a nice chimey clean or dirty grit depending on your guitar volume or pick attack. But I also like cranking the gain as well and getting a little more into superlead land. However, cranking the gain pushes the bottom end too much and I have to adjust the bass (even then it's too loose--hopefully the choke helps that). 

So what I'd ultimately like is to have the ability to bring the gain down to 5-6 on the crunch for some JTM45ish big bottom end but when cranking the gain the bottom rolls off and is a bit tighter to be more superlead like. 

I'm sure it's possible, but I wouldn't know how to do it....at least not yet anyways. Has anyone tried something like this? 

With a little care and investment, I think this can be a wicked amp that has a lot of cool tones.


----------



## TwinACStacks

The choke will tighten it, The Grid Blockers really do it, and That R12 on the frontboard is Green Channel SPECIFIC. It tightens, gives more brightness, (the green channel is kind of dark, that's why you get the Flub), and decreases the gain just a Tad. Best MOD is the OT Xformer.

 TWIN


----------



## Rogue

Thanks. I've got a 5H MM choke on the way. It already has the 5.6k grid blockers. I'm pretty stoked about getting all the mods in place and tweaking it to my liking. I'll eventually do the OT. Not sure which one I want to go with though. I know a guy that really likes the Marstran he put in his. Plenty of time to decide on that one.


----------



## el zilcho

Joey Voltage said:


> play around with the resistance value, try 68K or 82K to see if it would be just enough to bring it down a notch to make it a bit more useable.



I used 82k (R2) and also did the tone shift/mid boost mod (33k in R36 and parallel with R35) that jcmjmp posted back at the beginning of this thread. With that in it keeps the mids about the same but I get a little more gain gap between clean and crunch. I also reduced C8 to .001uF.

I like the mid boost thing on the lead channel too.


----------



## Rogue

I have stumbled on an issue (maybe). I am looking at c12 on the tube board. What is on there is a 4n7 100v electrolytic cap. It is a JCM2-60-00 issue 6 board. 


The diagrams available 02 issue 5 for 100w and 02 issue 7 for 50 watt. Both those diagrams have this cap listed 4n7 63v. 

The 00 issue issue 1 diagram has completely different listing for this cap. It is calling it c7, but is still a 4n7 63v cap. 



The part I order was the one listed on page1...MKS2-1/63/5T WIMA Polyester Film Capacitors

First question is will this cap work for that? Does the 00 issue 6 boards need the 100v electrolytic there? 

Second, on the board is listed a + for c12. Both diagrams also show a + and use a different symbol than normal caps. The cap I ordered has no discernible positive or negative indication. Sooo, is this a problem? 

Thanks


----------



## TwinACStacks

Nope. Sounds like at the factory they ran out of 4n7 63V Polyesters and used an electrolytic of the same value with a slightly higher voltage rating. Other than the schematics there really isn't any circuit changes to the DSLs that I'm aware of. *Maybe jcmjmp can enlighten us a little???* Most of the caps in the mods have a 5mm lead spacing. Wimas are GREAT caps.

 TWIN


----------



## Rogue

Thanks Twin. 

What is the purpose of it needing to be polarized (according the schematic and the board)? Is using a non polarized cap in its place safe? 

C12 on my board is all the way on the edge (or the preamp tube side), just above W14 and below con2. It seems to be the same one as in the diagram for the 50w. 

Thanks


----------



## TwinACStacks

It doesn't need to be. The 4n7 you are replacing ISN'T Polarized. This is why it's important to know WHICH board you have and be able to trace it on a schematic. The original 00 issue 1 board is identical, but as you have noticed, is numbered differently. These boards are also used in the TSL where there MAY need to be a polarized cap? AFAIK. One of the Techs can correct me if I'm wrong. I'm assuming Marshall designed them to use either type of cap, that's why there are polarity markings because an electrolytic WON'T work backwards.

 TWIN


----------



## Rogue

Well, that's why I asking because I want to make sure I'm not doing something that will mess things up. The cap that is on there is a polarized cap, whether it needs to be or not, I don't know. It even specifies it in the diagrams. 

Thus far, the JCM2-60-02-iss7 50w schematic appears to be the same as my board. Everything I've traced has went to where it says it should on that schematic...with the exception of the 100v cap instead of a 63v cap.  Better to be safe than sorry.  I agree though, they probably had to use these for whatever reasons.


----------



## el zilcho

_Clean channel tangent continued..._

I used the amp in rehearsal and found that the clean mode was still a little muddy trying to cut through drums at higher volumes. I backed R2 down to 50k and then played a show that night, sounded much better than previous outings but still a little dark. The next day I upped C4 to .001uF and put the 560pF in C6. I also went back to 100pF in C9 on the tube board (I have a cap across channel B's volume pot for fizz control which I may end up increasing slightly).

I like this VERY much now. Along with the tone shift button mod and reducing C8 to .001uF, the clean channel is right where I wanted to get it. Plenty bright, and no more ridiculous amounts of bass or crazy scooped eq.


----------



## Rogue

el zilcho said:


> _Clean channel tangent continued..._
> 
> I used the amp in rehearsal and found that the clean mode was still a little muddy trying to cut through drums at higher volumes. I backed R2 down to 50k and then played a show that night, sounded much better than previous outings but still a little dark. The next day I upped C4 to .001uF and put the 560pF in C6. I also went back to 100pF in C9 on the tube board (I have a cap across channel B's volume pot for fizz control which I may end up increasing slightly).
> 
> I like this VERY much now. Along with the tone shift button mod and reducing C8 to .001uF, the clean channel is right where I wanted to get it. Plenty bright, and no more ridiculous amounts of bass or crazy scooped eq.


How does it sound in crunch mode?


----------



## el zilcho

Pretty much the same as stock, just with a little more mids and less of the really deep bass.


----------



## Rogue

Well, I have done some mods and it sounds pretty kicking. Much more musical, IMO. There are some issues I'd like to try and address further. 

The mids/upper mids tend to not be as present as I want. They are there, but seem buried if that makes any sense. 

Also, it tends to sound a little harsh..kind of that can of bees sound but not bad....I'd like to try and smooth that out further. 

And I'd like to try and get a little more of that Marshall "quack" thing happening. 

This applies to both channels. 

I did deviate on a few things while looking at other suggestions and that might have had a detrimental effect. Here's what I did:

Front Board:

1M on wiper to ground on VR3
C12 removed
C10 replace with .0022uf
C8 replace with .0022uf 
R20 jumper

Main Board:

C9 replace with .001uf
C12 replace with .68uf
R14 replace with 2.7k
C46 replace with higher voltage

Also a tone shift option mod:

Front Board:

R36 replace with 15k
C22 jumpered

Installed a 5H MM choke. 


I think the amp sounds better all the way around. I still can't help but feel the upper mids are kind of buried, or drowned out or something and I think it can still be smoother sounding. Anything I did above that might be inadvisable? Any suggestions to try to address further my needs above. 

Thanks


----------



## TwinACStacks

Rogue said:


> Well, I have done some mods and it sounds pretty kicking. Much more musical, IMO. There are some issues I'd like to try and address further.
> 
> The mids/upper mids tend to not be as present as I want. They are there, but seem buried if that makes any sense.
> 
> Also, it tends to sound a little harsh..kind of that can of bees sound but not bad....I'd like to try and smooth that out further.
> 
> And I'd like to try and get a little more of that Marshall "quack" thing happening.
> 
> This applies to both channels.
> 
> I did deviate on a few things while looking at other suggestions and that might have had a detrimental effect. Here's what I did:
> 
> Front Board:
> 
> 1M on wiper to ground on VR3
> C12 removed
> C10 replace with .0022uf
> C8 replace with .0022uf
> 
> Main Board:
> 
> C9 replace with .001uf
> C12 replace with .68uf
> R12 replace with 2.7k
> C46 replace with higher voltage
> 
> Also a tone shift option mod:
> 
> Front Board:
> 
> R36 replace with 15k
> C22 jumpered
> 
> Installed a 5H MM choke.
> 
> 
> I think the amp sounds better all the way around. I still can't help but feel the upper mids are kind of buried, or drowned out or something and I think it can still be smoother sounding. Anything I did above that might be inadvisable? Any suggestions to try to address further my needs above.
> 
> Thanks





JUMPER R20 This has a Huge impact.
Change C8 on frontboard to .001 (I think You will like it better)

Then Play around with R30 on the Mainboard Using a pair of test leads try lowering it from 470K I personally liked around 190K this will brighten the Darker green channel boominess (it DOES affect all channels) and decrease some gain and FIZZINESS, (don't worry this amp still has WAY too much Gain), Don't go too far or you will lose most of your bottom end.

Try changing that input resistor R12 on the mainboard back to .68 and see if your mids don't come back. By almost quadrupling the value of R12 you have attenuated a shitload of signal going to V1.

You will get a smoother sound when You replace that under-speced stock Output Xformer!!!!! I STRONGLY suggest a Marstran C1998 Clone (100W) or a 784-139 (50W) You can also use the 784-128, some feel --*opinions*-- that this one has a little more oompfh to the low end. It has the buried 100v tap in it. $125.00

http://marstran.com/

jcmjmp also has Plexi-speced laydowns on his Lydian website, if you prefer a more stock look. I can't tell you how his outputs sound, as I have no experience with them other than some clips, but his Power Trans FUCKING KILLS!!!!! Take THAT to the Bank.

http://www.lydian.ca/Marshall_DSL.html

TWIN


----------



## Rogue

Opps, sorry, I did jumper R20 and that R12 is supposed to be R14 (the one parallel to C12). I didn't do anything to R12. I think I will put R14 back to the original value. 

If I reduced C8 to .001uf, wouldn't that decrease the amount of upper frequencies passed, and as result decrease some of the upper mids too? 

I only tried like a 82K piggybacked on R30. That was fairly extreme and I suppose I should try something to more in between. I wasn't liking the decreased gain on the green channel with the 82k...if I find a value I like for the red channel, can I increase the gain on the green channel? 

Thanks again....


----------



## TwinACStacks

Good question, I know R30 is Global. Maybe Joey or JC can help here, with upping just the green after the R30 mod. Try 190K (470+1M+470). I'm a messenger not a REAL tech.

 TWIN


----------



## Rogue

Alright, I changed R14 back to 1.8k and that made huge difference. That woke up the sleeping upper mids. It's brighter too, but still not fizzy. I don't know what difference C12 at 1uf compared to .68uf, but I'm really liking it as it is. 

I'm on the fence about C8. I might try out some different values later on. At .0022uf, it's a little dark and bassy with the deep switch on, but takes pedals like a champ and gets fat. I kind of like it as it offers a nice difference with the red channel. Turning the deep switch off, it's not too bassy at all. 

Not sure I want to do anything else to it at the moment. Sounds great. My next move may be the output tranny. I've heard a few say the Marstran sounds warmer and fuller than the MM. 

Has anyone tried multiple tannies and compared them?


----------



## Rogue

Oh, and had some leads setup to mess with R30 and never touched them when I started playing. Sounded great.


----------



## diesect20022000

Landshark said:


> Now here's a good one... It says tone shift on the front plate... Is there a value to produce a "mid boost" rather then a cut?



THAT makes some sense! I can't bare to scoop my mids in general but, on a Marhsall that's sacrillege! The mids are what MAKE the Marshall! Besides of course Jim and the factory workers


----------



## TwinACStacks

Rogue said:


> Alright, I changed R14 back to 1.8k and that made huge difference. That woke up the sleeping upper mids. It's brighter too, but still not fizzy. I don't know what difference C12 at 1uf compared to .68uf, but I'm really liking it as it is.
> 
> I'm on the fence about C8. I might try out some different values later on. At .0022uf, it's a little dark and bassy with the deep switch on, but takes pedals like a champ and gets fat. I kind of like it as it offers a nice difference with the red channel. Turning the deep switch off, it's not too bassy at all.
> 
> Not sure I want to do anything else to it at the moment. Sounds great. My next move may be the output tranny. I've heard a few say the Marstran sounds warmer and fuller than the MM.
> 
> Has anyone tried multiple tannies and compared them?



Yep. (I've messed with 5 DSLs since they came out)--That's why I suggested Marstran, (that is unless you were as lucky as I was to get an UN-Used ORIGINAL NOS C1998 off Fleabay for $75.00 + shipping). If YOU are happy with the sound STOP RIGHT WHERE YOU ARE. That's the whole point of modding it.

Now get those Trannies in there, some good NOS TUBES in the PRES and You are there!!!!

 TWIN


----------



## el zilcho

Rogue said:


> I think the amp sounds better all the way around. I still can't help but feel the upper mids are kind of buried, or drowned out or something and I think it can still be smoother sounding. Anything I did above that might be inadvisable? Any suggestions to try to address further my needs above.
> 
> Thanks



If you still feel like channel B is lacking in upper mids, you're definitely gonna want something back in C12 on the pot board.


----------



## Rogue

Ok, I'm pretty happy with where it's at EQ wise. I'd like to warm her up a little though. It sounds sort of cold. I'm not talking about darkening it, just warming up the tone to be a little more organic, or natural. 

Any suggestions?


----------



## Rogue

As an FYI, I replaced C16 on the mainboard with .01uf. That really warmed it up considerably. It darkened the amp a bit, but was easily compensated by tone controls. 

I might try a .022uf and see what happens. That may be too much. Got some other things to try, if any success, I'll let you guys know.


----------



## splatter

forgive me if this has been addressed but I just don't have time to read all 15 pages of this thread . Can someone give me a run down of what the mods on the first page do for you tone wise ?


----------



## Buggs.Crosby

splatter said:


> forgive me if this has been addressed but I just don't have time to read all 15 pages of this thread . Can someone give me a run down of what the mods on the first page do for you tone wise ?



here are the first set of mods...as in Twins first post



TwinACStacks said:


> For those who need/want to KNOW what these mods DO, (courtesy of Joey):
> 
> on the pot board:
> 
> put a 1M resistor from the wiper to ground of Vr3: This has a dual function. It limits the amount of drive signal possible for low frequencies below 169hz (not taking in account for any other low frequency roll off's below this point of course). full up, frequencies below this point will be down -6db, and flat. it also slightly alters the peak response of the shelving filter created by R19,C11, and Vr3.
> 
> keep C12 or remove: Keeping C12 alters the R19,C11,Vr3 shelving filter further by moving the beginning of the upward shelf high at lower gain settings (because the top half of Vr3, anc C12 are now in series with R19/C11 ignoring other circuit impedences of course) giving an edgier sound. when about 3/4 of the way up the shelving effect becomes negligable, and eventually the cap is shorted out by Vr3. Removing it obviously will darken the tone of OD1, and OD2 by removing this effect, but also does so because this now puts larger resistance in series with the grid of the next valve, whose input capacitances will creat a lowpass filter with this resistance, and bleed highs further.
> 
> replace C10 with a .0022uf: Reduces the amount of low frequencies passed on to the next stage in conjunction with R19, Vr3, and the source impedence of the driving stage. this has the bennifit of tightening the sound by somewhat tailoring the bass content within the guitars useable range, and can encourage a higher mix of second order harmonic content (but thats for another discussion). this will also help with potential blocking.
> 
> jumper R20: adjusts the strenght of the afformentiond shelving filter.
> 
> on the tube board:
> 
> C9 1000pf (.001uf)creats a single pole high pass roll off of around 3.2Khz which is around the fundamental of highest note of the guitar. there are also very few useful harmonics for guitar above this, or that can really be reporduced by most guitar speakers. it also can reduce hiss, as well as rolls off the glassy harmonics of the 220K plate load.
> 
> C12 1Uf provides a more useable mid shelving for overdriven guitar while retaining some current induced feedback for low frequencies. also sounds good for the clean mode as well
> 
> Joey Voltage
> 
> BE CAREFUL!!!!!! The voltages inside these amps can KILL YOU....DEAD. If You are unsure about what You are doing ASK!!! Or take/send your Unit to a qualified Tech, any of the Techs behind this thread are outstanding!!!
> 
> 
> 
> 
> TWIN


----------



## ToddOwnz

I need some advice guys! (this is the best place for it  ) So, my 8/4 ohm speaker outputs don't work. The 16 ohm mono still does...My guess is a grounding issue but really I'm just guessing...I haven't had time to tear into it yet so I wanted to see what you guys think. The 16 ohm output is grounded straight to the chassis right? And the other two are not?? What do you guys think the best course of action is?



TwinACStacks said:


> One last preventive measure, On the rear of the chassis the speaker output jacks should have separate grounds installed. the 4&8 ohm jacks are grounded through the 16 ohm jack, (which Bypasses via an open/close contact), the 4&8 Ohm jacks when the 16 Ohm is used. Sometimes this contact doesn't close because of Dirt etc. so when You are plugged into the 4, 8, or Both, the Amp is actually seeing No load at all and: Bye-Bye OT and Maybe more. If You use only the 16 Ohm jack this is not a concern. This can be accomplished by soldering a short piece of wire to the shoulder of W6 Ground connection and to one of the metal bands on either the 4 or 8 ohm jack that is closest to the inside rear surface of the Chassis. When this is done however there will be no auto disconnect. ALL 3 jacks will be active ALL the time. Please DO NOT try and run 3 Cabs at the same time!!!


----------



## TwinACStacks

Todd, You asked the Question and posted the answer all in one shot.

I feel so "Un-needed" *sigh*.....

 TWIN


----------



## ToddOwnz

LOL @ Twin...do you think this would cause the 2 speaker outputs to stop workiing suddenly?

I always used one of the 8 ohm outputs up until 2 weeks ago when I got myself the 1960a cab. I did notice it was tough at first to jack into the 16 ohm output the first time I used it...maybe the contacts not closing  I'm hoping to tear into it later


----------



## TwinACStacks

ToddOwnz said:


> LOL @ Twin...do you think this would cause the 2 speaker outputs to stop workiing suddenly?
> 
> I always used one of the 8 ohm outputs up until 2 weeks ago when I got myself the 1960a cab. I did notice it was tough at first to jack into the 16 ohm output the first time I used it...maybe the contacts not closing  I'm hoping to tear into it later



THAT my friend, IS the symptom/problem of a bad grounding contact in the 16 Ohm Jack.

 TWIN


----------



## sfb

Hi everyone. How much voltage should choke be rated max? 300V? 400V? And another question: I´m going to get JJ KT77´s to my DSL50 but what pretubes should I get? Would JJ ECC83S be to dark? I´ve done VR3/1M, C10 and R20 mods to my amp.


----------



## rockgod212

hi all dsl users, im new to this forum so i want to introduce myself. i have built a metro 2203 to AFD specs so far and i just finished modding my DSL, so i want to tell you all what i did to the DSL 100 and see if anybody can suggest future mods for it.

1. i replaced all the resistors with 1/2 watt koa speers CF
2. i replaced all bias resistors with 1 watt CF
3. all new sozo signal caps with .1uf in phase inverter
4. 250pf over R23
5. C1998 marstran OP transformer
6. 5.6k swampers
7. replaced the 3 pin/ dual bias pot with a single 10k bias pot
8. snipped out C46
9. winged C el34's biased to 37mA per tube/ bias holds up really well with the bias mods.......ecc83 pre's 
10. mercury magnetics mar100 choke
11. raised the mother board 1" and used normal chassis mounted power tube sockets with short fly leads for connections back to the board

every thing else is stock value for issue 5 board.

now i like the clean/ crunch channel as it is or has more of the classic marshall crisp tone. 

but i dont think i like the red/ lead 1-2 channel that much. it sounds a little too harsh-trebely with ice picky gain. i would like to smooth it out a bit with more compression with more low end, so what can be done to make that happen on the red channel. 

is it the swampers that affect this or the new op tranny? 

i still need to read through these threads, but i wanted to post this info.

all in all the amp does sound better, but any help on these issues would be great....


----------



## rockgod212

i have the jcm2-60-00 issue 5 board on my dsl 100, but when i modded the amp and put new resistors in i used the schematic for jcm2-60-02 issue 5. is there a difference in the 2 schematics or boards?

what do i do now?


----------



## diesect20022000

sfb said:


> Hi everyone. How much voltage should choke be rated max? 300V? 400V? And another question: I´m going to get JJ KT77´s to my DSL50 but what pretubes should I get? Would JJ ECC83S be to dark? I´ve done VR3/1M, C10 and R20 mods to my amp.



That's a subjective question but, if you don't like dry or 
"metal" the JJ pre's aren't likely to be your bag. I put a NOS 7025 in V3 a GT inV1 and a JJecc83s inV2. That sounds decent. I have the E34L's in my DSL and they aren't bad. stable and do have more low mid thump with MOST of the EL34 mid harmonic chewyness.


----------



## sfb

diesect20022000 said:


> That's a subjective question but, if you don't like dry or
> "metal" the JJ pre's aren't likely to be your bag. I put a NOS 7025 in V3 a GT inV1 and a JJecc83s inV2. That sounds decent. I have the E34L's in my DSL and they aren't bad. stable and do have more low mid thump with MOST of the EL34 mid harmonic chewyness.



I already got those tubes. KT77 work great with modded DSL. One ECC83S just went dead after 3 days. I´ve heard there is some issues with quality.


----------



## rockgod212

im new to this forum, so i wanted to introduce myself and what ive done to my dsl so far, and i could use some help with it. i think im good with the board version i have, so scratch my last post.

but i do have a question about the swampers, i changed them to the 5.6k's and im not used to the sound of them.....the amp is loud, but thin sounding and lacks the deep bass it once had. my metro 2203 has 5.6k's and it is deep and full. is that the swampers or could i have gotten a bad set of tubes?

i also put a choke and c1998 op transformer in it and replaced all resistors with 1/2 watt koa speers and 1 watt bias resistors and modded the bias pot to the single 10k. also put sozo caps in it as well.

it doesnt sound the way i thought it would sound after all of this, so what else can i do to restore some lowend or solve some of these minor issues?


----------



## Wilder Amplification

rockgod212 said:


> im new to this forum, so i wanted to introduce myself and what ive done to my dsl so far, and i could use some help with it. i think im good with the board version i have, so scratch my last post.
> 
> but i do have a question about the swampers, i changed them to the 5.6k's and im not used to the sound of them.....the amp is loud, but thin sounding and lacks the deep bass it once had. my metro 2203 has 5.6k's and it is deep and full. is that the swampers or could i have gotten a bad set of tubes?
> 
> i also put a choke and c1998 op transformer in it and replaced all resistors with 1/2 watt koa speers and 1 watt bias resistors and modded the bias pot to the single 10k. also put sozo caps in it as well.
> 
> it doesnt sound the way i thought it would sound after all of this, so what else can i do to restore some lowend or solve some of these minor issues?



Before you can understand what is really going on, gaining an understanding of grid swamper resistors and what they do is in order.

The swamper resistors are there to snub out HF (high frequency) oscillation. They do this by forming a low pass filter with the Miller capacitance of the control grid that exists within the power valves.

With a 5K6 resistor, the LPF corner frequency is well and above the pass band at which the speaker can even reproduce. This means that there will be no noticeable rolloff in the highs in the "audible" pass band.

However, use a high value like a 220K and that will shift your corner frequency well into the audio pass band. This will end up attenuating the high frequencies.

So...why does your amp now sound thin? Well...with the 220K resistors you were masking the brightness of the preamp. Once you changed them to 5K6 you shifted that HF corner frequency up out of the audio pass band, which is a good thing. However, due to Marshall's inferior preamp design now you've uncovered an issue that lies within the preamp itself.

Now with the added brightness you have overshadowed the beefy lows and mids. But this should be corrected for in the preamp so some tweaking of the preamp will be in order. DO NOT change the swampers back to the 220K. This adds resistance to the grid leak circuit which can lead to instability issues bias-wise so leave them as a 5K6 (and before you ask why Marshall did that, they did in fact have bias stability issues on earlier issue PCBAs). The place to correct for this issue is in the preamp. Read up on some of the earlier threads to learn what tweaks you can do.


----------



## rockgod212

jon, 
thanx for explaining that to me, i get it now. ill just start with some of these mods from early in the thread and do them one at a time and play test the amp from there.

but any other advice that is not already on this thread that you might have would be a great help.

one question though, some drop that 220k plate resistor back down to 100k, should i do that?


----------



## Wilder Amplification

rockgod212 said:


> jon,
> thanx for explaining that to me, i get it now. ill just start with some of these mods from early in the thread and do them one at a time and play test the amp from there.
> 
> but any other advice that is not already on this thread that you might have would be a great help.
> 
> one question though, some drop that 220k plate resistor back down to 100k, should i do that?



I would definitely do that and if C12 on the valve board is a 4.7uF cap, I would change it to something like a 0.68uF. That will drop the gain of the first stage some...which it has too much anyway, and changing the cap will shelve the lows out of the early gain stages which reduces low end distortion and helps to tighten up the lows somewhat.


----------



## rockgod212

hey jon,
thanx for that advice on what to do, it was exactly what this amp needed. i put the .68uf sozo in c12 and jumped another 220k over the 220k plate of v1 and jumped r12 on pot board, just these 3 things alone brought my amp back to life after being dead for so long. i still have to crank it up, but sounds good so far. i got all of my tone controlls back and the massive low end i like with this amp. ill try some of the other mods a little later, right now i want to play this thing loud.


----------



## rockgod212

scratch my last post, as i just cranked it up and it sounds the same with those few changes. 

the amp still feels real stiff and midrangey with no harmonicly rich overtones.
i still need to do the pot board mods...... 

but are there any other changes to the main board i can do to loosen this amp up? if i cant get this thing to sound right, i might have to put a higher value swamper in. more help is needed.


----------



## rockgod212

where is the tone stack is in this amp? 

where are the signal caps for it, specificly the cap that affects the bass response?

and where is the presence cap?


----------



## Wilder Amplification

I don't think it's that it's "stiff". I think it's that the lows are still farting out on you.

Now before I give you some more tricks, how do you have your EQ set (Bass/Mid/Treble/PResence)? Also, are you engaging the Deep switch?


----------



## rockgod212

i usually set the eq's......bass-6/7, mids-5, trebel-5, presence-5/7
i always use the deep switch and always use lead mode 2.


----------



## Wilder Amplification

rockgod212 said:


> i usually set the eq's......bass-6/7, mids-5, trebel-5, presence-5/7
> i always use the deep switch and always use lead mode 2.



Have you done the pot board C12 mod yet?


----------



## Buggs.Crosby

rockgod212 said:


> i usually set the eq's......bass-6/7, mids-5, trebel-5, presence-5/7
> i always use the deep switch and always use lead mode 2.



if i used those settings i would pierce the ear drums of unborn children within a 100 mile radius.....listen to what Jon tells you and learn to use your EQ settings in a different manner.....do you use this at home or in a band mix situation?
it took me a bit of time to dial my mods in (variations of Jon and Joeys) but man was it worth it....i can almost nail Zakk with my passive duncans.....Marty gave me the final piece i needed by telling me to line my cab with Daycril....another huge plus.....keep in mind you have a Marshall not a Boogie....too much of the wrong low end is a bad thing.....Jon will get you there but some of what you want may come from learning new EQ settings


----------



## Buggs.Crosby

i hope i did not hurt with providing that info Jon!


----------



## rockgod212

yeah i did some these mods...

i snipped out r12 for the green channel- i like this mod, its like an 800 on steroids. i also snipped out c12 for the red- it darkened up a bit, i like it so far. 

changed c12 to .68 sozo, changed r13 to 100k, and put 220pf over r23 those helped some.

how much of what im hearing is due to changing the OP tranny to the c1998 marstran, using all sozo caps, and adding a choke? or is it in deed the change of the swampers that changed the sound so much?

i think i was just used to the compressed sound it had before these mods.
im going to play it with the band tonite and see what needs to be done. not to mention ive been playing my 2203, so im not used to the high gain structure of this amp anymore. although i like the gain of the amp, i just need more lowend freqs to come through. 

it sounds as if i had a wah on all the time, nasaly mid heavy or when tubes go bad, loose all the lows. i think jon is right the lows are just farting out, so i just ordered some parts, so ill play it for awhile as is, then mod the hell out of it.

thanx for all the tips guys......ill get it sounding right soon....


----------



## 00jett

> i snipped out r12 for the green channel- i like this mod, its like an 800 on steroids



Perhaps one of the techs could explain this to me but I don't see the point in pulling r12 out. If im not mistaken it puts c7 in series with c8 and the output coupling cap from v1 which drops the overall cap value to like 420pf??? Would this not create a huge drop in the low end, by the time you get to 82hz it would really be rolled off.? I know the low end can be flubby but take too much out and it would just be thin.. Maybe I have this wrong but I like r12 left in the amp like it is in the jcm 800 2203/2204 amps and increase gain elsewhere in the amp if that is the desired result.

Edit: Went back & read though this thread where this mod was talked about, and many seem to really like it so I see that I have something wrong in my thinking.


----------



## rockgod212

does anyone have a blank or spare mother board for this amp? i would like a blank slate to mod on.


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## Wilder Amplification

rockgod212 said:


> does anyone have a blank or spare mother board for this amp? i would like a blank slate to mod on.



Phat chance on finding one of those.



00jett said:


> I know the low end can be flubby but take too much out and it would just be thin..
> 
> Edit: Went back & read though this thread where this mod was talked about, and many seem to really like it so I see that I have something wrong in my thinking.



00jet...it's not so much about how much low end the amp has. It's where they're adding it that makes it fart out.

On a good amp with tight/punchy overdrive, the lows are shelved out in the early stages, then recovered later on after the overdrive has happened. This adds clean bass to the distortion.

However, on the DSL/TSL, Marshall never shelved the lows out of the very early gain stages which leads to adding distortion to the bass, which makes the amp fart out. Throw in the fact that the very first stage has way to much gain to start with...which is the reason for changing out the plate resistor on the first stage from 220K to 100K.

It's not about just simply "adding bass". It's WHERE you add that bass that makes all the difference.

Now since I don't have a DSL here to experiment with, anyone who wants to test this mod and report their results is more than welcome to. It involves changing the C28 cap on the pot board, which is part of the "Deep" circuit. I know changing its value will shift the low end boost up into a more useful bass range for guitar, but in terms of whether to use a higher or a lower value I can't really tell so if someone would like to experiment, try dropping C28 on the pot board to some lower values and report the results. This may help to recover some of the low end that was lost due to shelving the lows in the early stages. You may also wanna try raising C29 on the same board.

If the result doesn't yield fruitful results try going the opposite direction in value with either or. You can always go back to the stock 10uF's here if neither yields a fruitful result.


----------



## Joey Voltage

Wilder Amplification said:


> Now since I don't have a DSL here to experiment with, anyone who wants to test this mod and report their results is more than welcome to. It involves changing the C28 cap on the pot board, which is part of the "Deep" circuit. I know changing its value will shift the low end boost up into a more useful bass range for guitar, but in terms of whether to use a higher or a lower value I can't really tell so if someone would like to experiment, try dropping C28 on the pot board to some lower values and report the results. This may help to recover some of the low end that was lost due to shelving the lows in the early stages. You may also wanna try raising C29 on the same board.
> 
> If the result doesn't yield fruitful results try going the opposite direction in value with either or. You can always go back to the stock 10uF's here if neither yields a fruitful result.



This is a standard mod that I do for Every DSL that comes to me, and I think even I posted this mod a couple of pages back on this thread when JCMJMP asked, so it's on here somewhere. the standard marshall frequency is indeed too low for guitar use at around 50-55hz:

however You do not have to change C28, and C29, you just have to pick one of the two to shift the frequency. C28 is an arbitrary value, that helps sets the value of simiulated inductance, which is about 900mh in this application, and you can work around what ever it is. so all you have to change out is C29 to shift the frequency (or just C28 which ever one is easiest for you). instead of 10uf, I always put in .68uf - 2.2uf dpending on taste

HOWEVER, this is an application where cap type/dielectric and resistor values really will matter, and you may want to use a crappier cap like an electrolytic, or a tantalum for this application especially in a guitar amp, or else the Q will be too narrow, and peaky. 

if you only have a poly cap, you can work around it in other ways. 

Happy tweaking!

regards,

JV


----------



## 00jett

> 00jet...it's not so much about how much low end the amp has. It's where they're adding it that makes it fart out.
> 
> On a good amp with tight/punchy overdrive, the lows are shelved out in the early stages, then recovered later on after the overdrive has happened. This adds clean bass to the distortion.
> 
> However, on the DSL/TSL, Marshall never shelved the lows out of the very early gain stages which leads to adding distortion to the bass, which makes the amp fart out. Throw in the fact that the very first stage has way to much gain to start with...which is the reason for changing out the plate resistor on the first stage from 220K to 100K.
> 
> It's not about just simply "adding bass". It's WHERE you add that bass that makes all the difference.
> 
> Now since I don't have a DSL here to experiment with, anyone who wants to test this mod and report their results is more than welcome to. It involves changing the C28 cap on the pot board, which is part of the "Deep" circuit. I know changing its value will shift the low end boost up into a more useful bass range for guitar, but in terms of whether to use a higher or a lower value I can't really tell so if someone would like to experiment, try dropping C28 on the pot board to some lower values and report the results. This may help to recover some of the low end that was lost due to shelving the lows in the early stages. You may also wanna try raising C29 on the same board.
> 
> If the result doesn't yield fruitful results try going the opposite direction in value with either or. You can always go back to the stock 10uF's here if neither yields a fruitful result.



Ahh ok this is starting to make sense a bit. So let me see if I have this right. I was looking at one specifice part of the amp and scratching my head, but as a whole there is bottom end added further down.

I have not messed with C28 on the pot board, but I have fiddled with C29 as both you and Joey have suggested, I put it at 2.2uf and found it made a world of difference, but I have since taken another approach with my DSL, and never touch the bass boost. It stays off. 

For my personal tastes I find an amp can be too tight, which is odd because I have said the opposite on this forum before. I changed the cathode bypass caps on V1 to .68uf and 1uf respectively (now that I remember 1uf for the second gain stage was stock) which tightened up the amp, but I added low end in other parts to actually make the amp more classic sounding. Yes it can get a bit loose and flubby if not dialed right, but its different the the farty lows the amp had stock. Its just this huge wall of marshall goodness now that I couldn't get with the bass boost. Maybe Im crazy

Anyway thanks for taking the time to explain that to me.

BTW: changing out that 220k plate resistor to 100k was one of the best things for the amp I found


----------



## JCM900GUY

can anyone help me out on this? i have a Jcm 900 4100. the amp sounds amazing but in order to get my desired tone and volume i have to push the master volume on the gain channel past "12 o'clock"...i had a dsl100 that was much louder at 3 or 4.....is there something i can do to boost the volume? other than a volume boost pedal of course...would changing the volume pot help? and if so what kind?


----------



## Buggs.Crosby

try a short cable in the loop.......thank Jessta for that tip


----------



## Wilder Amplification

00jett said:


> Ahh ok this is starting to make sense a bit. So let me see if I have this right. I was looking at one specifice part of the amp and scratching my head, but as a whole there is bottom end added further down.



Exactly. Imagine trying to place a Boss EQ with a low end boost in front of an amp that's already way overdriven. It would sound like pure raw and fresh dogshit.

But put the pedal in the loop AFTER the overdrive and it's just nice clean and tight bass provided the power amp is not overdriven.

The Deep circuit on the JCM2000 series adds low end at the very output of the amp. It doesn't actually ADD it...it's already there...but it reduces the amount of low frequencies that get cancelled via the negative feed back loop while leaving the mids and highs unaffected. The result is nice, clean and tight bass.


----------



## Paramedic006

Jon-When I get the Choke from you is there anything I should do while I have the amp apart? Reflow solder, resistor changes, caps that sort of thing. I to would like to get my crappy bass response remedied.


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## Buggs.Crosby

If you have not done it already make sure you do the 16, 8, 4ohm mod.....could save your O.T


----------



## Paramedic006

hey Buggs-I haven't done it yet but I did read the posts for that and I plan on doing that. I've been reading other posts and I guess I'm looking for a not so flimsy bass response on the clean, settings: Bass 6-7, treble 6-8, mids 4-5. Number 2:Not necessarily more gain, cuz thats ok, I guess a more useable gain especially on red and red boost. Number3reventative measures that should be done. In the process of changing out the PT, OT, choke with MM through Wilder. My DSL50 sounds good now but its like a rev limiter on a car. Sounds good but I know it can sound a little.


----------



## thrashcomics

are any of you guys located near northern california? id like to get some mods done to my dsl 50 but would rather not ship it anywhere.


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## joemarshalljmp

If someone put out a dsl cap and resistor mod kit with a bunch of stuff to experiment with, I would pay.


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## Buggs.Crosby

joemarshalljmp said:


> If someone put out a dsl cap and resistor mod kit with a bunch of stuff to experiment with, I would pay.



Contact JCMJMP he had them


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## joemarshalljmp

I saw someone had briefly mentioned changing r13 with 100k or jumpering it does any body have anything about this or what board its on?


----------



## 00jett

Definately do not jumper the R13 that was talked about because that was on the tube board and is the plate load resistor. Changing it to 100k tames the gain a bit and also C12 on the same board should be changed to 1uf or .68uf at the same time. This tightens up the amp and lowers the gain early on.

This is what was discussed earlier in this thread.


----------



## joemarshalljmp

00jett-so you are talking about the valve board


----------



## 00jett

Yup, those were some tweaks on the valve board talked about in earlier pages.


----------



## joemarshalljmp

Im sorry, its hard to keep track what board their talking about.


----------



## thetragichero

just put in an order with mouser for the parts needed for the first post in this thread!
once i get the amp back from the cap job, it's time to open `er up!


----------



## thetragichero

question on the stock 1/4" jacks:
are they durable? any reason to replace with switchcraft?
thinking about at least putting a stereo jack for the footswitch


----------



## ellyka112

Joey Voltage said:


> yep



I'll post a "mid boost" mod when I get a chance to look and analyze that part of the circuit.


----------



## rockgod212

if im looking at this schematic right for the power tubes pins 1 and 8 are tied to ground via r6 and r9 which are 1ohm resistors. 

is it possible to just run a bias test pin off of pin 8 of each power tube for an easier way to bias this amp, as i modded my bias circuit to the 1-10k pot and i removed the 3 pin circuit as i dont like it.


----------



## Wilder Amplification

rockgod212 said:


> if im looking at this schematic right for the power tubes pins 1 and 8 are tied to ground via r6 and r9 which are 1ohm resistors.
> 
> is it possible to just run a bias test pin off of pin 8 of each power tube for an easier way to bias this amp, as i modded my bias circuit to the 1-10k pot and i removed the 3 pin circuit as i dont like it.



What's not to like about it? The pins are tied right to that resistor anyway so installing test points to the resistors would be doing the same thing that those pins did.


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## rockgod212

i removed the 3pin/bias circuit and im now using a single bias pot. i dont like the way the 3 pin circuit was set up, i dont think its very accurate having to read bias on two tubes at once, i would rather be able to read bias from each tube just like my 2203. the reason i was going to use test pins is because my bias pot is chassis mounted and adjusted outside of the amp right by the tubes and its impossible to read from pin 8 on the socket from the board side.


----------



## Wilder Amplification

rockgod212 said:


> i dont like the way the 3 pin circuit was set up, i dont think its very accurate having to read bias on two tubes at once,



Can you tell us exactly why this is not a good thing?


----------



## TwinACStacks

Wilder Amplification said:


> Can you tell us exactly why this is not a good thing?



 It's because I can't count that high.... 3.

 TWIN


----------



## jcmjmp

Wilder Amplification said:


> What's not to like about it? The pins are tied right to that resistor anyway so installing test points to the resistors would be doing the same thing that those pins did.


*
If you're referring to the bias pins on the DSL chassis, one improvement I could see would be to replace the CON cable with soldered wires directly on to the PCB. Aside from that, the dual bias circuit is really nice. 

I agree with Wilder on this one though - removing the little bias board seems like it wouldn't really improve anything on the amp.*


----------



## jcmjmp

ellyka112 said:


> I'll post a "mid boost" mod when I get a chance to look and analyze that part of the circuit.



The mid boost was already discussed in this thread. I had posted ways to add more mids a while back.


----------



## rockgod212

biasing from the 3pins for 2 tubes per side at once assumes that all the tubes are matched and i have found that not to be true, so what if the tubes are overly under matched as i have seen or used. i think it is more practicle to measure and set bias from each tube. plus its easier. set it and forget it.

but, i never used the 3pins, i always used a bias probe, but i think the dual bias balancing act is a pain in the ass to get right, and at least in my amp one side always seemed to drift and run hotter than the other side no matter how accuately it was set. so after i found this article on eurotubes i modded the bias circuit to a single 10k pot, and it works great. i just want to be able to measure the bias from each tube with the pin8/pin1/1ohm to ground like my metro 2203, so i dont have to use the probes.


----------



## Wilder Amplification

rockgod212 said:


> biasing from the 3pins for 2 tubes per side at once assumes that all the tubes are matched and i have found that not to be true, so what if the tubes are overly under matched as i have seen or used. i think it is more practicle to measure and set bias from each tube. plus its easier. set it and forget it.
> 
> but, i never used the 3pins, i always used a bias probe, but i think the dual bias balancing act is a pain in the ass to get right, and at least in my amp one side always seemed to drift and run hotter than the other side no matter how accuately it was set. so after i found this article on eurotubes i modded the bias circuit to a single 10k pot, and it works great. i just want to be able to measure the bias from each tube with the pin8/pin1/1ohm to ground like my metro 2203, so i dont have to use the probes.



If you know how to read a multimeter and how to properly interpret what the voltage measurements are telling you this is absolutely not an issue. I have absolutely no idea how one could think otherwise. Just as jcmjmp stated, hard wiring the board as opposed to using connectors between the bias board and the main board is a much needed improvement (because connectors can and do fail).


----------



## thetragichero

i did the joey mods today
once the contact cleaner cleaner i sprayed into the tube sockets has way too much time to dry (overnight), i'll fire it up and see what smokes (hopefully nothing!)
thank satan for camera phones... this thing has more cables than my damn computer!


----------



## thetragichero

shit, V5 red plates regardless of which tube i move there


----------



## Wilder Amplification

thetragichero said:


> shit, V5 red plates regardless of which tube i move there



More than likely you have a bad grid swamper resistor on that socket. Check the voltage on pin 5 of the socket...it should be a negative voltage. If that voltage is not there then that resistor is definitely toast.


----------



## rockgod212

i just got done finishing all of these mods on my dsl-100 that i learned on here and all i can say now is wow what a different beast this amp is now. but i also added a few touches of my own.....a .047 in the tone stack leading to the bass pot as i needed more lows, and i prefer a .68 on the presence as it beefs up the low mids some, added a 47pf silver mica on vr2 (i saw this somewhere and it works to take some fizz out or its a shelving thing i guess) did everything except for the R30 mod and some other small cap changes. i still would like to smooth out the highs a bit more, so is there anything i can do for that to happen. 

oh and the one 10k bias pot ( you have to lower R77 to 4.7k to get it in range) mod works great, although i might have to upgrade the bias filter caps later on. i put my old mullards in and biased to 36-38mA and it will rip your freaking head off. i just love the green channel now, i did keep a 220k in there, it just sounded and felt good that way.


----------



## rockgod212

is it possible to use the tone shift switch for a 2 in 1 tone stack type thing, so switch out would be stock 33k/470pf and switch in would be 56k/250pf...?

also is it possible to add a resonance control?


----------



## rockgod212

i lowered r12 to 220k and i think i like that for the green channel, but has anyone tried a different value or different type cap on C7, as that is the green channels bright cap, and it looks to be a cheap ceramic cap at best?

i also lowered C12 to 150pf and i think i might try a 220pf i have laying around later on, but what does C13 affect, as that looks to be part of that circuit somehow?


----------



## panzerschreck

i dont feel like reading every post but is there a mod out yet to make the fx loop foot switchable


----------



## surface54

i have a 1998 DSL100

front board JCM2-61-00
main board JCM2-60-00

in this picture is this the correct c12 for the lead channels treble bleed mod? 

and is there a way to short it out without having to remove one leg? like a old school gator clips trick or something? i guess id still have to take the board out either way.
thanks guys!


----------



## rockgod212

yep thats it....change the value or remove it....dont jumper it, unless you use it with a switch or something....


----------



## surface54

does a *50v* #pf work fine for the c12?
i know there some rated for 500v and others are less (like the ones at radio shackasis)
are 50v. just dont want that rating to hurt anything in the long run.


----------



## chuckharmonjr

In a serious mode tho, I concentrated on making the green crunch a plexi from hell, I didnt pay much attention to the red channel at all. After a quick look at the schematics, 50 volt should work, get a 100 volt if you can find it. Grab a 500 volt if yo ucan find it. The voltage rating has no effect on tone, its just better to have the ability to handle voltage than not. Capacitance value is the tone adjustment. When it comes to voltage rating...bigger is better.


----------



## surface54

went to the radioshack today and got the 100pf, installed it flawlessly.
though it was nerve racking cause my gun is a desoldering gun that sucks up solder and it didnt seem hot enough i had to leave it on there longer than i liked and i did not at all cost want to lift any tracings. what is a good wattage gun you guys like to use? i know too hot would probably be even worse at least with a 30watt you could control it better. 

c12 100pf:
this is a small affect but very crucial mod for the lead channels imo.
i can now have the gain on 3 on the lead2 channel and crank the volume and get a much bigger mid range almost sounding like the green with more saturation. im super pleased! 
if they shipped it with this value stock i dont think it would of gotten such a bright wrap about it. and for some folks bright is harder to work with than dark. now the amp sounds even and heavier, the power chords have a little more dark texture to it without that extra trebley focus on top, and trust me there is still alot of organic treble to make it just fine. 100pf is the spot. i also listened to it completey off and it was good too. just not as defined.

thanks for everyones help! 
cheers

pale ale on me tonight!


----------



## Stymie13

I posted over in the DSL Conspiracy but thought since it was Joey Mod specific I'd share this here too. I got my first chance to play and listen to a stock DSL 100 side by side with my Joey Mods version. Tubes and speaker/cabs aside (perhaps not a perfect apples to apples) the difference in clarity, definition, punch, and just an overall organic sound was unbelievable. Sorry, no clips but here's the break down:

Green Channel

These were still pretty close actually. Both amps had plenty of punch, warmth, and jangle but the modded amp had a much tighter bottom end. This was particularly noticeable on clean (which I never use) rather than crunch.

Red Channel 

This is where the difference was stunning. Master on 4, the modded amp on Lead 2 was thick, warm, punchy, and natural with excellent note definition. The stock amp seemed to lose all definition on any gain settings past 4 or 5. With the gain maxed it was absolute mud. The modded amp gain on 10 is still clear, articulate, tight and decays into warm musical feedback.

Man, I remember loving my DSL even before I modded it. But it's been so long since I played a stock one I kinda forgot how much difference these mods can make. Well worth the time and effort.


----------



## Stymie13

I think I posted this before, but just for reference here's where I ended up with the mods:

Front board:

C12 removed
C10 changed to .0022uf
R20 removed and jumped
VR3 1M resistor on wiper to ground

Tube board:

C9 changed to .001uf 500v
C12 changed to 1uf 63v
R30 changed to 220K ohm
R7  changed to 5K6 ohm
R10 changed to 5K6 ohm
R66 changed to 5K6 ohm
R70 changed to 5K6 ohm
R67 changed to 1w 220K ohm 
R68 changed to 1w 33K ohm 
R69 changed to 1w 220K ohm
R77 changed to 1w 10K ohm

Rear board:

Ground linked speaker outputs

Installed Lydian OT and 3H choke

So, here's a big thanks to everyone that helped create this monster! Especially Joey V, JcmJmp, Twin AC Stacks, and Marty for the killer preamp tubes


----------



## TwinACStacks

Stymie13 said:


> I think I posted this before, but just for reference here's where I ended up with the mods:
> 
> Front board:
> 
> C12 removed
> C10 changed to .0022uf
> R20 removed and jumped
> VR3 1M resistor on wiper to ground
> 
> Tube board:
> 
> C9 changed to .001uf 500v
> C12 changed to 1uf 63v
> R30 changed to 220K ohm
> R7 changed to 5K6 ohm
> R10 changed to 5K6 ohm
> R66 changed to 5K6 ohm
> R70 changed to 5K6 ohm
> R67 changed to 1w 220K ohm
> R68 changed to 1w 33K ohm
> R69 changed to 1w 220K ohm
> R77 changed to 1w 10K ohm
> 
> Rear board:
> 
> Ground linked speaker outputs
> 
> Installed Lydian OT and 3H choke
> 
> So, here's a big thanks to everyone that helped create this monster! Especially Joey V, JcmJmp, Twin AC Stacks, and Marty for the killer preamp tubes



Great job Stymie. Now pop in that Lydian PT and Your jaw will drop, no SHIT. Now as it stands, your PT is the only weak link in the Chain. I never thought the PT would make a big difference... I was WAY wrong, JCM's P.Tranny is superb.

 TWIN


----------



## JCarno

Stymie, If you don't mind, could you tell how much all this cost and approximately how long it took? Did you do it all at once or a little at a time?
Thanks!


----------



## Stymie13

JCarno:
Although it could certainly all be done at once, I would recommend doing it in stages if you you're patient enough so you can really perceive the effect of each change. For instance, do all the resistor and cap mods and check the amp out. Then do the PT and/or OT, and play. Same with the choke. This is also helpful in the case that you make a mistake (I made plenty) since you can isolate and trouble shoot the work just performed. Depending on your skill and experience, you could do it all in a couple hours. I suppose there is a case to be made for doing all mods at once since it is kind of a pain to completely gut the amp multiple times, although not all the mods require total dis-assembly. I definitely became intimately familiar with the internals and subsequently much quicker each time I took it apart. A work bench or large table in a room where things can be left exposed in various stages is very helpful. Especially a space where you can plug the amp into a cabinet and crank it without having to reinstall the chassis into the head shell. All the caps and resistors were under $20 total. The OT and choke together were in the neighborhood of $200. I forgot to post the capacitor kit I also bought from JCMJMP which I can't recall the cost of anyway. I'm guessing all in all I've got about $300 in the project and way more time than I'm willing to admit. I also did some cosmetics (silver tipped knobs, black faceplate, green power switch, wire mesh front and rear panels) and ditched the reverb tank.

Twin:
I remember you telling me about the PT. I fully intend to do it, it just got bumped on the priority list. I picked up a 5150 for my current band project cause I thought I wanted something with a more aggressive voicing. Not sure it'll win out over the DSL in the end, but I'm going to give it a fair shot. You ought to see the trannies in that thing. They are monsterous! Nearly TWICE the size of the DSL.


----------



## Stymie13

A word of advice to those considering modding their DSL:

If you never turn the amp up past 3 on the master volume, don't bother spending the time and money. I will say that my amp does not sound overwhelmingly inspiring at bedroom volumes. Like many will tell you, the thing really blooms at 4 or 5 on the master. It really takes on an entirely different character and morphs into the earth moving force that it was designed to be.


----------



## JCarno

Hey Stymie, Thanks for the input. I just bought a house so I'll have plenty of time to play above 4 and have a dedicated room to do the work.
I own 2 dsl50s so I can mod one and leave the other stock for reference purposes. 
Sheesh, then I could do a true a/b to hear what all the fuss is about.
The only mod I've done so far on one of the amps is to clip C12. And like you say, not being able to crank the amp, I can hardly hear a difference.
Maybe once I get started you'll let me pick your brain for some help 
Thanks again for you time.


----------



## eddiegj

93DMTX said:


> Alrighty, C9/12 main Bd done. Just removed C46. This is an iss10 bd.
> 
> Worst part was thinking about all those cables...doing it wsn't bad!
> 
> I like it! Tanks for the help! Actually work first time back together.



Ok, I have the same board and I thought it was an issue 6. I copied this quote from Marshall DSL

"Each board also has an Issue number. The issue number applies to a Board ID and is used to track soft changes to the schematics that don’t need a change of board layout. The issue number is printed on the boards and the first visible number after the word «issue» is the issue number." 

In your last picture it is easy to see issue 6. Am I right about this?


----------



## Rahlstin

U may want to get rid of or replace with higher voltage rating that C46 cap over on the rh side of the pic while u have the board out. There are details on this cap and its issues earlier on in this thread.


----------



## eddiegj

I guess I should have removed all the text from my reply except the "This is an issue 10 board"


----------



## eddiegj

Rogue said:


> I have stumbled on an issue (maybe). I am looking at c12 on the tube board. What is on there is a 4n7 100v electrolytic cap. It is a JCM2-60-00 issue 6 board.
> 
> 
> The diagrams available 02 issue 5 for 100w and 02 issue 7 for 50 watt. Both those diagrams have this cap listed 4n7 63v.
> 
> The 00 issue issue 1 diagram has completely different listing for this cap. It is calling it c7, but is still a 4n7 63v cap.
> 
> 
> 
> The part I order was the one listed on page1...MKS2-1/63/5T WIMA Polyester Film Capacitors
> 
> First question is will this cap work for that? Does the 00 issue 6 boards need the 100v electrolytic there?
> 
> Second, on the board is listed a + for c12. Both diagrams also show a + and use a different symbol than normal caps. The cap I ordered has no discernible positive or negative indication. Sooo, is this a problem?
> 
> Thanks



I have the same board as you and have been wondering about that one too. I did all the mods on the first post except that one. lol. Crazy thing is every schmatic that I found shows C12 as polarized. (tube board)


----------



## TwinACStacks

SO, if any of you Guys that have DSLs modded by Joey himself OR you have done the Joey Mods, these can be had Around $15. (maybe less if I get enough quantity for him to make) Self adhesive.






 TWIN


----------



## sfb

Is there some simple mod to add bass on both channels and make the amp darker? My 50 watter is too bright for singlecoils. These are the mods I´ve already done:

Tubeboard:
C9 1nF
C12 1uF

Frontboard:
C10 2n2
R20 jumper
1M resistor wiper to ground on vr3


----------



## jcmjmp

eddiegj said:


> Ok, I have the same board and I thought it was an issue 6. I copied this quote from Marshall DSL
> 
> "Each board also has an Issue number. The issue number applies to a Board ID and is used to track soft changes to the schematics that don’t need a change of board layout. The issue number is printed on the boards and the first visible number after the word «issue» is the issue number."
> 
> In your last picture it is easy to see issue 6. Am I right about this?




This is all explained on my site:
Marshall DSL


----------



## jcmjmp

eddiegj said:


> I have the same board as you and have been wondering about that one too. I did all the mods on the first post except that one. lol. Crazy thing is every schmatic that I found shows C12 as polarized. (tube board)



There are two C12 mods. One on the tube board and one on the front board. Their effects are completely different. 

If you're not sure what you're doing, consult a tech.


----------



## jcmjmp

sfb said:


> Is there some simple mod to add bass on both channels and make the amp darker? My 50 watter is too bright for singlecoils. These are the mods I´ve already done:
> 
> Tubeboard:
> C9 1nF
> C12 1uF
> 
> Frontboard:
> C10 2n2
> R20 jumper
> 1M resistor wiper to ground on vr3



You want more bass? A stock DSL will shake the house with a strat. Tons of bottom. I can't imagine needing more.

A good OT and PT upgrade (hint hint hint) will give you more grunt and presence and a tighter sound but more bass... That may not be want you need. Perhaps the speakers are to blame.


----------



## sfb

jcmjmp said:


> You want more bass? A stock DSL will shake the house with a strat. Tons of bottom. I can't imagine needing more.
> 
> A good OT and PT upgrade (hint hint hint) will give you more grunt and presence and a tighter sound but more bass... That may not be want you need. Perhaps the speakers are to blame.



Speakers are 2x12. Vintage 30 & Eminence Man O War. My DSL is trebly. I don´t know why. If not more bass, at least I need to tame the highs somehow.


----------



## jcmjmp

sfb said:


> Speakers are 2x12. Vintage 30 & Eminence Man O War. My DSL is trebly. I don´t know why. If not more bass, at least I need to tame the highs somehow.



open or closed back cab? The highs can be tamed a little with the C9 cap on the main board.


----------



## sfb

jcmjmp said:


> open or closed back cab? The highs can be tamed a little with the C9 cap on the main board.



Closed Marshall 1936. I´ve already changed C9 to 1nF. Should I change it bigger?


----------



## jcmjmp

Yeah, you could try a larger value. 
Are the speakers broken in? Turning the presence down doesn't help?


----------



## sfb

Speakers are broken in. Just played with the amp and if I could only get clean channel little bit darker. Is there an easy way to do this? Maybe I should also try that C9 swap.


----------



## eddiegj

jcmjmp said:


> There are two C12 mods. One on the tube board and one on the front board. Their effects are completely different.
> 
> If you're not sure what you're doing, consult a tech.



A must read!
http://www.marshallforum.com/workbench/11566-dsl-info-3.html


----------



## jcmjmp

eddiegj said:


> A must read!
> http://www.marshallforum.com/workbench/11566-dsl-info-3.html



Yes, forgot about those. 

There's even a description alluding to the C12 cap on the tube board vs the front board as I mentioned earlier:
http://www.marshallforum.com/workbench/11566-dsl-info-3.html#post101342


----------



## Rahlstin

Well, installed a MercMag OT tonight. Fired her up, already seems to feel more responsive. Didnt crank up yet, will do tomorrow or the next at rehersal. Previously put a choke in. The amp now sounds... Horny... I realize now, that before it was kinda like a cold date, mayby get to 1st base, but now, a little forplay with the guitar and the amp responds like its hot n horny. Kinda went from quiet girl next door to porn star. Its about the only way I can describe it so far. We'll see how it goes in a day or so.


----------



## TwinACStacks

Rahlstin said:


> Well, installed a MercMag OT tonight. Fired her up, already seems to feel more responsive. Didnt crank up yet, will do tomorrow or the next at rehersal. Previously put a choke in. The amp now sounds... Horny... I realize now, that before it was kinda like a cold date, mayby get to 1st base, but now, a little forplay with the guitar and the amp responds like its hot n horny. Kinda went from quiet girl next door to porn star. Its about the only way I can describe it so far. We'll see how it goes in a day or so.



 HHhhmmmm. More RESPONSIVE. I see...

 TWIN


----------



## Rahlstin

Its probably all in my head.


----------



## Rahlstin

It sounded very good in my work room at home, but that was at a very low volume. Took it to practice last night and it has changed the amp's tone alot. Will have to work at it a bit to relearn how to set it up. Id have to say off the top, Im not as impressed at this point about the OT change.


----------



## eddiegj

Ok, just finished the mods on page one. I am impressed! Even the Green Crunch is kick ass. The green crunch channel sounds very close to the red's Lead 1. Lead 1 and Lead 2 sound like a Hot Rodded JCM 800 2203. The only problem I had was the 1mfd cap for C12. Mouser back ordered it and said it would be shipped late April. I settled for a 250v version. Had to get creative to get that sucka in there but it fit. lol. I'll switch it out the order comes in. This was a rewarding and fun experience. Thanks Twin, Joey and the rest of the contributors for posting the info on these pages.


----------



## Alabama Thunderpussy

Rahlstin said:


> It sounded very good in my work room at home, but that was at a very low volume. Took it to practice last night and it has changed the amp's tone alot. Will have to work at it a bit to relearn how to set it up. Id have to say off the top, Im not as impressed at this point about the OT change.



I hate to say it, because you seem like a nice cat and I don't enjoy knowing other people got hosed:

Welcome to Mercury Magnetics' Hype Vs Reality.

"Hay guyz lookit how tall our transformerz are! That makes 'em better. Only $210."

Of course, then there's the "handmade in California" card they, along with companies like Mesa, Tone Tubby and Two-Rock like to pull as if that's going to guarantee it's made better.

In all actuality "Made In California" almost automatically means the product is going to be twice as expensive as everything else for two reasons, mainly:

#1: Just general California entrepreneur arrogance. (Oh, we're so innovative. We're an industry leader, blah blah blah.)

#2: These guys are living in one of the worst economies in the country right now and they are all losing their houses because their adjustable mortgage payments are shooting through the roof. You're damn right they're gonna charge an arm and a leg for what they are making, and they'll go to extraordinary lengths to justify it. If any of these companies have kept their prices the same over the past five years, it's because they cut their cost somewhere. I highly doubt any of them have maintained business throughout the economic downturn.

Companies like Peavey, on the other hand, produce their product in an area of the country where employee wages and cost of living are so low that they still have a profit margin.

Not hard to make a profit when homeboy on the assembly line is putting together $1,400 Butchers for $9 an hour.


----------



## 6StringMoFo

can anyone post before and after tone clips?


----------



## Joey Voltage

Alabama Thunderpussy said:


> I hate to say it, because you seem like a nice cat and I don't enjoy knowing other people got hosed:
> 
> Welcome to Mercury Magnetics' Hype Vs Reality.
> 
> "Hay guyz lookit how tall our transformerz are! That makes 'em better. Only $210."
> 
> Of course, then there's the "handmade in California" card they, along with companies like Mesa, Tone Tubby and Two-Rock like to pull as if that's going to guarantee it's made better.
> 
> In all actuality "Made In California" almost automatically means the product is going to be twice as expensive as everything else for two reasons, mainly:
> 
> #1: Just general California entrepreneur arrogance. (Oh, we're so innovative. We're an industry leader, blah blah blah.)
> 
> #2: These guys are living in one of the worst economies in the country right now and they are all losing their houses because their adjustable mortgage payments are shooting through the roof. You're damn right they're gonna charge an arm and a leg for what they are making, and they'll go to extraordinary lengths to justify it. If any of these companies have kept their prices the same over the past five years, it's because they cut their cost somewhere. I highly doubt any of them have maintained business throughout the economic downturn.
> 
> Companies like Peavey, on the other hand, produce their product in an area of the country where employee wages and cost of living are so low that they still have a profit margin.
> 
> Not hard to make a profit when homeboy on the assembly line is putting together $1,400 Butchers for $9 an hour.



compared to some other companies, they also use the thinnest gauge of wire they can possibly get away with, and do not use any materials that are above in quality compared to any other good company.

You pay the extra premium for their customer service, their reputation, and occasionally some Flashy red or Blue endbells, and thats about it.


----------



## TwinACStacks

Joey I love Your disclaimer at the bottom. Exactly who IS the amp police then?

 TWIN


----------



## Alabama Thunderpussy

I'd like to report for the record that using ultra fast recovery diodes in the rectifier circuit of the DSL 100 makes no perceivable difference to the tone. For those contemplating it, don't waste your time.


----------



## Joey Voltage

Alabama Thunderpussy said:


> I'd like to report for the record that using ultra fast recovery diodes in the rectifier circuit of the DSL 100 makes no perceivable difference to the tone. For those contemplating it, don't waste your time.



There's generally not a tonal difference, like huge Smooth bass, and all that other crap you usually read

The only time a perceivable difference would be audible is if they were stopping junk from getting into the HT supply which can, and does happen with regular ol' 1N's 

A while back on another forum somebody did do a video series scoping out noise reduction methods, and sure enough UF types did quell noise/ringing. It is actually a much better/easier sollution than adding snubbers, which can actually make things worse.

at the same cost of 1N's, you really cant lose.


----------



## Joey Voltage

TwinACStacks said:


> Joey I love Your disclaimer at the bottom. Exactly who IS the amp police then?
> 
> TWIN



Thanks. I really have NO interest in Micro-managing others on here over what they can and can't do with their own stuff, on their own time.

Amp police,Those are the Micro-managers.


----------



## 6StringMoFo

6StringMoFo said:


> can anyone post before and after tone clips?



Anyone?


----------



## Rahlstin

Unable to do so with out reinstalling the original. Im going to play around with a few things and give it some time. Have another show on the 12Mar. Ill see how it is live.


----------



## Rahlstin

Ive got about 8 hours of rehersal time on it now and tonight its sounding way better than the first few hours. Im a bit more ok with it now.


----------



## jcmjmp

eddiegj said:


> Ok, I have the same board and I thought it was an issue 6. I copied this quote from Marshall DSL
> 
> "Each board also has an Issue number. The issue number applies to a Board ID and is used to track soft changes to the schematics that don’t need a change of board layout. The issue number is printed on the boards and the first visible number after the word «issue» is the issue number."
> 
> In your last picture it is easy to see issue 6. Am I right about this?



Yes, That's an issue 6 board.


----------



## jcmjmp

Alabama Thunderpussy said:


> I'd like to report for the record that using ultra fast recovery diodes in the rectifier circuit of the DSL 100 makes no perceivable difference to the tone. For those contemplating it, don't waste your time.



No tonal difference, you're right, but it does help with making the power supply cleaner, with less spikes and transient voltages, which can lead to some damage in the PT and or other parts of the power supply.


----------



## Alabama Thunderpussy

jcmjmp said:


> No tonal difference, you're right, but it does help with making the power supply cleaner, with less spikes and transient voltages, which can lead to some damage in the PT and or other parts of the power supply.



Ya know I have actually noticed that my PT doesn't run as hot as it used to.


----------



## ledvedder

So, what mods would you guys suggest to start with? Which ones make the most difference? 

Also, what exactly will a choke do for the amp?


----------



## 6StringMoFo

I'm getting the urge to put my stock TXs back in


----------



## Buggs.Crosby

6StringMoFo said:


> I'm getting the urge to put my stock TXs back in



try it.....i did......went right back...........though i never did the PT upgrade


----------



## 6StringMoFo

Buggs.Crosby said:


> try it.....i did......went right back...........though i never did the PT upgrade



I guess I just want to hear a difference. LOL You back Buggs? Bout F'n time man


----------



## ledvedder

I went and removed C12. I didn't have any spare caps laying around, so I just completely removed it. Talk about darkening the Lead channels. Wow! I guess I'll wait for band rehearsal tomorrow to see if I like it or not. Playing alone, in my house, it almost seems to dark.


----------



## JayCM800

Guys, i just wanna say that it's very cool to have Joey's contribution on this forum!!! (even if i don't own a DSL) 

We immensely appreciate you, Joey!!!


----------



## Alabama Thunderpussy

Finally got around to installing a choke in mine:

Dropped the wires right below the bobbin. Dressed the drilled hole with a rubber grommet. Looks very nice.






Ran the leads along the perimeter of the chassis, around the PT. I stuck some quick-connect terminals on the ends of the leads, and extended the leads to the solder pads. This way if I need to pull the main board, I simply disconnect the lead extensions from the quick connects and there is no desoldering required. Somebody said "Why not use little plastic clips with double sided adhesive instead of silicone?" Because they have a tendency to lose adhesion in my experience, especially in more humid environments (such as mine).


----------



## Rahlstin

I removed the Mercury Magnetics OT tonight and put my stock OT back in. Amp sounded way better with the stock OT. Im leaving the Mercury Magnetics choke in place because it actually did make a large improvment. The MM OT however has become a big mistake for me. Oh well...... theres alway's ebay.


----------



## TwinACStacks

I wouldn't have used Mercuries in the first place. They were Anti what I was trying to achieve, which was a toned down more vintagey sound on the DSL. For more modern sounds they are tits but pricey. There are better options out there for the $$$$.

 TWIN


----------



## Rahlstin

Well, sometimes you listen to others and the hype and you buy in only to find out that it was the wrong decision. Ive made mistakes and ill make a few more Im sure. Its a risk anyways with this stuff. Just got in from our show tonight. They insisted we go back on and play more so like idiots lol we did. Amp sounds very very good with the stock OT over the MM OT. Ill be keeping it this way for a while. It was a great show, had a stage full of drunk girls, a few mic stands went over..... lots of fun.


----------



## Landshark

jcmjmp said:


> This is all explained on my site:
> Marshall DSL



I think I asked this before, and maybe others have too, but do these correspond to the TSL boards too? I know the TSL has three front boards, but do the main board values correspond to eachother?


----------



## Buggs.Crosby

Landshark said:


> I think I asked this before, and maybe others have too, but do these correspond to the TSL boards too? I know the TSL has three front boards, but do the main board values correspond to eachother?



the main or tube boards are the same


----------



## jcmjmp

Buggs.Crosby said:


> the main or tube boards are the same



The TSL does have 1-2 extra connectors (for the mute and VPR) on them, but they are pretty much the same. You could use a DSL board in a TSL and not use those 2 features.


----------



## jcmjmp

Rahlstin said:


> I removed the Mercury Magnetics OT tonight and put my stock OT back in. Amp sounded way better with the stock OT. Im leaving the Mercury Magnetics choke in place because it actually did make a large improvment. The MM OT however has become a big mistake for me. Oh well...... theres alway's ebay.



The MM stuff is a little sterile/HiFi sounding IMO.


----------



## Buggs.Crosby

jcmjmp said:


> The TSL does have 1-2 extra connectors (for the mute and VPR) on them, but they are pretty much the same. You could use a DSL board in a TSL and not use those 2 features.



i thought the layout and traces were there....just no components?
been a bit since i saw the board


----------



## Landshark

jcmjmp said:


> The TSL does have 1-2 extra connectors (for the mute and VPR) on them, but they are pretty much the same. You could use a DSL board in a TSL and not use those 2 features.



Sweet I'll be checking into the mods soon! I've read through the first 10 or 11 pages and I think I know what I'd like to do with it. Thanks guys!


----------



## Buggs.Crosby

jcmjmp said:


> The TSL does have 1-2 extra connectors (for the mute and VPR) on them, but they are pretty much the same. You could use a DSL board in a TSL and not use those 2 features.





Landshark said:


> Sweet I'll be checking into the mods soon! I've read through the first 10 or 11 pages and I think I know what I'd like to do with it. Thanks guys!




JCM....i have Tim's main board in front of me but not the DSHell......just pics.....everything looks the same


----------



## ledvedder

Does anyone have any before and after soundclips of the mods listed in the original post? I'd love to be able to hear the difference before I start messing with my amp.

Also, can anyone explain what each change accomplishes, sonically? I realize there's electronic explanations for each mod in the original post, but I'd like a bit of explanation of what each one does tonally.


----------



## TwinACStacks

All I can tell You is I did them and they sounded Awesome.

A Guy traded me his *JCM800* for it Straight up. What does that tell You?

I can ALWAYS Build another DSL, ( I have the recipe). They are a dime a Dozen.


If You mod it EXACTLY as I did with a Plexi Dagnall Output and Jcmjmp's Power Transformers it will rip your head off. I don't think anyone has followed my steps EXACTLY Yet, plus I ended up with a couple value changes that aren't in the original post. My goal was to make it a little Calmer and More Plexi-ish, And GET RID OF THAT AWFUL WASP IN A JAR FIZZ.

 TWIN


----------



## ledvedder

So far, I've just changed C12 on the frontboard to 220pF.

For C12 on the mainboard, do I have to use a 1uF WIMA cap, or can I use one of these from Radio Shack?
http://www.radioshack.com/product/i...erName=Type&filterValue=Metal+film+capacitors
http://www.radioshack.com/product/i...Name=Type&filterValue=Electrolytic+capacitors


----------



## TwinACStacks

I wouldn't. The metal film is going to sound sterile and the tantalum isn't high enough voltage plus it will sound like shit.

 TWIN


----------



## Buggs.Crosby

led....where in Jersey are you?


----------



## surface54

I gotta ask about this mod, if there even is one etc..
Presence Mod for a DSL100 
ive already did the c12 mod, works great. 
i assume the presence controls would be in the front board.
only thing i dont like about it is the rather ceramic harsh cut it adds to the tone, its not bad but i just wonder if it could be improved? overall not a make or break mod for me but would be cool to hear what you all think about it.


----------



## Landshark

TwinACStacks said:


> Well Gang, because I'm getting weary of emptying my inbox with questions concerning the DSL INFO thread, LOL, I've decided to post the "meat and potatoes" of the Mods for the DSL series without the additional Banter between contributors. Joey Voltage was kind enough to provide some open-source mods which form the basis for the alterations, Along with input from the rest of the resident BRAIN TRUST: JON, JCMJMP and the MAJOR. My Humblest appreciation and Thanx to all of You. These Guys are GREAT to have on your side folks....
> 
> Me? I'm an electrician but in NO WAY am I an AMP TECH!! I'm just dangerous enough to try it all. I've owned 5 DSLs in a Love-Hate relationship with the Red and Green Channels. (Actually I'm beginning to believe that this is really a SINGLE CHANNEL AMP with 4 Distinct MODES!!!) THIS time around I decided to call upon the experts to help make it True Love, and we all know True love is hard to find...
> 
> 
> FIRST: (AFTER DISCHARGING THE LETHAL VOLTAGES IN YOUR CHASSIS!!!) Determine which version of Boards that Your DSL contains Using this link:
> Marshall DSL
> 
> There are about 5 different Version (issue) boards used. The mods are centered around the Front Board (Pre) and Tubeboard (Main) and are based on THESE TWO VERSIONS, if yours don't match up you have a different version:
> 
> JCM2 60-02 iss5 (Tube) AND JCM2 61-00 iss1 (Front)
> 
> 
> Front Board:
> 
> NOTE: THESE MODS AFFECT THE RED LEAD 2 MODE ONLY (removing C12 will also darken Lead 1)
> 
> 1M Resistor from Wiper to Ground on Vr3 ****
> C12 Lower to 150pf or REMOVE (I removed it)
> C10 replace with .0022 uf
> R20 Remove and *JUMPER*
> 
> **** These can be bridged on the other side of the Board. Find the 4 Pins that are the Actual Pot terminals, (Not the Two Board mounting pins), follow the Traces. The inner one that has R19 on it is the WIPER, the outside one that connects to Con 5 pin 2 is the Ground. ( Using your meter set to continuity works well here) Solder your 1M across these 2 pins leaving the legs long, then bend flat to board using a piece of electrical tape attached to the board to insulate the leads from accidentally shorting out to any other exposed solder connections. Electrical splicing tape works quite well here as it adheres to the board better than vinyl electric tape.
> 
> 
> Mainboard:
> 
> NOTE: THESE MODS AFFECT ALL CHANNELS/MODES
> 
> C9 replace with 1000pf (.001uf) 500V
> C12 replace with 1uf 63V
> 
> Here is a Link for the Caps:
> 
> MKS2-1/63/5T WIMA Polyester Film Capacitors
> 
> 
> Now if You find that the overall texture of the amp is, or has become too dark:
> 
> Mainboard:
> 
> Replace R30 (470k)with 68k to 220k resistor this will Decrease the Fizziness and the OVERALL GAIN as well and also brighten the Amp. I personally Piggybacked, (using a pair of test leads), a range of resistors across the Legs of R30 from 82k to 1M and decided I liked 1M the Best. This brought the Value of R30 to 320k. I then soldered it in place across the legs of R30. This way it is easily changed if I decide on a different value without pulling the PIA Mainboard!!! This particular Mod is pretty much season to taste. One of the Techs or Myself can figure out what value you need for "Piggybacking", or you can try and figure it out yourself:
> 
> R1XR2 Divided By R1+R2= the Total resistance of Both Resistors combined. Use the Value of R30 (470)k for R1 and the resistor You want to try as the value for R2. (Try: 82k, 120k, 220k, 330k, 470k and 1m)
> 
> Also if You find that the Green CRUNCH Mode is too boomy especially with the deep switch engaged:
> 
> Frontboard:
> 
> C8 replace with .001uf to .0022uf (I used .0015uf)
> 
> Here's a link: 168152J100A-F Mallory Polyester Film Capacitors
> 
> 
> THESE ARE THE EXTENT OF THE ORIGINAL MODS.
> 
> 
> Now THIS is the "while You are in there" section of the Mods that SHOULD be performed.
> 
> C46 if You have one. This is an underspeced Cap that apparently is to prevent parasitic oscillations. It can short out and Take out the board it's on, as well as your OT. Either CUT it OUT or replace it with a +1000V version of the same value (22pf). I say "apparently" because I have heard nothing about anyone experiencing oscillations after removing this cap completely.
> 
> Change out the Grid Blockers on the Mainboard. Most versions have 220K in place, replace with a more normal "Marshall" value 5k6 resistor. I'm of the understanding Alan Bradley Carbon Comps are suited quite well for this, I used regular +/- 5% carbon films from Radio Shack that I had on hand.
> 
> The locations for these are: R7, R10, R66, R70
> 
> Also because of frequent run-away biasing problems That appear to be temperature related, Upgrade the Bias resistors. I suggest a more temperature-stable precision metal film 1/4 to 1W, PRP or Vishay Dale.
> Here is a link for the PRPs: Sonic Craft High-End DIY Audio Parts
> 
> The locations and Values of the Bias resistors are: on the Mainboard
> R68 33K
> R77 10K
> R67 220K
> R69 220K
> 
> One last preventive measure, On the rear of the chassis the speaker output jacks should have separate grounds installed. the 4&8 ohm jacks are grounded through the 16 ohm jack, (which Bypasses via an open/close contact), the 4&8 Ohm jacks when the 16 Ohm is used. Sometimes this contact doesn't close because of Dirt etc. so when You are plugged into the 4, 8, or Both, the Amp is actually seeing No load at all and: Bye-Bye OT and Maybe more. If You use only the 16 Ohm jack this is not a concern. This can be accomplished by soldering a short piece of wire to the shoulder of W6 Ground connection and to one of the metal bands on either the 4 or 8 ohm jack that is closest to the inside rear surface of the Chassis. When this is done however there will be no auto disconnect. ALL 3 jacks will be active ALL the time. Please DO NOT try and run 3 Cabs at the same time!!!
> 
> Now for the FUN Stuff:
> 
> Replace the OT and Add a Choke.
> 
> Add a 3H Choke at the R71 Resistor (270R 7Watt) on the Mainboard. Remove R71 and connect the two wires for the choke in its place. You can mount it behind the power Trans at the Rear of the Chassis. You will need to swing the Powerboard out of the way for drilling. TIP: Because this resistor is mounted with a LOT of solder, (and I was a little afraid of overheating and lifting the traces), I simply snipped the body off the Legs and soldered my wires directly to the leg remnants. Very un-professional and very effective.
> 
> A MAJOR sound Modification is the replacement of the puny Stock Dagnall OT. JCMJMP has drop in replacements on: Marshall DSL
> Also they are available from Mercury Magnetics, I believe Jon deals in these. Because I had a deal fall into my lap, I used a replacement for a 100 Watt Plexi: a Dagnall C1998 or the Later version C2668. These you can find on Ebay or VERY good Clones from Marstrans or Metro Amp.
> 
> For those of You electing to go this route, Here are the Wiring Directions For the 100 Watt Dagnall C1998/2668 Plexi Stand-up mount OT.(also the Marstran and Metro Clones)
> 
> NOTE: THIS TRANSFORMER IS FOR THE 100 WATT DSL. FOR 50 WATT use a 784-139 Plexi CLONE.
> 
> Dagnall Plexi Primaries/ Stock DSL Dagnall
> RED.............................................White (goes to V5,V6)
> White.......................................... Blue CT
> Brown.......................................... Purple (goes to V7, V8)
> 
> 
> Dagnall Plexi Secondaries/ Stock DSL Dagnall
> 16 Ohm Green................................Red
> 8 Ohm Yellow.................................Orange
> 4 Ohm Black.................................. Green
> Comm. Brown................................ Black
> 
> For the 50watt 784-139 Clone:
> 
> 784-139 Primaries/ Stock DSL Dagnall
> RED.............................................White (V4)
> Brown..........................................BLUE CT
> White..........................................Purple (V5)
> 
> 784/139 Secondaries/ Stock DSL Dagnall
> 16 Ohm Gray.........................................RED
> 8 Ohm Green.........................................Orange
> 4 Ohm Yellow........................................Green
> COMM. Orange......................................Black
> 
> If desired you can also change out the Power Xformer, although there is much less impact on the sound. They are also available as drop-ins from JCMJMP or Mercuries from Jon. I don't believe there are vintage-type repros available with the low voltage power taps needed for the DSL channel switching at this time.
> 
> You can use some quick connects, I wanted to be neater and installed Molex.
> 
> Lastly, SEEK OUT SOME GOOD NOS TUBES: MartyStrat54 is THE hookup for this.
> 
> For those who need/want to KNOW what these mods DO, (courtesy of Joey):
> 
> on the pot board:
> 
> put a 1M resistor from the wiper to ground of Vr3: This has a dual function. It limits the amount of drive signal possible for low frequencies below 169hz (not taking in account for any other low frequency roll off's below this point of course). full up, frequencies below this point will be down -6db, and flat. it also slightly alters the peak response of the shelving filter created by R19,C11, and Vr3.
> 
> keep C12 or remove: Keeping C12 alters the R19,C11,Vr3 shelving filter further by moving the beginning of the upward shelf high at lower gain settings (because the top half of Vr3, anc C12 are now in series with R19/C11 ignoring other circuit impedences of course) giving an edgier sound. when about 3/4 of the way up the shelving effect becomes negligable, and eventually the cap is shorted out by Vr3. Removing it obviously will darken the tone of OD1, and OD2 by removing this effect, but also does so because this now puts larger resistance in series with the grid of the next valve, whose input capacitances will creat a lowpass filter with this resistance, and bleed highs further.
> 
> replace C10 with a .0022uf: Reduces the amount of low frequencies passed on to the next stage in conjunction with R19, Vr3, and the source impedence of the driving stage. this has the bennifit of tightening the sound by somewhat tailoring the bass content within the guitars useable range, and can encourage a higher mix of second order harmonic content (but thats for another discussion). this will also help with potential blocking.
> 
> jumper R20: adjusts the strenght of the afformentiond shelving filter.
> 
> on the tube board:
> 
> C9 1000pf (.001uf)creats a single pole high pass roll off of around 3.2Khz which is around the fundamental of highest note of the guitar. there are also very few useful harmonics for guitar above this, or that can really be reporduced by most guitar speakers. it also can reduce hiss, as well as rolls off the glassy harmonics of the 220K plate load.
> 
> C12 1Uf provides a more useable mid shelving for overdriven guitar while retaining some current induced feedback for low frequencies. also sounds good for the clean mode as well
> 
> Joey Voltage
> 
> BE CAREFUL!!!!!! The voltages inside these amps can KILL YOU....DEAD. If You are unsure about what You are doing ASK!!! Or take/send your Unit to a qualified Tech, any of the Techs behind this thread are outstanding!!!
> 
> Hope You Guys and Ladies, enjoyed the JOEY MODS THREAD, and good luck with your quests for good tone with the MOST AWESOME MARSHALL HEAD EVER...
> 
> Here are some additional links for Parts:
> 
> MetroAmp - Plexi style amp kits, amp forum discussion, and tech wiki.
> Marshall Transformer Codes
> Mouser Electronics - Electronic Component Distributor
> Antique Electronic Supply
> 
> TWIN



OK, now I just want to be absolutely clear about this. I'm working with a 2006 JCM 2000 Triple Super Lead and all of the components from the DSL Tube board and the TSL tube board are nearly identicle (there are a few that are different but I've already changed them on my TSL main board to match the DSL main board).

Now, If i'm reading this correctly and understanding correctly, the primary things I want to change are in the crunch and lead channel. Info I got from Joey was that Crunch on the TSL is close to the OD1 on the DSL, and then I am assuming that Lead would be like OD2. So the mods will work for these two channels perfectly. The question I have is since there are two boards for the Crunch and Lead, will I have to change out the caps and resistors on both front boards?

Here's what I'm planning on doing, and if my understanding is correct, this should limit the bass frequencies to manage the tightness, cut the noise considerably, darken, warm, and really open up the overall tone:



front board:
C12 removed
R20 jumped
C10 .0022 uf
C8 .001 uf
Vr3 1M

main board:
C12 1uf 63V
R30 220K
C9 1000pf (.001uf)

And install a choke. JCM, I'll be getting in touch with you about getting a choke soon.


----------



## Landshark

surface54 said:


> I gotta ask about this mod, if there even is one etc..
> Presence Mod for a DSL100
> ive already did the c12 mod, works great.
> i assume the presence controls would be in the front board.
> only thing i dont like about it is the rather ceramic harsh cut it adds to the tone, its not bad but i just wonder if it could be improved? overall not a make or break mod for me but would be cool to hear what you all think about it.





TwinACStacks said:


> on the tube board:
> 
> C9 1000pf (.001uf)creats a single pole high pass roll off of around 3.2Khz which is around the fundamental of highest note of the guitar. there are also very few useful harmonics for guitar above this, or that can really be reporduced by most guitar speakers. it also can reduce hiss, as well as rolls off the glassy harmonics of the 220K plate load.



I think this might be what you're looking for... it's not necessarily indicative of a "presence mod" but if I understand correctly this should do the trick.


----------



## ledvedder

Buggs.Crosby said:


> led....where in Jersey are you?



I'm in Bellmawr, exit 4 off the Turnpike. It's about 5 minutes outside of Philadelphia.


----------



## ledvedder

TwinACStacks said:


> I wouldn't. The metal film is going to sound sterile and the tantalum isn't high enough voltage plus it will sound like shit.
> 
> TWIN



Any ideas where I can get the WIMA caps from? Mouser appears to be out of stock and says they won't get an more until June.

Will this one work, Digikey part number 495-1169-ND?


----------



## TwinACStacks

Yep. They will work. BY the Way I finally settled on C8 as .001 and R30 as 190K. That C1998 Stand up Plexi OT is the secret. You can get them from Marstran.

 TWIN


----------



## Buggs.Crosby

ledvedder said:


> I'm in Bellmawr, exit 4 off the Turnpike. It's about 5 minutes outside of Philadelphia.



Ha.....i used to live near Browning rd and the Pike.........now i'm in Williamstown
about a 1/2 mile from Geets diner so if you need anything i'm kinda close


----------



## ledvedder

Buggs.Crosby said:


> Ha.....i used to live near Browning rd and the Pike.........now i'm in Williamstown
> about a 1/2 mile from Geets diner so if you need anything i'm kinda close



Very cool. I'm right off of Browning rd.


----------



## surface54

Landshark said:


> I think this might be what you're looking for... it's not necessarily indicative of a "presence mod" but if I understand correctly this should do the trick.



ok thanks for the feedback.


----------



## RickyLee

OK fellas. Need some help as I am starting on trying to install a few of the mods at the beginning of this thread.

For the Lead 1 channel mod for the 1 meg resistor across the pot VR3 wiper to ground, it says that the terminal on the pot that is connected to R19 is the wiper. Well I have the PCB out and it is not checking out that way. The schematic does not show R19 going to the wiper on the pot.

Can someone confirm if either this mod is correct on the description of the "wiper to ground"?


----------



## Buggs.Crosby

i didnt keep that mod but i may have a pic of it....i'll see what i can find


----------



## Buggs.Crosby

na if i do have a pic i cant find it....i would take one but have no clue where the camera went off too


----------



## RickyLee

Buggs.Crosby said:


> i didnt keep that mod but i may have a pic of it....i'll see what i can find



You did not like that mod? I am figuring that mod needs to go with the others listed right after it in the beginning of this thread to give the best results?

I have only made up my mind to reduce the first gain stage cathode bypass cap down to 1uF or maybe even .68uF. Other than that, I am on the fence. I figured that the V1A cathode bypass cap value lowered is a good enough starting point for me. I already have the Ultra channel C12 bright cap snipped as well. My DSL100 is quite dark on both channels already.

I am figuring tweaking the Clean channel might be something I should do as well. Something along the lines of RJohns & JCMJMP's mod ideas for starters . . .

I should add that I will put a 3H choke in it as well.


----------



## Buggs.Crosby

it's not that i didnt like it as much as it made no change or at none that my ears heard.....but again the mods i have done are quite different than most of what is posted and that could be why

i think i went lower than 1uF on the bypass cap but i cant remember what value off the top of my head


----------



## Buggs.Crosby

in fact the only one from the original post was clipping the bright cap on the ultra.....but i barely even use that channel anymore......All crunch and no need for a boost......I basically went in another direction than Twin did. Gain wise my crunch is like your lead 1 with just a tad less gain but voiced closer to the 59ri i had


----------



## Landshark

Alright. Something I and a few others have noticed is the lack of cut through the whole band mix with the mods from the first page when done to the TSL except for the 1 Meg on VR3). I read a couple areas a while back... a long while back (I read through all 20 pages) and I'm currently using the mid shift as a mid boost on the lead channel. Where would I begin to start adding more mids to the lead channel without having to use the mid shift? The crunch channel doesn't need the boost, it has plenty of mids and also has a considerable amount of more bass. I'm hoping I can voice the lead channel to sound more like the crunch channel, without changing the crunch channel... where would I begin?

Also the clean channel is no where near as loud as the crunch and lead channels. How can this be remedied?

Here's my mods so far:


front board:
C12 removed
R20 jumped 
C10 .0022 uf 
C8 .001 uf

main board:
C12 1uf 63V
R30 220K 
C9 1000pf (.001uf)
Choke installed


----------



## chuckharmonjr

I just want to throw a big shout out and a huge thank you to the guys that have contributed to this thread. Twin, Joey, JCM, Jon, Lane, Buggs...everybody.....thank you very much. I have learned a ton, applied a few pounds of that...and my DSL sounds so much better now. I have a 2203 on red 1, a 900DR or MK III on red 2 and a Plexi/Super Lead on Green Crunch...all without pedals in the front end. Adding a boost is like icing on the cake on all 3. Thanks guys.


----------



## TwinACStacks

chuckharmonjr said:


> I just want to throw a big shout out and a huge thank you to the guys that have contributed to this thread. Twin, Joey, JCM, Jon, Lane, Buggs...everybody.....thank you very much. I have learned a ton, applied a few pounds of that...and my DSL sounds so much better now. I have a 2203 on red 1, a 900DR or MK III on red 2 and a Plexi/Super Lead on Green Crunch...all without pedals in the front end. Adding a boost is like icing on the cake on all 3. Thanks guys.



No thanx necessary Chuck. I do it 'cause I love British Amps and helping folks where I can with my limited Tech-ing ability. It's the REAL techs on Here Like Joey, Jon, Lane, jcmjmp, and many others that deserve the props.

 TWIN


----------



## Landshark

I also want to thank everyone on this thread for the knowledge and tinkering it took to make it what it is! Proud to be a part of the greatest forum known to man! I know I complain about it from time to time but it is by far my favorite site (only rivalled by Facebook of course). Top knotch my friends.

In other news...

Got my clean channel back! Took R30 on the main board back to stock (470K) and it is every bit as pristine as I remembered... Now if I can add more bass and mids to the lead channel to get it to sound more like the crunch I'll be in business.


----------



## jensbrix

I was just thinking, how many in here have actually done all these mods to their DSLs, and what have the outcome been in overall feel of the amp. Both the circuit changes and the tranny changes. These mods seem very tempting to try out, so I'm just a bit interested in hearing some conclusions on them.


----------



## Buggs.Crosby

jensbrix said:


> I was just thinking, how many in here have actually done all these mods to their DSLs, and what have the outcome been in overall feel of the amp. Both the circuit changes and the tranny changes. These mods seem very tempting to try out, so I'm just a bit interested in hearing some conclusions on them.



i dont have any of the mods mentioned left in my head.....but they are a bigger improvement than a tranny itself.....i used a MM fat stack OT and it is very modern sounding......if i did it again i would use one from JCM though


----------



## jensbrix

Ok  I'll be ordering parts tomorrow, looking forward to work with it


----------



## surface54

ive just put the stock 470pf c12 value back in i already feel it makes my ears feel better about it. 100pf really does make it have a more lo-fi vintage sound to the lead channels and more classic rock (i have no classic rock in me), lead2 was almost completely unusable after time, lead2 @3.5 gain was the only sweet spot and nothing else. lead1 was fine and a little smoother, but i already thought it was smooth before. my days modding are over, too stressful and unless something breaks i have no reason to alter the stock dsl tone. its actually quite great stock. i got sucked into the c12 movement, not for me.


----------



## StootMonster

Mine just has some JJ's in it. I love the sound. Not quite giving me "that sound" yet, but I'm getting closer every day.


----------



## cylon185

Awesome thread... just put my hand on a second hand DSL.


----------



## Major Sparky

This has probably already been answered. It might have even said it in the OP, but do any of these mods work for the DSL 401?


----------



## chadjwil

Yup. 
Just be sure of the board revisions before you start. Some revisions have components numbered differently. Check page 1 of this thread for the issue number of the boards that the OP is referring to, get that schematic and locate all the parts you plan to tinker with, then get the schematic for your board and make sure that the components in question are numbered the same. If not then you'll just need to make sure that you are tweaking the component that is in the same circuit location of the original drawing (again from page 1) regradless of naming convention.

Good luck


----------



## Salsg

I remember on that "other" Marshall forum that is no longer around, there was a mod to lower the bass on the green channel. I think it was one resistor.

Does anyone remember or know what that was? I would like to lower the bass on the green by a little, it is unbalanced with the red channel.


----------



## jcmjmp

Salsg said:


> I remember on that "other" Marshall forum that is no longer around, there was a mod to lower the bass on the green channel. I think it was one resistor.
> 
> Does anyone remember or know what that was? I would like to lower the bass on the green by a little, it is unbalanced with the red channel.



*One thing you can do to balance everything out is to change the cathode cap on V1a to a 1uf to 0.68uf cap. That will even things out a little. This is on the tube board.

On the front board, for the
Clean Channel: Try a different value for R3. It will take a large value to make a difference here. Try 47kΩ
Crunch Channel: Try a different value for C8. Try something like 0.001uf (1nf).*


----------



## Jchop76

hello

New here been reading over this post on modding the dsl 100. i have an older dsl 97 model that i eventually changed the main power board for a newer one. As i was hit with a bad bias drift. Tried changing everything that was suggested but nothing helped. The new board I do notice seems to be made of a different material. It looks different and the circuit is a little different. It does appear they have corrected the Grid blockers from 220K to 5K6. The bias is stable now. 

I've also installed a Marstran 100w OT and a 3H choke. the only other mod I've done was to lower the value of C12 (treble bleed) on the input board. This did lower the top high end and thickened the tone some. I've also removed the reverb board and unit as I never used reverb.

I've always like the sound of the dsl but as member TwinACStacks mentioned not the fizz. 

What Mods should I start with to get rid of the upper fizz In OD 1 and 2 . I want to lower the gain some as well. From reading this post I'm kinda wanting the same thing TwinACStacks was wanting. I never run my gain above 12 on OD 1 and 2 in the stock form it was just to much. 

I play Gisbon Les Pauls with Rio Grande BBq set, and a Epi elitist with stock pickups.

On the green crunch I like the crunch but it seemed to beefy or farty in the low end.

I like the Green clean don't really want to mess with it unless it could get cleaner, but it seems to be fine in stock form.

I'm wanting a more open and harmonic crunch. More AC/DC, Thin Lizzy sound. Less Fizzy. what should I start with? 

thanks any input would be great.


----------



## Buggs.Crosby

Try dropping R13 on the tube board down to around 100k


----------



## Jchop76

I assume you referring to my post Buggs.Crosby?

if so. I notice mention of C12 on the Main valve board as well. will this help?

what would be best mods to start with to achieve what I'm wanting? in what order?


start with?

C12 4.7uf change to a 1uf
R13 220K change to a 100K


----------



## Jchop76

I'm having a hard time sourcing the parts for this Joey mod. I've only been able to find one part in stock at Mouser. 

C12 1uf 63v WIMA that was suggested. 
Is it important to go with the WIMA caps in C12 on main valve board and C9?



Anyone know a source? what type of capacitor and resistors? Polyester film? metal film? what brands are best to go with? any help would be great. It would be helpful to include this in the mod description of suggested caps and resistors material tolerance ect.


----------



## jcmjmp

Jchop76 said:


> I'm having a hard time sourcing the parts for this Joey mod. I've only been able to find one part in stock at Mouser.
> 
> Anyone know a source? what type of capacitor and resistors? Polyester film? metal film? what brands are best to go with? any help would be great. It would be helpful to include this in the mod description of suggested caps and resistors material tolerance ect.



for the caps, I use the Wima caps as Joey suggested but also like the Vishay MKT 368 series. 

For resistors, metal film types are my favorites. Don't overthink it though.


----------



## Jchop76

jcmjmp said:


> for the caps, I use the Wima caps as Joey suggested but also like the Vishay MKT 368 series.
> 
> For resistors, metal film types are my favorites. Don't overthink it though.



having a hard time finding C9 1000pf (.001uf) 630v for the valve board. can't find a WIMA, and I don't need a minimum order of 3000. lol! 

any idea where to find one possible other brand?


----------



## Jchop76

having a hard time finding C9 1000pf (.001uf) 630v for the valve board. can't find a WIMA, and I don't need a minimum order of 3000 from germany. lol! 

any idea where to find one? possible other brands that would work for this application?


----------



## jcmjmp

Jchop76 said:


> having a hard time finding C9 1000pf (.001uf) 630v for the valve board. can't find a WIMA, and I don't need a minimum order of 3000 from germany. lol!
> 
> any idea where to find one? possible other brands that would work for this application?


Like I said, don't worry about the brand too much. Get what you can find, especially for the 630v cap.


----------



## Jchop76

ya just having a hard time in general finding a 630v cap.

so a silver mica would be okay?

what wattage on the metal film resistors? for R13, R30 on main valve board?

and R12 on the front board?


----------



## chuckharmonjr

For that matter, if you can't find a 630v rated one, get a 1000v one. like I did.


----------



## Jchop76

chuck you have a source for the 1000v?


----------



## chuckharmonjr

found it at a local supply store here in mobile


----------



## Buggs.Crosby

Jchop76 said:


> having a hard time finding C9 1000pf (.001uf) 630v for the valve board. can't find a WIMA, and I don't need a minimum order of 3000 from germany. lol!
> 
> any idea where to find one? possible other brands that would work for this application?



MKP2J011001B00JSSD WIMA Polypropylene Film Capacitors


----------



## Jchop76

ya that one is back ordered until Sept if you look. not in stock. 

I've found a couple others. 

Either A Mallory .001uf 630v or a Xicon polypropylene .001uf 630v

would either of these caps work for C9?


----------



## Joey Voltage

Jchop76 said:


> ya that one is back ordered until Sept if you look. not in stock.
> 
> I've found a couple others.
> 
> Either A Mallory .001uf 630v or a Xicon polypropylene .001uf 630v
> 
> would either of these caps work for C9?



Yikes! doesn't really matter all that much, I spec'd the wimas because I lika da reda collah!, and more importantly they have the correct lead spacing, which is the most important part. any poly cap, or what ever you want to use with a 5mm pcm is what you want. they have several film caps that fit the bill, and may other types that do too.


----------



## Jchop76

thanks Joey

I'm excited to try your mods. I've been visiting this site for a long time. this caught my interest and I finally signed up.

looking forward to hearing how this mods will affect the dsl 100


----------



## cylon185

Hey

Is it C12 on the tube board?
Thought it was C12 on the front board...


----------



## Buggs.Crosby

cylon185 said:


> Hey
> 
> Is it C12 on the tube board?
> Thought it was C12 on the front board...



There are more than 1 C12's in these amps.....each board starts fresh
C12 on the pot board is the treble bleed cap
C12 on the tube board is the cathode cap on V1


----------



## Jchop76

+1 what Buggs said.


----------



## RickyLee

OK!!

I finally got on the Bandwagon that is owning a Modded DSL!

I did not go that crazy, but the few things I did to this amp made a huge difference. I put the Mercury 3H choke in it. I am sure that had a huge impact when I had this thing cranked up a few hours ago. Now I did these mods all at the same time, so I have no idea what impact each one had overall. 

I basically just did a few of the mods at the beginning of this thread. Lowering the first gain stage cathode bypass cap is a big improvement for sure. And lowered the first gain stage plate resistor to 150K. I snipped out the Ultra channel bright cap C12 as well.

The only bitch I have left is the Clean channel. It still is not too clean, and is quite bassy/boomy. I had already lowered the value of C2 on the front control board down to .018uF but I am not sure if I am hearing any change there. And that leads me to a question of what exactly is the purpose of this cap in this part of the circuit? And what does higher/lower values achieve? This part of the circuit I am having a hard time understanding. SW1b is going to Ground/negative and the schematic is shown in the Clean mode state, correct? So then will a higher value cap in C2 bleed off/pass more high frequencies to Ground, making the clean channel bassier?






jcmjmp said:


> *One thing you can do to balance everything out is to change the cathode cap on V1a to a 1uf to 0.68uf cap. That will even things out a little. This is on the tube board.
> 
> On the front board, for the
> Clean Channel: Try a different value for R3. It will take a large value to make a difference here. Try 47kΩ
> Crunch Channel: Try a different value for C8. Try something like 0.001uf (1nf).*



Lowering the value of the huge 1MEG R3 will let more signal to Ground making the Clean channel cleaner? How will this effect the Highs and Lows?


----------



## RickyLee

I should add I am also wondering how I might have altered my Crunch channel when I lowered C2 from .047uF to .018uF?

If lowering the value of R3 cleans up the clean channel, then those frequencies will also slightly bleed off when on the Crunch channel I am figuring . . .


----------



## Jchop76

I believe I read you can mess with the value of R30 on the tube board(main board) which will affect both channels but you can reduce to clean up the fizzy and it will also clean the clean channel more. 

Also C8 if I believe will only affect the clean channel. seems like I read a post from Twin talking about this. read back through this thread to be certain.

I'm wanting to do the same thing. I don't want to lose the clean channel, but want to clean up and reduce the fizz and the gain in od1 and 2 and decrease the boomy bass in the clean green crunch.


----------



## jcmjmp

Jchop76 said:


> Also C8 if I believe will only affect the clean channel. seems like I read a post from Twin talking about this. read back through this thread to be certain.



No, C8, on the front board (with all the pots) only affects the green "crunch" mode.


----------



## RickyLee

Can any of the experts with a good understanding of theory and high pass low pass filters tell me if I made a mistake by lowering the value of the front boards C2 from .047uF to .018uF with the hope of a bit cleaner Clean mode with a bit less low frequency boominess?


----------



## jcmjmp

RickyLee said:


> Can any of the experts with a good understanding of theory and high pass low pass filters tell me if I made a mistake by lowering the value of the front boards C2 from .047uF to .018uF with the hope of a bit cleaner Clean mode with a bit less low frequency boominess?



In my opinion, changing C2 is not the way to go. C2/R2 already bleed off some of the bass @ 338Hz and under to ground.


----------



## Jchop76

jcmjmp said:


> No, C8, on the front board (with all the pots) only affects the green "crunch" mode.




That's right only crunch on the green channel.


----------



## RickyLee

jcmjmp said:


> In my opinion, changing C2 is not the way to go. C2/R2 already bleed off some of the bass @ 338Hz and under to ground.



So then my changing C2 from .047uF to .018uF was backwards? As in now I am bleeding off less bass than before?


----------



## jcmjmp

RickyLee said:


> So then my changing C2 from .047uF to .018uF was backwards? As in now I am bleeding off less bass than before?



No, you're kinda right but with the bleed off @ 338, there's no reason to move the bass shelving up.


----------



## Frankie

Okay, I just did everything in the first section except C12 (couldn't find one locally) and R30 (the amp doesn't seem too dark to me). It busts ass, especially lead 2 now, that shit is tighter than a 10 year old. I also like green crunch not being boomy as fuck now. The channels are more even sounding on the bottom end, with green being less compressed and more airy while the red channel being midsy and hot. I like! The red channel also has a lot less sizzle now, so lead 2 is usable.


----------



## Jchop76

Frankie said:


> Okay, I just did everything in the first section except C12 (couldn't find one locally) and R30 (the amp doesn't seem too dark to me). It busts ass, especially lead 2 now, that shit is tighter than a 10 year old. I also like green crunch not being boomy as fuck now. The channels are more even sounding on the bottom end, with green being less compressed and more airy while the red channel being midsy and hot. I like! The red channel also has a lot less sizzle now, so lead 2 is usable.





What mods exactly did you do? you didn't do C12? C12 on the main Tube board or C12 on the Pot front board?

And how is your green clean channel? Has it been changed any? Does it still sound clean? I don't want to lose my Green clean. But what you describe sounds good.


----------



## TwinACStacks

Frankie said:


> Okay, I just did everything in the first section except C12 (couldn't find one locally) and R30 (the amp doesn't seem too dark to me). It busts ass, especially lead 2 now, that shit is tighter than a 10 year old. I also like green crunch not being boomy as fuck now. The channels are more even sounding on the bottom end, with green being less compressed and more airy while the red channel being midsy and hot. I like! The red channel also has a lot less sizzle now, so lead 2 is usable.



Now Frankie Throw in a Choke and a C1998 (PLEXI) Output Xformer Clone from Marstran or maybe one of Joey Voltages new Universal 100W OT's from Magnetic components and be Prepared. 

One of JCMJMP's Lydian PTs will finsih the Job off. Generally PT's don't make that much difference, but in the DSL , since it's pathetically under-powered, the Lydian was night/Day.

I wouldn't steer you wrong Frankie.

 TWIN


----------



## Joey Voltage

TwinACStacks said:


> Now Frankie Throw in a Choke and a C1998 (PLEXI) Output Xformer Clone from Marstran or maybe one of Joey Voltages new Universal 100W OT's from Magnetic components and be Prepared.
> 
> One of JCMJMP's Lydian PTs will finsih the Job off. Generally PT's don't make that much difference, but in the DSL , since it's pathetically under-powered, the Lydian was night/Day.
> 
> I wouldn't steer you wrong Frankie.
> 
> TWIN



I MUST BREAK YOU





Left is the Mag Comp 18072, and Right is the Marstran. I didn't take this picture, the credit goes to a fellow board member here; gldtp99


----------



## TwinACStacks

Joey Voltage said:


> I MUST BREAK YOU
> 
> 
> 
> 
> 
> Left is the Mag Comp 18072, and Right is the Marstran. I didn't take this picture, the credit goes to a fellow board member here; gldtp99



Man Joey, That's gotta be a HUGE tranny. As you know I dropped in a real C1998 out of a Plexi I bought on Fleabay and IT was large. That OT must be Gigantic. Is It Taller or just thicker?

 TWIN


----------



## Joey Voltage

TwinACStacks said:


> Man Joey, That's gotta be a HUGE tranny. As you know I dropped in a real C1998 out of a Plexi I bought on Fleabay and IT was large. That OT must be Gigantic. Is It Taller or just thicker?
> 
> TWIN



Well it's not as big as Rupaul........ It just has a thicker lamination stack than the Marstran, same height


----------



## TwinACStacks

Joey Voltage said:


> Well it's not as big as Rupaul.......




Well it's still a big Tranny. Not Flaming, but large.

 TWIN


----------



## Jchop76

Okay I completed these mods on my 100 watt dsl

Main board (tube Board):

C12: Changed to 1uf
C9: Changed to .001uf
R7: 5k6
R10: 5K6
R66: 5K6
R70: 5K6
R30: changed to 190K (470K+1M+470K)


Input Board (pot board)

V3: 1M resistor across wiper and Ground
C12: Removed
C10: changed to .0022uf
R20: jumpered
C8: changed to .001uf
R12: (470K) changed to 220K 

Already installed a Marstran 1998 OT and a 3H choke. Has stock power transformer


After some testing I notice the bass is tighter and less flubby. Also Gain is reduced in RED OD1 & OD2 . The gain has been slightly increased in crunch Green

I like the gain structure and less fizzy upper highs however I've noticed it seems as if the mid bark has been lost some. It's still there but complex chords with crunch has lost some definition. It's as if the mids are burried more. The freq curve for the mids seems different. 

What can I change to bring some upper mids back to OD1 and OD2? I notice Green Crunch has a little more mids. However I would like a little more mids.

where do I start?
Would putting a 100 or 220K back in C12 on the Input (pot board) bring back some mids?

taking in consideration with the mods I've done what are my options?

thanks
Jchop


----------



## TwinACStacks

JChop I eventually went to .0015uf on C8. Try that.

 TWIN


----------



## Jchop76

TwinACStacks said:


> JChop I eventually went to .0015uf on C8. Try that.
> 
> TWIN



what affect does C8 have? will this help the mids?


----------



## jcmjmp

Jchop76 said:


> what affect does C8 have? will this help the mids?



No - It changes the bass shelving frequency.


----------



## Jchop76

jcmjmp said:


> No - It changes the bass shelving frequency.



I see.

My mids seem more buried than before in both channels. how can I bring back some upper mids bark to OD1 & OD2 and on the green channel?

should I put something back in C12 on the pot board?


----------



## Buggs.Crosby

C12 wont help as it is the treble bleed cap


----------



## Buggs.Crosby

did you make sure the caps were oriented correctly?


----------



## Jchop76

Buggs.Crosby said:


> did you make sure the caps were oriented correctly?



ON the main tube board and Pot board?
I just faced them in accordance with the others on the board. what affect will this have if not oriented correctly?


----------



## Buggs.Crosby

some of the electrolytic caps yes....you might want to check all those that you replaced


----------



## Jchop76

Buggs.Crosby said:


> some of the electrolytic caps yes....you might want to check all those that you replaced



I am aware of the facing electrolytic caps correctly, but I didn't replace anything with electrolytic caps.


----------



## Buggs.Crosby

C12 should be and electro 4.7uf....but that is the only one you posted that is
the only other thing i can think of is the 1M resistor on V3.....are you sure that is right?....that is the correct pot and the correct leg (wiper) of that pot?


----------



## Jchop76

Buggs.Crosby said:


> C12 should be and electro 4.7uf....but that is the only one you posted that is
> the only other thing i can think of is the 1M resistor on V3.....are you sure that is right?....that is the correct pot and the correct leg (wiper) of that pot?



Yes you are correct C12 on the main tube board was a 4.7uf electro but it was replaced with a 1uf 63v Wima polyester film cap. To my understanding these do not have a polarity so it doesn't matter how it goes in.

Yes the 1M resistor is connected correctly on V3 as per the instructions.

As I said I like the overall feel and gain structure but the mids seem to be a little more buried than they were before, not terribly bad but the freq curve is different. 

I do notice I can not set the eq as I once did before because all the controls are different and actually work more dramatically. However, even with the mids cranked it still has to my ears lost that upper mid bark it once had. perhaps its the voicing of the mids that have changed. I do like not having that upper annoying fizz it once had. I just want some chewy organic mids back. maybe not as drastic, but It really reminds me as if the amp sounds more 6L6 type instead of EL34. 

I'm running winged -C- El34s in power and a Tung sol 12AX7 in V1, JJEcc83 in V2, V3, and a balanced JJecc83 in V4 phase.


----------



## GuN'R

I am considering adding a choke to my DSL 50. Does anyone know if this would be the correct type?

156M Hammond Manufacturing Common Mode Inductors (Chokes)


----------



## Frankie

Jchop76 said:


> Okay I completed these mods on my 100 watt dsl
> 
> Main board (tube Board):
> 
> C12: Changed to 1uf
> C9: Changed to .001uf
> R7: 5k6
> R10: 5K6
> R66: 5K6
> R70: 5K6
> R30: changed to 190K (470K+1M+470K)
> 
> 
> Input Board (pot board)
> 
> V3: 1M resistor across wiper and Ground
> C12: Removed
> C10: changed to .0022uf
> R20: jumpered
> C8: changed to .001uf
> R12: (470K) changed to 220K
> 
> Already installed a Marstran 1998 OT and a 3H choke. Has stock power transformer
> 
> 
> After some testing I notice the bass is tighter and less flubby. Also Gain is reduced in RED OD1 & OD2 . The gain has been slightly increased in crunch Green
> 
> I like the gain structure and less fizzy upper highs however I've noticed it seems as if the mid bark has been lost some. It's still there but complex chords with crunch has lost some definition. It's as if the mids are burried more. The freq curve for the mids seems different.
> 
> What can I change to bring some upper mids back to OD1 and OD2? I notice Green Crunch has a little more mids. However I would like a little more mids.
> 
> where do I start?
> Would putting a 100 or 220K back in C12 on the Input (pot board) bring back some mids?
> 
> taking in consideration with the mods I've done what are my options?
> 
> thanks
> Jchop



Lead 2 might've lost some mids because you removed C12. I put a 150pf cap there on mine and the mids are suh-weeet in Lead 2 now. With the tone down it sounds like Leslie West! I also didn't touch R12 and changed C8 to .0022uf.

On the tube board all I changed was C9 to 1000pf, nothing else as I didn't find the amp to be too dark as suggested in the OP.


----------



## TwinACStacks

You may need to tweak R30 a little to your taste, a little bit makes a lot of difference here. It also will play with the amount of fizzies.

 TWIN


----------



## Jchop76

TwinACStacks said:


> You may need to tweak R30 a little to your taste, a little bit makes a lot of difference here. It also will play with the amount of fizzies.
> 
> TWIN




IT's weird I went to test this amp again and I think I have it figured out now. maybe the new parts needed some time to settle in.
The EQ is really different so my previous settings will not work. 

Either I'm getting use to it or cranking it up to about 4-5 makes a big difference the mids seem to be there, I'm thinking it was just my settings. I'm really liking it now.

Twin on your C8 you initially said you had it at a .0015uf then later in this post a couple times mention you settled on .001uf for C8.

what did you finally settle on for C8? changing this affects the green crunch bass if it's to boomy with the bass switch in correct?


----------



## TwinACStacks

Jchop: My Bad. I just reviewed my personal notes on my experiments with the DSL, You are correct I started with .0015 then settled on .001uf.

No C8 is overall boominess.

To lessen Boominess from DEEP SWITCH

Change C29 on frontboard to 1uf no more than 2.2uf or it will get woofy. 


 TWIN


----------



## jcmjmp

TwinACStacks said:


> Jchop: My Bad. I just reviewed my personal notes on my experiments with the DSL, You are correct I started with .0015 then settled on .001uf.
> 
> No C8 is overall boominess *(In crunch mode only)*
> 
> To lessen Boominess from DEEP SWITCH
> 
> Change C29 on frontboard to 1uf no more than 2.2uf or it will get woofy.
> 
> 
> TWIN



Just added a clarification here (in bold green)


----------



## TwinACStacks

jcmjmp said:


> Just added a clarification here (in bold green)



Corrected....

 TWIN


----------



## TwinACStacks

There's a LOT of DSL love on this forum. Glad we did this JC.

 TWIN


----------



## Frankie

Switching C8 to .0022uf made my crunch channel way mo betta.


----------



## Jchop76

TwinACStacks said:


> Corrected....
> 
> TWIN




Ya the .001uf in C8 sounds good. the amps sounds super. These mods really do greatly improve this amp. No more fizzy ice pick to 
the ears.


----------



## RickyLee

Jchop76 said:


> Ya the .001uf in C8 sounds good. the amps sounds super. These mods really do greatly improve this amp. No more fizzy ice pick to
> the ears.




I was experiencing about the same thing as you the last few nights. I did some MAJOR tinkering with my DSL100 over the weekend. I was even experimenting with different values of cathode resistor values on the first three gain stages as well as with some various cathode bypass caps in a few strategic locations. By Sunday I thought I was really on to something with all my tinkering. Then I am figuring I started suffering from a bit of ear fatigue by Sunday evening as the amp started sounding a bit different in a bad way. Monday I came home from work and fired the DSL100 up again and was not impressed. Took a break from it Tuesday, then played it a bit last night but again I was saying to myself "What happened to my Mids, as well as a bit of my highs as well?"

Well tonight I fired it up again and this time I swapped the 12AX7's V1 and V3 with each other. There was a bit of life in her once again. So then I took what was in V3 that got switchewd to V1 and yanked it out completely. This tube that I got rid of was a Sovtek 12AX7LPS. And I had it in V3 for quite some time running at well over 400V on the cathode follower V3B plates. I had actually reduced my overall B+ rail voltage from the feed to the phase inverter on downstream to rest of the preamp by aprox. 100VDC last Sunday, which was the last tweak I did to it. But that LPS must have been quite exhausted running at the high voltages.

What I am getting at here is the preamp valves are quite important in this amp - even more so V3 which should be a very rugged reliable valve for sure. The 12AX7 Chinese tubes are awesome in my DSL.

Tonight I also tried my new quad of JJ KT77's one more time. But I can say I am preferring the GT EL34M over those. I originally had GT E34Ls' in there with good results as well. But I am just not feeling the KT77's in this amp. My DSL is already quite dark, so that must be most of why I am not liking the KT77's as much. But if you are looking for more Phatness, the KT77's are the way to go for sure. The EL34M's have a touch more crunchy mids than the KT77's.


----------



## Jason77

i'm really loving the mods. i haven't touched C8 or R30 yet. i have a lydian OT and choke coming and i want to see what it sounds like with those installed before i start tinkering with those components. the only thing i want to go in and play with right now is dropping C12 on the tube board from 1uf to .68uf. 1uf was a big improvement but i think i'd like a little more.

ricky... what tubes are you running in your preamp?


----------



## Jchop76

Jason77 said:


> i'm really loving the mods. i haven't touched C8 or R30 yet. i have a lydian OT and choke coming and i want to see what it sounds like with those installed before i start tinkering with those components. the only thing i want to go in and play with right now is dropping C12 on the tube board from 1uf to .68uf. 1uf was a big improvement but i think i'd like a little more.
> 
> ricky... what tubes are you running in your preamp?




I did this. Dropped C12 on the tube board from a 1uf to a .68uf..

Didn't like it. stuck the 1uf back in. but I have messed with R30.

I followed what Twin did and I really like the voicing and gain structure 100 times better in this amp. It is more versatile. From light crunch to full on heavy crunch OD. It smokes now.


----------



## Jchop76

RickyLee said:


> I was experiencing about the same thing as you the last few nights. I did some MAJOR tinkering with my DSL100 over the weekend. I was even experimenting with different values of cathode resistor values on the first three gain stages as well as with some various cathode bypass caps in a few strategic locations. By Sunday I thought I was really on to something with all my tinkering. Then I am figuring I started suffering from a bit of ear fatigue by Sunday evening as the amp started sounding a bit different in a bad way. Monday I came home from work and fired the DSL100 up again and was not impressed. Took a break from it Tuesday, then played it a bit last night but again I was saying to myself "What happened to my Mids, as well as a bit of my highs as well?"
> 
> Well tonight I fired it up again and this time I swapped the 12AX7's V1 and V3 with each other. There was a bit of life in her once again. So then I took what was in V3 that got switchewd to V1 and yanked it out completely. This tube that I got rid of was a Sovtek 12AX7LPS. And I had it in V3 for quite some time running at well over 400V on the cathode follower V3B plates. I had actually reduced my overall B+ rail voltage from the feed to the phase inverter on downstream to rest of the preamp by aprox. 100VDC last Sunday, which was the last tweak I did to it. But that LPS must have been quite exhausted running at the high voltages.
> 
> What I am getting at here is the preamp valves are quite important in this amp - even more so V3 which should be a very rugged reliable valve for sure. The 12AX7 Chinese tubes are awesome in my DSL.
> 
> Tonight I also tried my new quad of JJ KT77's one more time. But I can say I am preferring the GT EL34M over those. I originally had GT E34Ls' in there with good results as well. But I am just not feeling the KT77's in this amp. My DSL is already quite dark, so that must be most of why I am not liking the KT77's as much. But if you are looking for more Phatness, the KT77's are the way to go for sure. The EL34M's have a touch more crunchy mids than the KT77's.




Good point. I may tinker around with the preamp tubes. what chinese tubes are you using in the preamp?


----------



## TwinACStacks

I ran an EI in V1, High Gain Raytheon Blackplate in V2, V3 Grayplate Sylvania, and a High Gain Mullard in V4 With Winged "C"s in Power Section.

It Fucking Ripped. If You follow the Joey Mods like Jchop did, it makes it a DSpLexi, Kinda Vintagey. The addition of a Choke, Lydian PT and the Plexi Dagnall C1998 OT put it in another dimension entirely.

 TWIN


----------



## Frankie

I don't know if my DSL, even Joey Modded, sounds anything like a Plexi. A JCM 800 maybe, but a Plexi, nah.


----------



## Jchop76

TwinACStacks said:


> I ran an EI in V1, High Gain Raytheon Blackplate in V2, V3 Grayplate Sylvania, and a High Gain Mullard in V4 With Winged "C"s in Power Section.
> 
> It Fucking Ripped. If You follow the Joey Mods like Jchop did, it makes it a DSpLexi, Kinda Vintagey. The addition of a Choke, Lydian PT and the Plexi Dagnall C1998 OT put it in another dimension entirely.
> 
> TWIN



I can hear that. Especially if changing preamp possibly going to a 5751 in the preamp. 

Like a plexi/ 800 to hot rod 800.

I can say for certain it does more and is more versatile than a stock dsl by far. If marshall made these like this stock they would have never discontinued making them.

I might add I bought a JVM 410H not long after they come out. Those amps are over priced for what they are. It sounded like a solid state amp. It was really weird I hated it. Ended up selling it. I've had my dsl since 98. ONly thing I had to do was replace the tube board it was the old material not glass fiber. Anyways The DSL smokes the JVM hands down even more so since the mod!


----------



## TwinACStacks

Frankie said:


> I don't know if my DSL, even Joey Modded, sounds anything like a Plexi. A JCM 800 maybe, but a Plexi, nah.



Plexier Frankie. The joey mods actually DECREASE the Gain and Fizzies. I can hear 800 in it also. The secret is the C1998 Dagnall OT. If you use any other iron it won't sound the same.

 TWIN


----------



## jcmjmp

TwinACStacks said:


> Plexier Frankie. The joey mods actually DECREASE the Gain and Fizzies. I can hear 800 in it also. The secret is the C1998 Dagnall OT. If you use any other iron it won't sound the same.
> 
> TWIN



Iron will help for sure. The Lydian OT I put in mine really made a good thing better. 

Still, not plexi.


----------



## chuckharmonjr

Frankie said:


> I don't know if my DSL, even Joey Modded, sounds anything like a Plexi. A JCM 800 maybe, but a Plexi, nah.



I gotta agree with Francesco here. Joey mods plus a killer Marty pre-amp tone pack plus JJ E34L's....my DSL on green crunch is my old 2203..no doubt...on red channel...lol...totally insane


----------



## TwinACStacks

chuckharmonjr said:


> I gotta agree with Francesco here. Joey mods plus a killer Marty pre-amp tone pack plus JJ E34L's....my DSL on green crunch is my old 2203..no doubt...on red channel...lol...totally insane



Okay my fellow nit-pickers here. Exactly what amp is the 2203 a derivative of?


Clue: 19X9. Super Lead Plexi.


 TWIN


----------



## Jchop76

TwinACStacks said:


> Okay my fellow nit-pickers here. Exactly what amp is the 2203 a derivative of?
> 
> 
> Clue: 19X9. Super Lead Plexi.
> 
> 
> TWIN




isn't it basically a plexi circuit with a master volume? JMP later 2203


----------



## Buggs.Crosby

TwinACStacks said:


> Okay my fellow nit-pickers here. Exactly what amp is the 2203 a derivative of?
> 
> 
> Clue: 19X9. Super Lead Plexi.
> 
> 
> TWIN



what about us pit -nickers?


----------



## TwinACStacks

Buggs.Crosby said:


> what about us pit -nickers?



Stand Down Buggs. No one is taking off their Knickers...


 TWIN


----------



## TwinACStacks

Jchop76 said:


> isn't it basically a plexi circuit with a master volume? JMP later 2203



Kind of that too. It's really a bastard circuit meant to be very flexible.

 TWIN


----------



## RickyLee

Just got back into town from Santa Barbara. My Gal and Myself seen Incubus at the Santa Barbara Bowl. Awesome show to say the least. These guys are just an incredible band.

And for Twin: There was an AC30 on the stage. There was an AC30 on the stage.

Man, an AC30 is still on my GAS list for sure.

OK. For the questions on what valves I am running in my DSL?

I have the generic no label older Chinese 12AX7's with the square dish getters in V1 - V3. And I had put a new Electro Harmonix 12AX7 in V4 last week as this DSL ate a new JJ ECC83S up in no time at all in the phase inverter. I might pull a Mullard I61/I63 ECC83 out of my stash and try it in V1. But I am remembering I did not hear much of a difference with certain NOS valves compared to new production 12AX7's. So I did not have the urge to burn any in my DSL for that reason. But that was before I did all this work to it. 

My DSL B+ voltages were all close to 300V on all the preamp plates, and 430V/230V on my cathode follower. So that would be a good reason to use a good robust NOS valve in V3. I knocked all my preamp B+ voltages down by aprox, 100V last weekend though.

I am thinking about replacing my output transformer as well. But the price of the Mercury DSL100 upgrade is absurd. What would be the best cost effective upgrade to these stock Dagnalls?

And is there a power transformer upgrade that puts out at least an additional 10V or more on the bias supply windings compared to the stock Dagnall?


----------



## Jchop76

RickyLee said:


> Just got back into town from Santa Barbara. My Gal and Myself seen Incubus at the Santa Barbara Bowl. Awesome show to say the least. These guys are just an incredible band.
> 
> And for Twin: There was an AC30 on the stage. There was an AC30 on the stage.
> 
> Man, an AC30 is still on my GAS list for sure.
> 
> OK. For the questions on what valves I am running in my DSL?
> 
> I have the generic no label older Chinese 12AX7's with the square dish getters in V1 - V3. And I had put a new Electro Harmonix 12AX7 in V4 last week as this DSL ate a new JJ ECC83S up in no time at all in the phase inverter. I might pull a Mullard I61/I63 ECC83 out of my stash and try it in V1. But I am remembering I did not hear much of a difference with certain NOS valves compared to new production 12AX7's. So I did not have the urge to burn any in my DSL for that reason. But that was before I did all this work to it.
> 
> My DSL B+ voltages were all close to 300V on all the preamp plates, and 430V/230V on my cathode follower. So that would be a good reason to use a good robust NOS valve in V3. I knocked all my preamp B+ voltages down by aprox, 100V last weekend though.
> 
> I am thinking about replacing my output transformer as well. But the price of the Mercury DSL100 upgrade is absurd. What would be the best cost effective upgrade to these stock Dagnalls?
> 
> And is there a power transformer upgrade that puts out at least an additional 10V or more on the bias supply windings compared to the stock Dagnall?





Seriously get a Marstran C1998 it is killer! Period. Enough said.

Made a huge difference in the amp. Like Twin has said I think you will be surprised. get a 3H choke. If you don't have the money for it save for it... Anything else well... will be just okay.. my 2 cents..

I've yet to change my Power transformer but I if I do I'm going with one from the member here JCM


----------



## Jchop76

chuckharmonjr said:


> I gotta agree with Francesco here. Joey mods plus a killer Marty pre-amp tone pack plus JJ E34L's....my DSL on green crunch is my old 2203..no doubt...on red channel...lol...totally insane



Try some Winge =C= EL34's I never really cared to much for JJE34L's They always seem to not last very long and wen noisy to soon. I went through two sets from Euro Tubes and they were garbage. They were also not matched very well..


----------



## jcmjmp

RickyLee said:


> I am thinking about replacing my output transformer as well. But the price of the Mercury DSL100 upgrade is absurd. What would be the best cost effective upgrade to these stock Dagnalls?
> And is there a power transformer upgrade that puts out at least an additional 10V or more on the bias supply windings compared to the stock Dagnall?



I offer both a power and output transformer upgrade, specifically designed for the DSL and my prices are very reasonable + you get a top quality, paper interleaved transformer that will really make your amp better.
The OT I offer is basically a plexi transformer in a DSL form factor. 
Marshall DSL Transformers


----------



## Frankie

TwinACStacks said:


> Okay my fellow nit-pickers here. Exactly what amp is the 2203 a derivative of?
> 
> 
> Clue: 19X9. Super Lead Plexi.
> 
> 
> TWIN




Based on that logic my DSL could also "sound like a bassman" right? The green crunch channel is in the realm of my 2203, but not really like my 1987. I need to just get some damn clips recorded.


----------



## RickyLee

jcmjmp said:


> I offer both a power and output transformer upgrade, specifically designed for the DSL and my prices are very reasonable + you get a top quality, paper interleaved transformer that will really make your amp better.
> The OT I offer is basically a plexi transformer in a DSL form factor.
> Marshall DSL Transformers



The prices are reasonable for sure. I will kick it around on picking up an output transformer.

As for the power transformer, if I could get a reduction in overall HT/B+ voltage by at least 20VDC on my secondary, I would be extremely happy to make a purchase there. Oh yes, I would like to get a few more volts out of the bias supply windings as well.

Now that I am on a roll here, someone needs to come up with a power transformer designed for people that are living with the higher 125VAC MAINS from there Electrical service providers. That is the problem for me on all my gear usually. And even with the DSL100, I will sometimes see my heater filament supply at 6.9V.


----------



## TwinACStacks

Jchop76 said:


> Seriously get a Marstran C1998 it is killer! Period. Enough said.
> 
> Made a huge difference in the amp. Like Twin has said I think you will be surprised. get a 3H choke. If you don't have the money for it save for it... Anything else well... will be just okay.. my 2 cents..
> 
> I've yet to change my Power transformer but I if I do I'm going with one from the member here JCM



JChop I'm very happy to say it sounds like you are following the Joey mods EXACTLY.

Good Boy. The others that have changed the formula, (even slightly), won't get the same results..... That's why some of them are left scratching their asses trying to figure out what happened to their Mid's or Bass.

Twin did a LOT of experimenting with different components, and a Lot of consultation with various Marshall Forum Techs _*Before*_ he made the Thread. It wasn't a Guess.

 TWIN


----------



## TwinACStacks

Frankie said:


> Based on that logic my DSL could also "sound like a bassman" right? The green crunch channel is in the realm of my 2203, but not really like my 1987. I need to just get some damn clips recorded.



Did You follow ALL the Joey Mods *EXACTLY?* Including the SPECIFIC Values and Transformers without deviation from the FORMULA?

 TWIN


----------



## Frankie

TwinACStacks said:


> Did You follow ALL the Joey Mods *EXACTLY?* Including the SPECIFIC Values and Transformers without deviation from the FORMULA?
> 
> TWIN



Shit no. I already got a Plexi, so I wanted my DSL to sound hotter than the sun. No point in owning a bunch of amps that sound the same, naaameen? I actually did some additional mods above and beyond the Joey Mods and the shit sounds real good!


----------



## Buggs.Crosby

Frankie said:


> Shit no. I already got a Plexi, so I wanted my DSL to sound hotter than the sun. No point in owning a bunch of amps that sound the same, naaameen? I actually did some additional mods above and beyond the Joey Mods and the shit sounds real good!



Yes.....Yes they do


----------



## TwinACStacks

Frankie said:


> Shit no. I already got a Plexi, so I wanted my DSL to sound hotter than the sun. No point in owning a bunch of amps that sound the same, naaameen? I actually did some additional mods above and beyond the Joey Mods and the shit sounds real good!



Yes...Yes they Do. I specifically was after UN-Modernizing the DSL a Tad. But you can go the other way too Like Buggs did. There is no right or wrong, it's an extremely versatile modding platform. Personally I think it's the best Marshall for modding.

 TWIN


----------



## Frankie

It's one of the best Marshalls period as far as I'm concerned. I did some of Bugg's mod to the green channel and some of the Joey mods to the red channel. Now I have two ball busting channels. I've been calling it the DSLaidoff 'cause it's gonna get me fired from my band.


----------



## TwinACStacks

Frankie said:


> It's one of the best Marshalls period as far as I'm concerned. I did some of Bugg's mod to the green channel and some of the Joey mods to the red channel. Now I have two ball busting channels. I've been calling it the DSLaidoff 'cause it's gonna get me fired from my band.



Just tell them The Guys at the Marshall Forum just told them to turn their wimpy-assed Amps up a little to keep up....

 TWIN


----------



## Frankie

TwinACStacks said:


> Just tell them The Guys at the Marshall Forum just told them to turn their wimpy-assed Amps up a little to keep up....
> 
> TWIN



They did! I'm competing with a 2203 and an SVT, so it's not like they can't keep up, the problem is that they did. It was so loud Thumper had to put in ear plugs and beat the shit out of his drums just to keep up.


----------



## Buggs.Crosby




----------



## RickyLee

Hey Twin;

Did you see my post about Incubus having an AC30 on stage last night?

And another question for you Twin. How would you compare your Ampeg V4 to the DSL when you had it on overall volume/loudness? 

I have to say my DSL100 is actually louder than my Ampeg V4 (yes my Ampeg has new filter caps). My DSL Crunch channel actually sounds almost identical to my '83 2204 now after all the work I did to the DSL100.


----------



## TwinACStacks

RickyLee said:


> Hey Twin;
> 
> Did you see my post about Incubus having an AC30 on stage last night?
> 
> And another question for you Twin. How would you compare your Ampeg V4 to the DSL when you had it on overall volume/loudness?
> 
> I have to say my DSL100 is actually louder than my Ampeg V4 (yes my Ampeg has new filter caps). My DSL Crunch channel actually sounds almost identical to my '83 2204 now after all the work I did to the DSL100.



 Ricky that doesn't sound right at all. My V4 was WAY louder than any Marshall I've ever owned, by a ways, not by a small margin.

I don't know what to tell you.

 TWIN


----------



## TwinACStacks

Frankie said:


> They did! I'm competing with a 2203 and an SVT, so it's not like they can't keep up, the problem is that they did. It was so loud Thumper had to put in ear plugs and beat the shit out of his drums just to keep up.



Now You guys are Cookin'....

 TWIN


----------



## Frankie

RickyLee said:


> Hey Twin;
> 
> Did you see my post about Incubus having an AC30 on stage last night?
> 
> And another question for you Twin. How would you compare your Ampeg V4 to the DSL when you had it on overall volume/loudness?
> 
> I have to say my DSL100 is actually louder than my Ampeg V4 (yes my Ampeg has new filter caps). My DSL Crunch channel actually sounds almost identical to my '83 2204 now after all the work I did to the DSL100.





TwinACStacks said:


> Ricky that doesn't sound right at all. My V4 was WAY louder than any Marshall I've ever owned, by a ways, not by a small margin.
> 
> I don't know what to tell you.
> 
> TWIN



For real! Forge used to have a V4 so I put it on one of my Marshall cabinets once and cranked a guitar through it. Holy fucking shit it was loud and I had a Hot Plate on it! The DSL is real loud, don't get me wrong, but a V4 is pretty retarded.



TwinACStacks said:


> Now You guys are Cookin'....
> 
> TWIN



We're not playing around, sir.


----------



## TwinACStacks

Frankie said:


> For real! Forge used to have a V4 so I put it on one of my Marshall cabinets once and cranked a guitar through it. Holy fucking shit it was loud and I had a Hot Plate on it! The DSL is real loud, don't get me wrong, but a V4 is pretty retarded.
> 
> 
> 
> We're not playing around, sir.



I had NO Doubt at all Frankie.

 TWIN


----------



## TwinACStacks

Ricky Frankie is right. They are Retarded Loud.

How do you think I got the way I am?

 TWIN


----------



## gibson22

looking for some info? I have a marshell jcm 2000 dsl 100" is it good to use a fan behind your amp to help keep it cool.


----------



## chuckharmonjr

Just like your car engine, tube amps need to run at a certain temperature to work right and be efficient. Thats why there are heater filaments in each tube. What makes you think you might need a fan?


----------



## TwinACStacks

chuckharmonjr said:


> Just like your car engine, tube amps need to run at a certain temperature to work right and be efficient. Thats why there are heater filaments in each tube. What makes you think you might need a fan?



My guess would be the Melted Air vent....

 TWIN


----------



## RickyLee

LOL.

I turned both volumes on the DSL100 to 10 and tinkered with it like a non master volume . . .










Yes the V4 is extremely loud as well. But the V4 starting getting Dirty and breaking up just before the level I could safely climb the DSL to. This was through a 4X12 cab. 

Trust me - windows were shakin' for both of these bad boys.

We were Shakin', Woo ooh ooh oh oh . . .


----------



## gibson22

well yesterday my amp just cut out no sound .Thought that it got hot and would need a fan to help keep it cool.. today I went out and looked at it and saw that my HT-fuse was blown. will radio shake have one .thanks for the reply.


----------



## TwinACStacks

RickyLee said:


> LOL.
> 
> I turned both volumes on the DSL100 to 10 and tinkered with it like a non master volume . . .
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Yes the V4 is extremely loud as well. But the V4 starting getting Dirty and breaking up just before the level I could safely climb the DSL to. This was through a 4X12 cab.
> 
> Trust me - windows were shakin' for both of these bad boys.
> 
> We were Shakin', Woo ooh ooh oh oh . . .



 I'm still thinking something ain't right. Unless I set the EQ and Switches for "Marshall tone"--I downloaded the Manual, On Clean it would be Deafening before it even HINTED at breaking up. And I MEAN WAY LOUDER than a DSL is capable of on 10.

Mine was a 1976 non Distortion model.






 TWIN


----------



## rockgod212

im revoicing my dsl100 again, can someone explain to me what stages are used on the green crunch channel and which stages are on the red lead channels? 

what does the diode circuitry at the imput on the pot board do, are they really needed, as i would like to remove them if possible?


----------



## jcmjmp

rockgod212 said:


> what does the diode circuitry at the imput on the pot board do, are they really needed, as i would like to remove them if possible?



The diode on the input prevents overvoltages making it into the amp.


----------



## rockgod212

question......on the pot board, i know c12 and c13 are the brite caps for the red lead channel, but how do they work together, series or parallell? is c12 for lead 1, and c12+c13 for lead 2.......trying to find the right values, but a bit confused as to how they work together.........


----------



## rockgod212

ok i think i understand c12 and c13, am i correct to say that c12 is the brite cap and c13 goes from the gain pot wiper to ground when switched to lead2?


----------



## Jchop76

jcmjmp said:


> I offer both a power and output transformer upgrade, specifically designed for the DSL and my prices are very reasonable + you get a top quality, paper interleaved transformer that will really make your amp better.
> The OT I offer is basically a plexi transformer in a DSL form factor.
> Marshall DSL Transformers



Hey JCM. I'm interested in your power transformer for the DSL 100. You only list one. Do you offer two different Power Transformers for the dsl? a 50watt and a 100watt?

I have a dsl 100.


----------



## jcmjmp

Jchop76 said:


> Hey JCM. I'm interested in your power transformer for the DSL 100. You only list one. Do you offer two different Power Transformers for the dsl? a 50watt and a 100watt?
> 
> I have a dsl 100.



The power transformers are basically the same part number. The 100w PT is the one I use for the 50w. Both have much better characteristics than the stock transformers both in terms of power delivery and noise.


----------



## chuckharmonjr

Twin...you smartass...remind me to fly to Detroit and piss on some rock salt in your front yard...lol...ya think he might have red-plated a tube or two?...lol


----------



## valvehead

hi guys---
Ive been trying some of these mods on a DSL here.

It does sound a little better. I really like whats going on with LEAD 1 on mine tone wise ....BUT , if i could get a little more gain out of it--it would be perfect.

LEAD 2 does have more gain , but its a little mushy--when you chunk on some chords--as in palm muting. Its just not "tight " enough for my taste .

So, which exact resistors can i play with to get a little bit more gain on LEAD 1 ?
and will that affect Lead 2 ?


----------



## TwinACStacks

A choke and OT will tighten it up considerably. Then add JC's Lydian PT to the mix and it becomes tighter than a frog's waterproof butthole.

 TWIN


----------



## SHV

test


----------



## valvehead

TwinACStacks said:


> A choke and OT will tighten it up considerably. Then add JC's Lydian PT to the mix and it becomes tighter than a frog's waterproof butthole.
> 
> TWIN





responding to my post?

if so---i disagree. A choke wont really "tighten" up an amp. Its more of an inductor --or filter for ac . Example----5150 has no choke ==very tight and chunky amp. NOW--I have NOT tried a choke IN A DSL----so i could be wrong in that case 

In my experiences---A power transformer will not affect an amp as far as tone or tightness. UNLESS--you have a weak or malfunctioning power trans that is not delivering proper current/ voltage.

OT-----Ive installed many of them in many amps, The WAY overpriced Mercury , etc....I did not hear any difference--nor did the amp owners. Yes they are a better quality OT. Tone ? no. Go with a Heyboer.

Im just not that familiar with the DSL--especially when the dam schematic takes off to " CON3" , CON14 , etc....  Just wondering where lead 1 stuff can be adjusted----- just asking in case a couple of you have done exactly what im talking about ---you dig ? 

or maybe i shall dig into the schem.


----------



## TwinACStacks

valvehead said:


> responding to my post?
> 
> if so---i disagree. A choke wont really "tighten" up an amp. Its more of an inductor --or filter for ac . Example----5150 has no choke ==very tight and chunky amp. NOW--I have NOT tried a choke IN A DSL----so i could be wrong in that case
> 
> In my experiences---A power transformer will not affect an amp as far as tone or tightness. UNLESS--you have a weak or malfunctioning power trans that is not delivering proper current/ voltage.
> 
> OT-----Ive installed many of them in many amps, The WAY overpriced Mercury , etc....I did not hear any difference--nor did the amp owners. Yes they are a better quality OT. Tone ? no. Go with a Heyboer.
> 
> Im just not that familiar with the DSL--especially when the dam schematic takes off to " CON3" , CON14 , etc....  Just wondering where lead 1 stuff can be adjusted----- just asking in case a couple of you have done exactly what im talking about ---you dig ?
> 
> or maybe i shall dig into the schem.



The Stock xformers in the DSL are pitifully Under-Speced. JC's are made by Heyboer. Trust me, we aren't dummies on what will work in a DSL. Personally I like the Plexi Dagnall C1998 OT made by Marstran. I noticed a considerable bit of tightness added to the Bottom end with the choke/OT combination, Of Course I was tweaking the internals at the same time... JC or Joey could get more specific, I know playing with the Value on C10 on the frontboard can tighten Lead 2 a Tad. Adjusting the Value of R30 on the Tubeboard drastically affects Overall Gain and brightness of both Channels.

 TWIN


----------



## jcmjmp

valvehead said:


> responding to my post?
> 
> if so---i disagree. A choke wont really "tighten" up an amp. Its more of an inductor --or filter for ac . Example----5150 has no choke ==very tight and chunky amp. NOW--I have NOT tried a choke IN A DSL----so i could be wrong in that case



Listen... you've got some knowledgeable techs and hobbyists here giving you advice and stating facts. Perhaps you should research/learn before you post stuff like the above. 

A choke will contribute to the overall tighness of a tube amp because it reduces the amount of voltage sag vs using a resistor and if you select your choke wisely, it can also increase screen voltage which can have a slight effect on headroom of the amp. 

This applies to most class AB amps. It has been done on the 5150 FYI and it does make a difference

http://www.marshallforum.com/other-amps/6803-5150-choke-adjustabe-bias-mod.html#post48092




valvehead said:


> In my experiences---A power transformer will not affect an amp as far as tone or tightness. UNLESS--you have a weak or malfunctioning power trans that is not delivering proper current/ voltage.



Perhaps, but the transformers in the JCM2000 line of amps are weak and tends to overheat and sag when the amp is pushed. That does not contribute to good performance at band or gig level volumes. 



valvehead said:


> OT-----Ive installed many of them in many amps, The WAY overpriced Mercury , etc....I did not hear any difference--nor did the amp owners. Yes they are a better quality OT. Tone ? no. Go with a Heyboer.



I for one can state that the Lydian OT for the DSL will give you more clean output power, better low end and overall, better definition.



valvehead said:


> Im just not that familiar with the DSL--especially when the dam schematic takes off to " CON3" , CON14 , etc....  Just wondering where lead 1 stuff can be adjusted----- just asking in case a couple of you have done exactly what im talking about ---you dig ?
> 
> or maybe i shall dig into the schem.



For lead one, theres enough info on the 1st page that should help you out to start.


----------



## TwinACStacks

JC speaks the truth, valvehead.


 TWIN


----------



## jensbrix

Just did that resonance mod thingy to my DSL, added a 0.0047uF cap in series with the NFB resistor - I will recommend EVERY owner of the DSL to do this, it's one of the best mods I've done to it, and I've done alot by now. Thinking of releasing all the mods soon, I'm extremely satisfied with this beast!


----------



## cylon185

Free bump for the DSL


----------



## maltone

Help please with Joey Mods...

One thing that isn't clear to me in the Joey mods, are the WHY'S of doing these mods.
Examples: 

1) *Front Board Mod* Why? What does it do to the sound?

1M Resistor from Wiper to Ground on VR3 ****
C12 Lower to 150pf or REMOVE (I removed it)
C10 replace with .0022 uf
R20 Remove and JUMPER

2) *Mainboard Mods*: Again, how does it affect the sound? Why is this done?

C9 replace with 1000pf (.001uf) 500V
C12 replace with 1uf 63V

3) Frontboard Mod
_Also if You find that the Green CRUNCH Mode is too boomy especially with the deep switch engaged_
C8 replace with .001uf to .0022uf (I used .0015uf)
What effect will this have on the DEEP function? Will it tighten it up etc?

I just need some reference for these mods - the Joey Mods don't explain_ why _these are being done. Much thanks.






C8 replace with .001uf to .0022uf (I used .0015uf)


----------



## jcmjmp

maltone said:


> Help please with Joey Mods...
> 
> One thing that isn't clear to me in the Joey mods, are the WHY'S of doing these mods.
> Examples:
> 
> 1) *Front Board Mod* Why? What does it do to the sound?
> 
> 1M Resistor from Wiper to Ground on VR3 ****
> C12 Lower to 150pf or REMOVE (I removed it)
> C10 replace with .0022 uf
> R20 Remove and JUMPER



This affects the lead channel. The C12 cap give you more girth when using the gain control @ less than 6.
R20 makes Lead2 mode more useable by reducing gains slightly and shelving some of the bass out.
The 1M resistor to ground also make the Lead 2 channel a little clearer overall.
C10 is also to help with the low end and making it clearer with all that extra distortion in the Lead mode.



maltone said:


> 2) *Mainboard Mods*: Again, how does it affect the sound? Why is this done?
> 
> C9 replace with 1000pf (.001uf) 500V
> C12 replace with 1uf 63V


C9 on V1a plate to grid helps in reducing high end frequencies. This is a good thing since the freqs it filters out aren't really audible anyways.
C12 is the cathode cap on v1a and this will make the amp a little tighter by shelving out some low end up front to help with clearer distortion down the line (Soldanos and the Jubilee use a 0.68uf cap here.) You can add the bass later.




maltone said:


> 3) Frontboard Mod
> _Also if You find that the Green CRUNCH Mode is too boomy especially with the deep switch engaged_
> C8 replace with .001uf to .0022uf (I used .0015uf)
> What effect will this have on the DEEP function? Will it tighten it up etc?



C8 is in the crunch signal path. It is independant from the deep function.


----------



## maltone

Much thanks for the clarification JCM - that certainly helps. Today I've been trying to source the caps and resistors for the Joey Mods. In my readings today, I found something interesting - maybe you can chime in and give me your opinion... I found this article with regards to noise issues in resistors, caps in amps:
Resistor Types--Does It Matter?

*Contact Noise*

_Contact noise is dependent on both average DC current and resistor material/size. The most significant contributor to noise in guitar amplifiers is the use of low-wattage carbon composition resistors. Since the noise is proportional to resistor size, the use of 2W carbon comp resistors will improve the performance over that of 1/2W resistors. Studies have shown a factor of 3 difference between a 1/2W and a 2W carbon comp resistor operating at the same conditions.

The predominant noise in carbon comp, carbon film, metal oxide, and metal film is composed of contact noise, which can be very large at low frequencies because it has a 1/f frequency characteristic. Wirewound resistors do not have this noise, only resistors made of carbon particles or films. This noise is directly proportional to both the current flowing in the resistance and a constant that depends upon the material the resistor is made of.

If no current (AC or DC) flows in the resistor, the noise is equal to the thermal noise. The contact noise increases as the current is increased. This means that for low noise operation, the DC and AC currents should be kept low.

The material and geometry of the resistor can greatly affect the contact noise. Therefore, if you double the power rating of the resistor, which increases the size and area, you will reduce the contact noise generated by the resistor._ 

I wonder if you'd notice an audible difference?


----------



## gazzamarad

Hi. A mate of mine has a jvm 50watt head. His lead channel was a bit fizzy so we swapped out v1 with a 12at7 and what a difference. It allowed him to wind up the gain alot more to bring out a fatter tone. Has anyone tried this with the OD channal on the dsl with any positive result? I have done the treble bleed mod with the 150pf swap and that definitely helps...........


----------



## RickyLee

gazzamarad said:


> Hi. A mate of mine has a jvm 50watt head. His lead channel was a bit fizzy so we swapped out v1 with a 12at7 and what a difference. It allowed him to wind up the gain alot more to bring out a fatter tone. Has anyone tried this with the OD channal on the dsl with any positive result? I have done the treble bleed mod with the 150pf swap and that definitely helps...........




I have got SOMEWHAT similar results with putting a 5751 in either V1, V2 or both.

I was running a 5751 in V2 for awhile, but in the end I came back to all 12AX7's.

As for using 12AT7's in place of 12AX7 in GAIN stage circuits, there's just some different capacitive effects on the circuit that I am hearing. And then there's the high current draw ect. that they exhibit. That is basically why I tried to stay with a 5751 as it basically has the same characteristics of a 12AX7 but with aprox. 25% - 30% less gain.

Stay away from putting a 12AT7 in V3 which has the cathode follower circuit.


----------



## rockgod212

here are some of the mods i did to my dsl100. 

*remove all of the input diod circuit stuff and just use the classic input cicuit
c12-1uf
r15-3k (L1) 
c13-.47uf (L2)
c16-22n
r17-2.7k
r23-470p over plate
r34-10k/ .47 or .1 switched
r29-100p over 470k
r37-470k/470k= 235k into 500k pot
*remove r39- r40 and replace with 500k pot
*change grid resistors back to 5.6k
*change nfb to 100k/4ohm tap....cuts bass and adds top end back.....its on a switch to go back to 47k 
*all voltage dropping resistors from filter caps are 10k

*for those who are experienced enough.....do the bias mod (my schematic should get you there, but you need to know this amp to do it correctly, but if you do it, you wont regret it......it works and sounds great, and its alot easier to bias, just set it and forget it......study the amp schematic carefully as some of the components wont line up in their board positions, you will have to do some thinking...... 
*c36, c42, r77, r67, r69 will all go in their normal place on the board
*you will have to mount the board on short standoffs to make room under the board for the pot to mount to the chassis and r68 and the ground wiring, but its easy enough to do......also you get more air under the board for cooling.......
*marstran op tranny
*MM choke
*50uf mains
*40uf-screens
*33uf PI
*10uf-18uf preamp 

the amp sounds like a killer hot rodded marshall now.........

happy modding.......


----------



## RickyLee

rockgod212 said:


> here are some of the mods i did to my dsl100.
> 
> *remove all of the input diod circuit stuff and just use the classic input cicuit
> c12-1uf
> r15-3k (L1)
> c13-.47uf (L2)
> c16-22n
> r17-2.7k
> r23-470p over plate
> r34-10k/ .47 or .1 switched
> r29-100p over 470k
> r37-470k/470k= 235k into 500k pot
> *remove r39- r40 and replace with 500k pot
> *change grid resistors back to 5.6k
> *change nfb to 100k/4ohm tap....cuts bass and adds top end back.....its on a switch to go back to 47k
> *all voltage dropping resistors from filter caps are 10k
> 
> *for those who are experienced enough.....do the bias mod (my schematic should get you there, but you need to know this amp to do it correctly, but if you do it, you wont regret it......it works and sounds great, and its alot easier to bias, just set it and forget it......study the amp schematic carefully as some of the components wont line up in their board positions, you will have to do some thinking......
> *c36, c42, r77, r67, r69 will all go in their normal place on the board
> *you will have to mount the board on short standoffs to make room under the board for the pot to mount to the chassis and r68 and the ground wiring, but its easy enough to do......also you get more air under the board for cooling.......
> *marstran op tranny
> *MM choke
> *50uf mains
> *40uf-screens
> *33uf PI
> *10uf-18uf preamp
> 
> the amp sounds like a killer hot rodded marshall now.........
> 
> happy modding.......



For your bias mod, you did away with the dual pot and went with the standard one pot setup?

I added an additional trim pot in my bias circuit to give me more range/higher negative voltage value to run hotter valves like KT66 and KT88. But the KT88's are usally still too hot as the stock Dagnall power transformer does not put out enough voltage from the bias tap winding to begin with. One of the BIG bummers for me regarding the DSL and TSL amps. 

I am hoping that the new ClassicTone upgrade power transformer for these amps will address this issue. They are working on this new power transformer at I write.


----------



## jcmjmp

RickyLee said:


> I am hoping that the new ClassicTone upgrade power transformer for these amps will address this issue. They are working on this new power transformer at I write.



You could just get a Lydian PT - a drop in for the JCM2000 DSL. 

Marshall DSL Transformers

The bias is taken from the 22-0-22 vac taps. Your PT should be giving you these voltages in stock form. If not, your PT is our of spec.


----------



## cylon185

Definitely go for the Lydian stuff!
OT and PT.

Will make clips as soon as the DSL is fully serviced.


----------



## rockgod212

yeah only 1 pot, i wired it like a 2203 would have, works great with the
el34s. but i can see your problem with other tubes, you mite have to change all those bias resistors for the particular tube you want to use.........so this power tranny uses a low voltage tap, thats good to know......


----------



## RickyLee

jcmjmp said:


> You could just get a Lydian PT - a drop in for the JCM2000 DSL.
> 
> Marshall DSL Transformers
> 
> The bias is taken from the 22-0-22 vac taps. Your PT should be giving you these voltages in stock form. If not, your PT is our of spec.



The 22-0-22 is a bit lower than what I would like to ideally have. It really only applies if you try to run KT66's & KT88's. But I do have one set of Valve Art KT66's and one set of JJ KT88's that ran cooler than all my other KT66 KT88 valves and were just barely able to bias up safely in my TSL100. But all the other KT66's and KT88's I tried were way off the charts on the hot side.


----------



## jcmjmp

RickyLee said:


> The 22-0-22 is a bit lower than what I would like to ideally have. It really only applies if you try to run KT66's & KT88's. But I do have one set of Valve Art KT66's and one set of JJ KT88's that ran cooler than all my other KT66 KT88 valves and were just barely able to bias up safely in my TSL100. But all the other KT66's and KT88's I tried were way off the charts on the hot side.



I can have one made with a little more output if you want.


----------



## RickyLee

jcmjmp said:


> I can have one made with a little more output if you want.




Now that is what I have been waiting for right there!

LOL


Yeah, I will let you know. I have a bad situation with our Nissan Titan truck that is in the shop at the moment, so my $$ are tight. But that sounds like a winner for me. Maybe I will go with your OT as well when that time comes. Those will go in my TSL100 while my DSL100 already has the ClassicTone OT and I have the newly just being designed PT for the DSL100 coming when ClassicTone gets them finished. 

That bias tap just needs a few more volts to be honest. If you could put out 30-0-30, all the bases would be covered after rectification.


----------



## jcmjmp

RickyLee said:


> That bias tap just needs a few more volts to be honest. If you could put out 30-0-30, all the bases would be covered after rectification.



I can do that no problem. I even have a PT for the Japanese market (their line voltage is neiter 120 nor 240 vac).


----------



## maltone

JCMJMP, Ricky, this has probably been covered somewhere in here, but, I'd like to know for sure...

A friend came over yesterday, played his strat through the DSL and a MESA with V30's. His bridge pickup is a Jeff Beck Model, Seymor Duncan Humbucker, LOTS of balls. My TV Jones has less output, and he also thinks this amp is BRIGHT - to the point of being uncomfortable on the ears, ear splitting actually. It's like the lows aren't big or tight enough, the midrange is pretty good, but the treble frequencies are just too much and often obnoxious. 

Does the Joey mods cover that overly bright issue, where that brightness comes from. I really need to tame it, my ears are still ringing from yesterday. WOW


----------



## jcmjmp

maltone said:


> JCMJMP, Ricky, this has probably been covered somewhere in here, but, I'd like to know for sure...
> 
> A friend came over yesterday, played his strat through the DSL and a MESA with V30's. His bridge pickup is a Jeff Beck Model, Seymor Duncan Humbucker, LOTS of balls. My TV Jones has less output, and he also thinks this amp is BRIGHT - to the point of being uncomfortable on the ears, ear splitting actually. It's like the lows aren't big or tight enough, the midrange is pretty good, but the treble frequencies are just too much and often obnoxious.
> 
> Does the Joey mods cover that overly bright issue, where that brightness comes from. I really need to tame it, my ears are still ringing from yesterday. WOW



Marshalls are bright amps and the DSL is actually pretty tame in terms of Marshalls. You're comparaing your DSL to a Mesa, which is overly compressed and darker sounding. 
For the brightness, you could just change the coupling caps to a higher value, or turn the presence pot down.


----------



## maltone

JCM - comparing my DSL to a MESA? I meant the cab is a MESA cab, with 2 V 30's - not the MESA amp. 

It's intense. My friend has owned many high end Fenders, the Vibrolux, the Vibroking, JCM 800's, and he thought it was extremely bright, as do I. I can't imagine a non tame Marshall that's bright than this amp - that would be agonizing. 

Changing the Presence pot... If I turn down the presence to 3, or 4, you lose that articulation, but that CHANG or BLING sound is still underneath the tone. 

As for the coupling caps, it wouldn't dull the sound, but lessen that sharp SHING, BLING high end?

I'd probably want a change to both green and red, even the red is BLINGY, and sounds fizzy to me. It needs to be firmer and clearer.

_Marshalls are bright amps and the DSL is actually pretty tame in terms of Marshalls. You're comparaing your DSL to a Mesa, which is overly compressed and darker sounding. For the brightness, you could just change the coupling caps to a higher value, or turn the presence pot down. _


----------



## jcmjmp

maltone said:


> As for the coupling caps, it wouldn't dull the sound, but lessen that sharp SHING, BLING high end?
> 
> I'd probably want a change to both green and red, even the red is BLINGY, and sounds fizzy to me. It needs to be firmer and clearer.



Try an 10 band eq (or more) in the loop and see which frequencies you like boosted/cut out and take it from there.

Changing the coupling caps or even the plate->grid cap in V1a can help. They can really help in reducing the high end harmonics.


----------



## RickyLee

Yeah, the Joey Mods will help out that along with quite a few other areas as well.

Something you can try for the brightness would be to reduce the bright cap values in both channels.

I removed the bright cap on the Red channel and reduced the bright value on the Crunch mode to about half the value if I remember right (would have to find my notes).

Where are you setting the Gain controls for each channel?

I increased my phase inverter to power valve coupling caps from .022uF to .047uF for a bit more bottom end in the power section.


----------



## maltone

Thanks guys.. Ricky, that sounds like what I'm looking for. I find I'm rolling the presence down so low, and even lowering the mids from middle position to about 4 to roll off some of that bling, but it's still there.

My settings are almost always, 
GREEEN channel, CRUNCH ON
Volume at 4-4.5, 5 sometimes 6
Gain at 3-4 sometimes a bit higher.
DEEP switch ALWAYS ON. Damn I love that feature.

RED channel,
Volume about 4-5
Gain 1-2 MAX. 

I honestly don't find the red channel that useable. It's way too fizzy, and it has that CHUG CHUG gain sound if I even turn the gain up a hair. It's really sensitive.

I also find the red channel isn't firm enough, and it's fizzy - I just don't like it's voicing, but sometimes when I play around with the volume and set the gain REALLY low, like 1.5, it's _almost_ useable. It's never as firm and clear, robust sounding as the green channel though.

However - a next door neighbor loaned me his BOSS OD3. It's very cool, because I can set the amp on the green channel, CLEAN, no crunch, Volume at about 4-5, Gain at 3-4

I'll turn the LEVEL on the OD3 all the way up, and often the DRIVE is at 0, maybe 1-2, if that, TONE in the middle. It's like I can _almost_ get the same sound on the crunch channel settings, and not quite so loud, but adds even more girth + the DEEP switch on. Yes, there's some loss there with the bigness of sound, but then if I turn the presence up, turn the mids up etc, it still sounds pretty damn good and articulated. 

LAST, would changing the value of the capacitor on my tone pot make any difference? Currently there's a metal film .022mf in there. Could that be attributing to the brightness? Or would it just be better to change it at the source?



> I removed the bright cap on the Red channel and reduced the bright value on the Crunch mode to about half the value if I remember right (would have to find my notes).
> 
> Where are you setting the Gain controls for each channel?
> 
> I increased my phase inverter to power valve coupling caps from .022uF to .047uF for a bit more bottom end in the power section.


----------



## RickyLee

Running those gain controls set low is part of your problem with the harsh highs. The Green Channel has a 100pF bright cap across the Gain control that is there for both Clean and Crunch modes. Then there's another bright cap C6 1000pF that gets added to C4/switched in for a total of 1100pF when Crunch mode is on. You can try lowering the value of C6 to 470pF or even a bit lower. If you use a Silver Mica and leave the legs a bit long, you can start out with a real low value like 100pF and clip on additional caps in parallel to experiment to your liking.

As for the Red channel, it has a bright cap C12 470pF that is across it's Gain pot for both Lead 1 & Lead 2 modes. You can take some small cutters and snip one leg of that cap and bend it back. If one leg is a bit longer, cut that one in case you want to solder it back together from the top - this is the easy mod as you do not have to remove the board. And it is the best beginning mod for this amp. I did that and left my DSL100 stock for quite some time and was happy with it. A lot of other people just do that one mod as well and it is good enough for them. That alone should make you Red channel real close to the Green alone in the EQ'ing.

All these caps are all on the front PCB with the controls on it. I can say that my Lead 1 channel is the highlight of my DSL100 now. Just amazing what a few tweaks can do to this amp.


----------



## rockgod212

does anybody know how i can remove the reverb and fx loop completely out of the circuit, as i dont ever use them and i want a pure tube path.....


----------



## jcmjmp

RickyLee said:


> Running those gain controls set low is part of your problem with the harsh highs. The Green Channel has a 100pF bright cap across the Gain control that is there for both Clean and Crunch modes. Then there's another bright cap C6 1000pF that gets added to C4/switched in for a total of 1100pF when Crunch mode is on. You can try lowering the value of C6 to 470pF or even a bit lower. If you use a Silver Mica and leave the legs a bit long, you can start out with a real low value like 100pF and clip on additional caps in parallel to experiment to your liking.



Ricky - You hit the nail on the head. Maltone came over to my place to pickup his amp after I re-biased it and fixed the rear bias pot board (among other things). 

When I heard and saw the settings he was using (he played his Gretsch through the amp - beautiful guitar), I understood what kind of mods he needed. There's some real simple things to do on V1a and the treble bleed is another key element. These are all things I mentioned I could do to Maltone's amp already. In terms of low end tightness, the coupling caps are one aspect of that but without a good OT, I think that adding slightly less filtering between stages is a waste of time. Ricky - have you upgraded your OT yet? I don't remember.

To make a car analogy, there's no point in dumping money on the intake if you're gona keep the same exhaust system.


----------



## jcmjmp

rockgod212 said:


> does anybody know how i can remove the reverb and fx loop completely out of the circuit, as i dont ever use them and i want a pure tube path.....



The reverb can be switched out completely with the reverb footswitch. All you need to do is plug in a jack with the tip/ring connected together.

The FX is out of circuit if nothing is plugged into to it (bypassed with relays, like the reverb)


----------



## maltone

JCMJMP, that sounds good to me. I'm definitely going to change the OT, PT and add a choke - just can't afford it right now.

I think I might have my friend do the V1a cathode cap change, and then the treble caps as well. I want to order all the parts first - that I'll also need later on. I just can't stand this shrill BLING thing happening on the treble strings - it's SO annoying, and I always wake up the next day with my ears ringing. If you'd like to do the balance of the mods for me in the new year, what coupling caps could I order, and what values? Please let me know, and I'll assemble all the parts for you first. 

— JCMJMP I'm on your Lydian site right now, trying to find the correct PDF's for my 2008 DSL. One of the pics you sent to me when you were re-biasing my amp shows *JCM2-61-00* - I'm assuming this is the Front Board?

As for the Tube and Rear Boards...

Tube Board jcm2-60-00-*iss1*_TubeBoard100w.pdf 
Tube Board jcm2-60-02-*iss5*_TubeBoard100w.pdf
Tube Board jcm2-60-02-*iss7*_TubeBoard100w.pdf 

How do I determine what 100w Tube Board issue to look at? Is mine an issue 7? 

And what Rear Board?
jcm2-62-00-*iss1*_RearBoard.pdf
jcm2-62-02-*iss2*_RearBoard.pdf?

Thanks.


----------



## rockgod212

im really happy with the sound of my amp with my spec/mods i did to my dsl100. but a few things im not happy with and still need to change or figure out is: 
1. with the added gain pot it changed the intensity of the reverb, so i need to change the input and output impedence of the reverb, does anybody have any idea of what to change r41 and r44 to in order to get the reverb to sound right again? when the reveb is off is it completely out of the circuit, thinking about removing the reverb from the circuit, as i dont really use it. 

2. i love the way the amp sounds without the deep switch engaged, the amp sounds very much like a soldano now, but its way too much added lowend when deep is engaged, any ideas on modding the deep circuit to just give a little lowend thump. im thinking about rippin that circuit out and rewiring the presence to the normal circuit and adding a resonance control instead. any ideas on this......

3. when nothing is plugged into the fx loop is it completly bypassed or is the signal still going through all of the loop circuitry? dont use it-dont need it, how can i remove it completly, so i can have a pure tube, no loop marshall tone, like my plexi-2203.........


----------



## Joey Voltage

rockgod212 said:


> 2. i love the way the amp sounds without the deep switch engaged, the amp sounds very much like a soldano now, but its way too much added lowend when deep is engaged, any ideas on modding the deep circuit to just give a little lowend thump. im thinking about rippin that circuit out and rewiring the presence to the normal circuit and adding a resonance control instead. any ideas on this......



The presence IS the normal circuit. 5KL is a more useable value for the presence control, as it gives a more useable sweep, instead of 25K which isolates the presence cap too much and does nothing until the last quarter of it's sweep. 

to just give a little thump to the resonance you would have to damp the Q of the circuit by inserting resistance between the pole of sw5b and the junction of c29 and r43, or insert resistance between the connected throw of sw5b, and r30



rockgod212 said:


> 3. when nothing is plugged into the fx loop is it completly bypassed or is the signal still going through all of the loop circuitry? dont use it-dont need it, how can i remove it completly, so i can have a pure tube, no loop marshall tone, like my plexi-2203.........


it's still active, once aupon a time it looks like the plan was to have it footswitchable to be completely bypassed, but that would result in a pretty big volume jump.


----------



## rockgod212

Joey Voltage said:


> The presence IS the normal circuit. 5KL is a more useable value for the presence control, as it gives a more useable sweep, instead of 25K which isolates the presence cap too much and does nothing until the last quarter of it's sweep.
> 
> to just give a little thump to the resonance you would have to damp the Q of the circuit by inserting resistance between the pole of sw5b and the junction of c29 and r43, or insert resistance between the connected throw of sw5b, and r30
> 
> 
> it's still active, once aupon a time it looks like the plan was to have it footswitchable to be completely bypassed, but that would result in a pretty big volume jump.



1.on the presence, i meant the way the cap is wired to the pot, but thats really not an issue......
2.on the deep switch- so for less of a lowend thump, i would have to cut the trace to add the resistance....... 
3.fx loop- how can i bypass it completely? i cant follow the schematic for that one....
4.where is the signal tapped for the reverb and fx loop?


----------



## Joey Voltage

rockgod212 said:


> 1.on the presence, i meant the way the cap is wired to the pot, but thats really not an issue......


that doesn't make any difference.



rockgod212 said:


> 2.on the deep switch- so for less of a lowend thump, i would have to cut the trace to add the resistance.......


No, you just need to reconfigure the opamp to do the same thing. i.e ditch the boostrapping



rockgod212 said:


> 3.fx loop- how can i bypass it completely? i cant follow the schematic for that one....
> 4.where is the signal tapped for the reverb and fx loop?



The reverb is tapped from the preamp right before V3. The loop is post Tone stack. to remove the Loop, just remove RL3, and put a jumper between the throw and pole that connects to R40. also to save your self some additional loading remove R40 pot board.

to adjust the reverb on the tube board r41 is the Mixer, if you need a weaker mix increase it, and that might just be enough. other wise you will have to play with the send level, and it will take some juggling to find the optimum between between the required drive, while keeping the loading reasonable. 

If you want to ditch it, just unplug the tank, or even easier dont use it, you are not doing your self any favors by cutting anything out in that area if you already have your sound. And this wont prohibit you from using it's pots for other things so long as you appropriately disconnect them.


----------



## rockgod212

joey thanx for your help on this.....

1. what is bootstrapping, im not familar with that term?
2. gotcha on the reverb, i can fix that now......

3. so to remove the loop, remove RL3b- and jump between junction of 
RL2b/r40 to junction of RL3b/r25......is this correct? should i also remove r25?

4. looks like r40 is where the signal is tapped for the loop, in theory all i would have to do is remove r40 to remove the loop, correct?


----------



## Joey Voltage

Correct, but keep r25, It is functioning as a pull down to keep all the relay contacts at the same DC bias in order to avoid pops. 

R40 is where the loop sends, however it looks like RY3 is normally de-energized defaulting to the loop in state, that's why I recommended to get rid of it and permanently jump it. It says mute, but it doesn't appear to be providing that function from the scheme, it looks like at one point it was intended to be for a loop bypass.


----------



## rockgod212

got it, that makes sense now, i might just put the loop on a dpdt switch, so if i ever need it, it still works.....
what would it take to make the loop foot switchable......thanx for your help....


Joey Voltage said:


> Correct, but keep r25, It is functioning as a pull down to keep all the relay contacts at the same DC bias in order to avoid pops.
> 
> R40 is where the loop sends, however it looks like RY3 is normally de-energized defaulting to the loop in state, that's why I recommended to get rid of it and permanently jump it. It says mute, but it doesn't appear to be providing that function from the scheme, it looks like at one point it was intended to be for a loop bypass.


----------



## RickyLee

jcmjmp said:


> Ricky - You hit the nail on the head. Maltone came over to my place to pickup his amp after I re-biased it and fixed the rear bias pot board (among other things).
> 
> When I heard and saw the settings he was using (he played his Gretsch through the amp - beautiful guitar), I understood what kind of mods he needed. There's some real simple things to do on V1a and the treble bleed is another key element. These are all things I mentioned I could do to Maltone's amp already. In terms of low end tightness, the coupling caps are one aspect of that but without a good OT, I think that adding slightly less filtering between stages is a waste of time. Ricky - have you upgraded your OT yet? I don't remember.
> 
> To make a car analogy, there's no point in dumping money on the intake if you're gona keep the same exhaust system.



My DSL100 has the ClassicTone output transformer 40-18055. I also have the Mercury Magnetics 3 Henry choke MAR100C. But I still have the stock power transformer for the time being.

Regarding Maltones brightness issue, I gave him some pointers on experimenting with those bright caps C6 & C12 just to get him by for awhile. And the way that he is running his amp, that alone will help him out in a huge way. He is not running that amp like the rest of us do with the Gains set well above 5, 6 or 7.


----------



## cylon185

hey guys,
sorry to jump in but, could anyone help me to find a replacement part for RL3 ?
Can't seem to understand the full specs...


----------



## maltone

Thanks Ricky. I find this amp sounds best (to me) with the crunch channel on, volume at half (MAX) and gain around 3-4.

It's definitely got bite, but if you pick more softly, it get semi-clean. You dig in harder, and then it growls. I love the tone, it's just too fizzy, and way to bright. So I'll take yours and JCM's advice to tame that bling/shing I'm hearing. 

It's as if the voicing is in reverse; the low end isn't defined or rich enough, the mids (although I love that midrange bump - (GOWNK sound) seems fizzy at times, not focussed or rich enough, and brights are way over the top.
I just want it to sound....balanced.



RickyLee said:


> My DSL100 has the ClassicTone output transformer 40-18055. I also have the Mercury Magnetics 3 Henry choke MAR100C. But I still have the stock power transformer for the time being.
> 
> Regarding Maltones brightness issue, I gave him some pointers on experimenting with those bright caps C6 & C12 just to get him by for awhile. And the way that he is running his amp, that alone will help him out in a huge way. He is not running that amp like the rest of us do with the Gains set well above 5, 6 or 7.


----------



## guitargoalie

hey everyone, I know nothing when it comes to working with electronics soldering and modding, so I would have to bring my DSL to a tech if I get any of these mods. Can someone briefly explain how these mods affect the tone? Will it be apparent at low volumes or will I have to turn it up to notice? If anything I'm trying to make my dsl less fizzy and thin, and more jubilee-esque. thanks


----------



## RickyLee

guitargoalie said:


> hey everyone, I know nothing when it comes to working with electronics soldering and modding, so I would have to bring my DSL to a tech if I get any of these mods. Can someone briefly explain how these mods affect the tone? Will it be apparent at low volumes or will I have to turn it up to notice? If anything I'm trying to make my dsl less fizzy and thin, and more jubilee-esque. thanks



I would say the mods listed here will get it closer in tone to the Jubilee's Razor Sharp crunch. I can say this because yesterday I was running my DSL100 together with my 2555 Jubilee Clone in stereo. I have performed a few of the basic mods listed in this thread on my DSL100. And I also tweaked a few other areas as well. I would advise you to do the full mods as they were listed to get the best performance.

But you can get by with just a few basic mods to improve these amps slightly. Removing reducing the value of the front PCB C12 bright cap for the Red channel is a good start. And lowering the value of the bright cap C6 on the same PCB for the Green channel to about half - 470pF will help. And then lower the value of the first gain stage cathode bypass cap on the tube/valve main PCB C12 from 4uF to 1uF or even a bit lower, like .68uF. These mods alone will improve the amp and you might be happy with the tone for the time being.

What city/country do you live in?


----------



## gazzamarad

Hi all. Joey mods I have done
Pot board
1m resistor wiper to ground vr3
c12 to 150pf
c10 replace .0022
R20 remove and jumper

tube board
R30 piggyback to value 190

MM o/t and 3h choke.

To date i have found advantages and disadvantages. 
To explain and maybe point the finger I will mention a guy on a Tsl forum who suggested that the MM o/t is better and more linear at loud volumes but the stock 3070 dagnall had some tonal qualities at lower volumes that are warmer and truer to the marshall sound.( The MM never runs hot whereas the stock dag does.) I tend to agree here as I still find my mods in the lead channel are a definite improvement but overall I feel the amp has lost some of its spunky marshall definition. I have read this forum quite thoroughly and while there are one or two mods I could still do I am thinking that I may have upgraded with the wrong o/t for the sound that " I am chasing"....which is a vintage marshall sound. (should I have gone for the c1998 dagnall?)I recently A/B my head with a 50watt 
1973 marshall head...( yes lucky me tho not mine) linked both inputs on the 73... great sound tho dsl obviously more versatile. End result was that my dsl sounded less alive, deader than the old 73. The 73 had more bite and sting in the mid range.
My settings on the dsl are
eq...pres 6 treb 5 mid 5 bass 8....deep switch on
ultra gain 2; vol 4 gain 2 (cant get above this due to feedback. I do use a tubescreamer drive 9 oclock, tone 5, level 3oclock)
clean vol 4 gain 7 with tube screamer as I prefer this to crunch mode, which I dont use, so far)...As well as reading the pages above I am really starting to wonder if the o/t is the key here. Dont get me wrong the MM is a mo fo of a tranny but maybe more for "big gigs" rather than small pub venues. Can some of you wonderful lads help me out a bit here....I may just need to do c9 and c12 mods to finish up, I dont know. My amp tech is a great and patient human but I'm sure I am starting to wear him thin just like my wallett! LOL...My head is a 2006 100watt with the improved pcb board with the 5k6 values. It still has the c46 on it. Should that be removed?
Thanks to everyone on this remarkable forum for all of your input...cheers ...Gaz


----------



## gazzamarad

P.s. c9 and c12 on the tube board I meant to say.
Also I have 4 shuagang EL34m output tubes.
Preamp tubes are v1 mullard, v2 NOS sylvania, v3 tung sol, v4 NOS sylvania..all 12ax7
I have found this ax7 array to be the best combo so far...cheers


----------



## gazzamarad

Correction......Shuguang EL34B's I mean........By the way even without the TS on I still find it difficult to get the gain in the lead channel (ultra) above 2 with vol 4 to 5 without uncontrollable feedback. I have an sg with a bill lawrence HB (11.5k) on the bridge. Lead 1 is more useable as far as increasing gain goes but to date I have found I prefer the overall texture of lead 2. So how do you guys get to use your gain up around 5,6 and7 as per ricky lee's post above? Is it single pole pups?


----------



## gazzamarad

Hi guys...guess everyone is on holidays or somethin. Well I seem to have sorted out my sound further. I recently bought a fulltone fulldrive off ebay. Custom shop cream 2004 model. Wow this definitely opens up the amp! Significantly better than my old reliable Ibanez TS808. (which seemed to choke the sound somewhat). I have also been able to now disengage the deep switch which was vital with the TS. My only question now is regarding the lead channel. How do I get more use of the gain as I cannot turn mine above 2 before feedback? Volume set 4 to 5? I have done the joey mods. My C12 cap replacement (silver mica) measures around 110pf on my amp tech's meter. Sounds about right. Just feel it needs a little more bottom oomph esp now I dont use the deep switch. Ideas anyone...regards...Gaz


----------



## Jason77

If you want more bottom oomph, you can add a .0047uf cap between the 100k negative feedback resistor and the 4ohm tap on the rear board.

As for your feedback issue, I'm wondering if your pickups are microphonic. What guitar are you using and what pickups are in it?


----------



## Jason77

Correction: I meant to say 47k negative feedback resistor.


----------



## gazzamarad

Hi Jason. I play a Tokai Sg with bill lawrence humbucker in the bridge position. Its a little hotter than a PAF. About 10.2k I think. I have the same issue with my two LPJ double cutaways. They have different pups again, so I dont think they all could be microphonic. A good thought though mate. Can you elaborate further on the negative feedback resistor thing please? And does this only affect the lead channel? Thank you...Gaz


----------



## Jason77

Gaz..

I was thinking your pickups may not be potted and causing the feedback but I guess thats not the case. Now I'm just stumped.

As for adding the cap to the NFB resistor, it basically adds clean low end to your signal, making the low end clearer and punchier. It works similarly to how the presence control adds more highs. To me, it has a more natural feel than the deep switch. I like .0047uf but if you want more lows, you could use a .0033uf or even a .0022uf.

The NFB resistor is R19 on the rear board. You just need to disconnect the leg that connects to the 4ohm spade connector and solder the cap in between.


----------



## Jason77

Gaz..

I was thinking your pickups may not be potted and causing the feedback but I guess thats not the case. Now I'm just stumped.

As for adding the cap to the NFB resistor, it basically adds clean low end to your signal, making the low end clearer and punchier. It works similarly to how the presence control adds more highs. To me, it has a more natural feel than the deep switch. I like .0047uf but if you want more lows, you could use a .0033uf or even a .0022uf.

The NFB resistor is R19 on the rear board. You just need to disconnect the leg that connects to the 4ohm spade connector and solder the cap in between.


----------



## Landshark

The more I play my amp after doing some of these mods, I notice the mids are gone on my crunch channel (TSL mind you). Any way to fix this?

Mods are...

front board:

C12 removed
R20 jumped
C10 .0022 uf
C8 .001 uf

main board:

C12 1uf 63v ( replaced stock option)
C9 1000pf (.001uf)

Choke installed

It sounds great, except there are almost no mids on the crunch channel. Any ideas on how this happened?


----------



## RickyLee

Landshark said:


> The more I play my amp after doing some of these mods, I notice the mids are gone on my crunch channel (TSL mind you). Any way to fix this?
> 
> Mods are...
> 
> front board:
> 
> C12 removed
> R20 jumped
> C10 .0022 uf
> C8 .001 uf
> 
> main board:
> 
> C12 1uf 63v ( replaced stock option)
> C9 1000pf (.001uf)
> 
> Choke installed
> 
> It sounds great, except there are almost no mids on the crunch channel. Any ideas on how this happened?



Interesting. I am getting ready to start messing with my TSL100 in the next week or so. I was thinking I would like to start out by altering the Lead channel first so I could compare it with the Crunch channel.


----------



## RickyLee

Landshark said:


> The more I play my amp after doing some of these mods, I notice the mids are gone on my crunch channel (TSL mind you). Any way to fix this?
> 
> Mods are...
> 
> front board:
> 
> C12 removed
> R20 jumped
> C10 .0022 uf
> C8 .001 uf
> 
> main board:
> 
> C12 1uf 63v ( replaced stock option)
> C9 1000pf (.001uf)
> 
> Choke installed
> 
> It sounds great, except there are almost no mids on the crunch channel. Any ideas on how this happened?



Which schematic relates to the components and the board you are calling "front board"? The components you are talking about sound similar to the DSL which I am familiar with. I am not familiar with the TSL though. Does the TSL have a similar layout to the DSL for the TSL Crunch & Lead?


----------



## RickyLee

Has anyone tried replacing the TSL Crunch channel's stock Gain pot that is supposedly 220K, with a 1 MEG pot?


----------



## gazzamarad

Thanks alot Jason. I will definitely consider the NFB R19 mod with .0047 cap. With the feedback issue it only occurs on the lead channel but i am managing to control it enough at gigs so I will perservere. I really appreciate your input...thanks again


----------



## Landshark

RickyLee said:


> Which schematic relates to the components and the board you are calling "front board"? The components you are talking about sound similar to the DSL which I am familiar with. I am not familiar with the TSL though. Does the TSL have a similar layout to the DSL for the TSL Crunch & Lead?



I was told by Joey at one point that you use the lead channel board in the TSL instead of the front board from the DSL.


----------



## RickyLee

Landshark said:


> I was told by Joey at one point that you use the lead channel board in the TSL instead of the front board from the DSL.



Which TSL schematic did you go off of? I can't find the R20 on the TSL schematic - but there's an R20 on the DSL schematic.

Or are you saying that there is a TSL circuit board that is identical to the DSL board and the component numbers are matched up as well?


----------



## Landshark

RickyLee said:


> Which TSL schematic did you go off of? I can't find the R20 on the TSL schematic - but there's an R20 on the DSL schematic.
> 
> Or are you saying that there is a TSL circuit board that is identical to the DSL board and the component numbers are matched up as well?



When I said front board, I meant the lead channel pcb in the TSL. and yes I was under the assumption that the component changes from the DSL would be identicle to the TSL. R 20 was on the lead channel pcb.


----------



## RickyLee

Landshark said:


> When I said front board, I meant the lead channel pcb in the TSL. and yes I was under the assumption that the component changes from the DSL would be identicle to the TSL. R 20 was on the lead channel pcb.



Wow, that is quite cool. I will get to working on my TSL possibly this weekend.


----------



## RickyLee

Landshark said:


> The more I play my amp after doing some of these mods, I notice the mids are gone on my crunch channel (TSL mind you). Any way to fix this?
> 
> Mods are...
> 
> front board:
> 
> C12 removed
> R20 jumped
> C10 .0022 uf
> C8 .001 uf
> 
> main board:
> 
> C12 1uf 63v ( replaced stock option)
> C9 1000pf (.001uf)
> 
> Choke installed
> 
> It sounds great, except there are almost no mids on the crunch channel. Any ideas on how this happened?



Bummer, as I just found R20 on this Lead channel schematic, but it looks to be part of the switching or FX or Reverb or something along those lines - and C8 C10 C12 are not near that R20. I am looking over the schematic "OVERDRIVE CHANNEL FRONT CONTROL PCB".

C12 on my Lead channel board (OVERDRIVE) is part of the tone shift circuit in the tone stack - SW1C. C section/pole of switch 1.

So I am going to see how my Crunch channel looks, as that must be what your components relate to possibly?

EDIT: On the "CRUNCH CHANNEL schematic, C8 & C9 are part of the Crunch channel's Tone Shift circuit. C10 is part of the tonestack and C12 is a 10n cap going to Ground from the "Clean Reverb" pot.


----------



## RickyLee

Landshark said:


> The more I play my amp after doing some of these mods, I notice the mids are gone on my crunch channel (TSL mind you). Any way to fix this?
> 
> Mods are...
> 
> front board:
> 
> C12 removed
> R20 jumped
> C10 .0022 uf
> C8 .001 uf
> 
> main board:
> 
> C12 1uf 63v ( replaced stock option)
> C9 1000pf (.001uf)
> 
> Choke installed
> 
> It sounds great, except there are almost no mids on the crunch channel. Any ideas on how this happened?






RickyLee said:


> Bummer, as I just found R20 on this Lead channel schematic, but it looks to be part of the switching or FX or Reverb or something along those lines - and C8 C10 C12 are not near that R20. I am looking over the schematic "OVERDRIVE CHANNEL FRONT CONTROL PCB".
> 
> C12 on my Lead channel board (OVERDRIVE) is part of the tone shift circuit in the tone stack - SW1C. C section/pole of switch 1.
> 
> So I am going to see how my Crunch channel looks, as that must be what your components relate to possibly?
> 
> EDIT: On the "CRUNCH CHANNEL schematic, C8 & C9 are part of the Crunch channel's Tone Shift circuit. C10 is part of the tonestack and C12 is a 10n cap going to Ground from the "Clean Reverb" pot.



So after looking over this TSL100 schematic a bit - and getting a headache in the process - I am figuring I will just base my modification strategy along the lines of tinkering with the TSL Lead channel first and doing some of the similar DSL Joey Mods and also going in the direction of a JCM 800 2203/4 preamp topology.

@Landshark: I was trying to figure out what you had done and the values/components you listed, but it is not transposing to my TSL amp or the schematics. So I am figuring I need to look at your info there as DSL parameters/topology and transpose that to the TSL to have it make sense.

Whew! 

But, man this TSL schematic not having CON to Con/PCB to PCB references is a HUGE BUMMER.

I think I need to start another TSL Mods thread. I started one quite some time ago, but it had no interest from anyone here. And I can't find the thread as well - I searched for it but can't find it.


----------



## Landshark

Actually Ricky, what you said in reference to the overdrive pcb makes perfect sense. The tone shift being involved in some of those components I changed and or removed would explain the loss of mids. It's like the tone shift is engaged constantly, which it a terrible sound for this amp. Then I've also been having issues with the reverb not working coreectly, which could be a result of R20 being changed. Looks like I could solve some issues by taking the overdrive pcb in my TSL back to stock form.


----------



## RickyLee

Landshark said:


> Actually Ricky, what you said in reference to the overdrive pcb makes perfect sense. The tone shift being involved in some of those components I changed and or removed would explain the loss of mids. It's like the tone shift is engaged constantly, which it a terrible sound for this amp. Then I've also been having issues with the reverb not working coreectly, which could be a result of R20 being changed. Looks like I could solve some issues by taking the overdrive pcb in my TSL back to stock form.




Yeah, I was hoping you would look into my post on those component differences, and see if that had something to do with your issues.


----------



## Landshark

I have to order the part for C12 cause I broke the leg off when I removed it. After it arives I'll let you know if everything is restored.


----------



## Doug_MN

New DSL 50 owner here. So, I've read all 27 pages twice and I have a few questions regarding the "Joey_Voltage" mods. 

1) Are there any audio clips of this mod? Any A/B comparisons?

2) Please explain what "darkens" means with respect to the tone?

3) Does the "JoeyV" mods sound anything like the "JCM2000 FJA mods" on YouTube?

4) After posting the original "Joey_Voltage" mods on page 1, many users discussed further changes to address specific tones or noise problems. Are the page 1 original mods still valid?

5) Most of my amp's usage is basement level playing. Will an OT and choke upgrade be noticeable?

6) Does the "JoeyV" mods turn the DSL into more of a metal oriented amp? If most of my sounds I wish to recreate are classic rock (AC/DC, Zep, Rush, ZZ Top...) will these mods deliver?

Any advice is most appreciated!

Doug


----------



## Jason77

Doug,

I hear ya... after 27 pages, your head starts to spin and it can get a bit confusing. I read this tread over and over before i modded my dsl 50. I can't answer all your questions but I'll try to clear some of it up as best I can...

The mods on page one are the crux of the mods. In the pages beyond that, many people used that as a starting point, then started tweaking to taste to better suit their needs. I got overwhelmed by that and tried many of the other mods listed in the thread but found that it was more than what I was looking for because I was combining mods that didn't need to go together, if that makes sense.

What the joey mods (as listed on page 1) do, is remove muddiness from the low end so its a little more tighter and defined (as opposed to boomy), and add a little more clarity and emphasis to the mids, upper mids. It doesn't turn it into a high gain monster. If anything, it gives it more of an metal panel/800ish feel, perfect for classic rock though it can still get into higher gain territory if you wish.

I recently got a DSL 100 and held back on the amount of mods I did. I didn't change the value of R30 as I didn't feel the amp was very dark. I didn't add the 1M resistor on vr3 and used a value of .0022uf on c8.

I think if you start off with what's listed in the first post, you'll be fine. I'd do R30 and 1M on vr3 later, if you feel you need it. If at that point, you feel its close but not quite there, I'd post a specific question about what you're trying to get out of it.

Hope that helps.


----------



## Landshark

I'm back to normal Ricky! Thanks for the insight man!


----------



## RickyLee

Landshark said:


> I'm back to normal Ricky! Thanks for the insight man!



Good to hear.

I was able to get quite a few components swapped in my TSL100 earlier today. This injury I have had since the middle of last December has been kicking my ass LOL. It was good to be able to actually sit up at a table and do something for a change.

Something that has always baffled me on this amp as well as my DSL100, is the B+ power supply rail. Namely that 1K R62. What is the purpose of that small value? Much less, why even have a low value dropping resistor like that? What am I missing here?

 

I increased that one on my DSL100 so I could have much lower tolerable voltages at V3 cathode follower. I had about 450V running on pin1 of V3 in my DSL100. So I lowered those voltages last year and got them down closer to 330V and also got the voltages at the cathode much lower. That was a hard slot on valves in that amp. New production valves have a tough time with those high voltages.

So I changed that resistor 1K R62 to 10K 2W as well as the 4.7K R63 to 10K 2W in my TSL100. Did some other component swapping that I will fill you in on later when the amp is completed - and of course, have to see how it sounds.


----------



## guitargoalie

I have a question for the mods on the first page. I'm really liking my dsl crunch green, but its a bit loose and low gain. I have a model on my pod floorboard based on the chandler tube driver, when i kick it in with the gain around half and level at full, it just barely tightens it up and adds a small amount of dirt, will the joey mods tighten up the green and add a touch of gain? I'd rather get all my tone from the amp lol


----------



## jensbrix

Changing to the 1uf cathode on first gain stage will help tighten it alot, its a must to do it in my oppinion. More gain can be done in several ways, depending on what you want


----------



## shane159

I have read that you lose a little gain on the lead 1 of the DSL when you remove the C12 cap. Does the lead 2 still work and if so how is lead 2 affected?


----------



## TheLoudness!!

Can anyone tell me about the Fortin mods?

I am looking for an insane modern metal tone with tight low end and awesome punch.


----------



## TheLoudness!!

nobody?


----------



## RickyLee

TheLoudness!! said:


> Can anyone tell me about the Fortin mods?
> 
> I am looking for an insane modern metal tone with tight low end and awesome punch.



I would like to hear about this as well.


----------



## jensbrix

Are you talking about the mods from the Fortin forum, or are you talking about something completely different?


----------



## rockgod212

not to take anything away from anybody working on these amps or what they have come up with, but im sorry guys if you really want to fix these amps the right way then check out my spec some pages back.....yes its a major overhaul or rebuild, but its so worth it in the end.......

with my spec. my green and red 1 channels sound the same tonally....anyway heres something that has always baffeled me about these amps.....
the green channel is so loud and full, but when i switch to red 1 (i do use a 1n brite cap on red channel, i prefer it with my spec) theres a volume drop, or compressed sound....both channels are at the same volume, only the gains are are at diferent settings......the green is voiced the same as the red, but the red only adds 1 stage, so what gives?


----------



## rockgod212

heres an update on my spec......i rebuilt this amp from the ground up and it was a labor of love for me to do it.....lots of trial and error, and lots of hours and playing invloved to get it to this final spec......



rockgod212 said:


> here is what i changed to revoice my dsl100.
> 
> *remove all of the input diod circuit stuff and just use the classic 68k input cicuit
> 
> 1. 1.5k/1uf/220k plate
> 2. 3.3k lead 1/ lead 2 adds .47uf cap......1n brite cap on red 1 channel
> 3. 2.7k
> 4. 10k/ .1uf or .47uf on/off/on switched
> 5. 1k
> 
> c16-22n
> r23-470p over plate
> r29-470p over 470k
> r37-470k/470k= 235k into 1meg pot with 470k wiper to ground...
> *remove r39- r40 and replace with 1 meg pot pot
> *change r41 to 120k to adjust reveb mix
> *change grid resistors back to 5.6k
> *NFB is switched to 100k/ 50k@ 4ohm tap with fixed resonance mod .0047uf, more natural lowend and when deep is engaged feel the earth shake without mush or fizz.....
> *all voltage dropping resistors from filter caps are 10k, PI dropper are stock 4.7k
> *switchable trebel peaker circuit. 470k/470p or 470k/2n2, the cap can be bypassed also.
> 
> *for those who are experienced enough.....do the bias mod (my schematic should get you there, but you need to know this amp to do it correctly, but if you do it, you wont regret it......it works and sounds great, and its alot easier to bias, just set it and forget it......study the amp schematic carefully as some of the components wont line up in their board positions, you will have to do some thinking......
> *c36, c42, r77, r67, r69 will all go in their normal place on the board
> *you will have to mount the board on short standoffs to make room under the board for the pot to mount to the chassis and r68 and the ground wiring, but its easy enough to do......also you get more air under the board for cooling.......
> *marstran op tranny
> *MM choke
> *50uf mains
> *50uf-screens
> *33uf PI
> *10uf-18uf preamp
> 
> the green channel will now give you plexi drive up to full on jcm800 on major steroids (the green channel will clean up when guitar vol. is rolled back).... the red 1 takes you into soldano gain territory, and red 2 takes you to a mesa/compressed type sound, but still sounds marshall'y.
> the amp sounds absolutely killer now. this is how to build a high gain amp with out mush or fizz.....
> 
> happy modding.......


----------



## sfb

*remove all of the input diod circuit stuff and just use the classic 68k input cicuit
What is the diffirent with this mod and stock with diodes & beads.


----------



## rockgod212

i dont really know what its supposed to do, i just know theres a tone or sound difference without it......and i prefer it.....i mean that stuff was never on any other marshall....too many extra circuit stuff on this amp, that marshall claims is a safety feature....i call them tone robber circuits...


----------



## RickyLee

rockgod212 said:


> not to take anything away from anybody working on these amps or what they have come up with, but im sorry guys if you really want to fix these amps the right way then check out my spec some pages back.....yes its a major overhaul or rebuild, but its so worth it in the end.......
> 
> with my spec. my green and red 1 channels sound the same tonally....anyway heres something that has always baffeled me about these amps.....
> the green channel is so loud and full, but when i switch to red 1 (i do use a 1n brite cap on red channel, i prefer it with my spec) theres a volume drop, or compressed sound....both channels are at the same volume, only the gains are are at diferent settings......the green is voiced the same as the red, but the red only adds 1 stage, so what gives?



In regards to the extra compression on the Red channel vs. the Green channel, you have to consider that the Red goes through an extra gain stage. 

And then I am thinking there's a bit of inter-stage attenuation (I really should look back at the circuit/schematic before saying this one LOL) going on there to compensate the extra gain. The Green channel has a bit more AC audio signal swing or headroom somewhat. 

I was just playing my modified DSL100 cranked up pretty good here at my house this evening along with my Ceriatone 2555 after putting new quads of power valves in each amp (Wing C EL34 in the DSL - GT KT66HP in the 2555).

My DSL is just very intense and amazing now. I am thinking all the work I did to it is settling in - mostly the 3 Henry choke and the ClassiscTone output transformer upgrade. My Red Lead 1 is the highlight of the amp now hands down.


----------



## rockgod212

ditto ricky lee.....i love my red channel now.....that makes sence about the headroom bewteen the 2 channels, i didnt think about that....i love my amp as well....but i dont play through it enough these days...im always using my metro 2203....


----------



## RickyLee

I am still fine tuning my DSL100 Red channel Lead 1 & 2 modes - mostly by ear now. I ended up tinkering with three values of Sozo caps in place of the stock ceramic cap C16 4n7 MAIN PCB, which is the coupling cap coming directly after V1AA (second triode of V1 - I hate that labeling as I would rather call it V1B LOL) which is the second gain stage/extra stage that is only used on the Red channel. For this C16, it seems the .0022uF sounds the best between the other .0047uF & .0068uF. But . . . 

My mods are quite similar to all the Joey Mods here on the front board. I went in and added the 1MEG to ground on the wiper of VR3 and jumpered R20 just a couple days ago. My Red channel was already the highlight of this amp before I added these last two mods, but I was having just a bit too much bottom end Girth on lead 1 & 2. My 1936 cab with G12-65's was resonating and vibrating a bit too much from all the low end. And when I would palm silence my low E, the bottom end would woof out similar to a Triple Rec.

So now I am thinking I will do that last front PCB Joey Mod of lowering C10 from .0047uF to .0022uF. But that will knock down the voicing I have now with the change to C16 which is after/downstream of the front PCB shaping/voicing circuit. Which means I might go back and raise up the value of C16 by ear and see what sounds best, which will allow to to drive the next gain stage with a bit more gain and bottom end while hopefully retaining the awesome clarity I now have in my mids and upper mids on full chords.

Also, I tinkered with lowering the value of the one mixing/summing resistor R79 470K which is on the MAIN PCB. It gave the Red channel a bit more gain - but I was looking to raise the volume of the red channel to be closer to the output volume of the green channel. It worked somewhat as this lowering also knocked down the volume of the Green channel as well LOL. But I did not like what it did to the gain response of the Green channel, so I left it alone for now. My Crunch channel volume (I have the Clean Crunch footswitch mod with a separate Crunch volume) usually gets set a lot lower lower than the Red channel volume. Crunch at about 3 and Lead 1 at 5 to 6 on their volumes.

Anyone else here tinker with that MAIN PCB C16?


----------



## RickyLee

RickyLee said:


> I am still fine tuning my DSL100 Red channel Lead 1 & 2 modes - mostly by ear now. I ended up tinkering with three values of Sozo caps in place of the stock ceramic cap C16 4n7 MAIN PCB, which is the coupling cap coming directly after V1AA (second triode of V1 - I hate that labeling as I would rather call it V1B LOL) which is the second gain stage/extra stage that is only used on the Red channel. For this C16, it seems the .0022uF sounds the best between the other .0047uF & .0068uF. But . . .
> 
> My mods are quite similar to all the Joey Mods here on the front board. I went in and added the 1MEG to ground on the wiper of VR3 and jumpered R20 just a couple days ago. My Red channel was already the highlight of this amp before I added these last two mods, but I was having just a bit too much bottom end Girth on lead 1 & 2. My 1936 cab with G12-65's was resonating and vibrating a bit too much from all the low end. And when I would palm silence my low E, the bottom end would woof out similar to a Triple Rec.
> 
> So now I am thinking I will do that last front PCB Joey Mod of lowering C10 from .0047uF to .0022uF. But that will knock down the voicing I have now with the change to C16 which is after/downstream of the front PCB shaping/voicing circuit. Which means I might go back and raise up the value of C16 by ear and see what sounds best, which will allow to to drive the next gain stage with a bit more gain and bottom end while hopefully retaining the awesome clarity I now have in my mids and upper mids on full chords.
> 
> Also, I tinkered with lowering the value of the one mixing/summing resistor R79 470K which is on the MAIN PCB. It gave the Red channel a bit more gain - but I was looking to raise the volume of the red channel to be closer to the output volume of the green channel. It worked somewhat as this lowering also knocked down the volume of the Green channel as well LOL. But I did not like what it did to the gain response of the Green channel, so I left it alone for now. My Crunch channel volume (I have the Clean Crunch footswitch mod with a separate Crunch volume) usually gets set a lot lower lower than the Red channel volume. Crunch at about 3 and Lead 1 at 5 to 6 on their volumes.
> 
> Anyone else here tinker with that MAIN PCB C16?



LOL . . . It looks as if I should find my DSL modding notes from many months ago. As I flipped around the front control PCB, I found that I had jumpered C10 as part of all my initial mods last year.


----------



## rockgod212

i returned to mostly stock values on my amp, but i did lower c16 to 2n2........
on my 4th stage i still have 2.2k with .47/.1 on a 3way switch, thinking of changing the .47u to .68u.......

thinking of adding the 1meg on vr3 or adding the 1meg to r30, how do those 2mods sound? 

screens filters are stock, but im returning to stock mains filters, actually i have 100u/100u on the board and then i mounted a 3way standoff thing so i can add a 100u filter cap in parallell over the series caps, or adjust it from there, cause 165u is too much, but 50u total isnt enough........somewhere around 100uf total i imagine would be great for this amp, so well see.....im really looking to get more upper mids, like in the FJA clips.......i want it to scream......

havnt put the amp back together yet, so no sound test yet.....

ricky lee, i would leave the 2n2 on the main board and adjust from the pot board, remove c10, or i have switchable trebel peakers, and the 470k/470p does sound good with this amp.....so thats an option as well.....


----------



## RickyLee

rockgod212 said:


> i returned to mostly stock values on my amp, but i did lower c16 to 2n2........
> on my 4th stage i still have 2.2k with .47/.1 on a 3way switch, thinking of changing the .47u to .68u.......
> 
> thinking of adding the 1meg on vr3 or adding the 1meg to r30, how do those 2mods sound?
> 
> screens filters are stock, but im returning to stock mains filters, actually i have 100u/100u on the board and then i mounted a 3way standoff thing so i can add a 100u filter cap in parallell over the series caps, or adjust it from there, cause 165u is too much, but 50u total isnt enough........somewhere around 100uf total i imagine would be great for this amp, so well see.....im really looking to get more upper mids, like in the FJA clips.......i want it to scream......
> 
> havnt put the amp back together yet, so no sound test yet.....
> 
> ricky lee, i would leave the 2n2 on the main board and adjust from the pot board, remove c10, or i have switchable trebel peakers, and the 470k/470p does sound good with this amp.....so thats an option as well.....



Well I got a touch less woofy Recto bottom end, so I am going to leave it where it's at until I can play out with this amp. I have C10 jumpered and I already lowered C8 on the MAIN board way down to 4n7 anyway. So I see no need for me to have a cap in that C10 position. Or am I not understanding something in that signal path? Front board C10 stock is 4n7 but it is directly following/in series with the very first coupling cap C8 MAIN board which stock was .022uF. 

Adding that 1MEG to Ground did not give me a change I could hear. If you read up on Joey's explanation of the theory behind the change, it is effecting much lower frequencies which I figured would help with my low end heavy tone anyway. When I jumpered R20, I heard a very subtle gain increase. For the peaker, I like the higher value stock 2n2 across the 470K myself. I need the extra upper mids.

I was thinking about tinkering with the MAIN board R30 as well. I tried lowering it only in the past and did not like it - I like it with a bit more gain. I thought about trying a higher value for more beef as well.


----------



## rockgod212

im not sure on the trace, but on the main board C8 is the 1st stage coupler
(i would leave the stock 22n in there) and C8 on the pot board is for the green channel- so if you lower it to 2n2 the green would be less boomy without losing lows in the red.......C10 on the pot board affects the red lead's only- its really not needed, so i removed it- but if i find i need to cut bass out of the red i'll put it back in.........yeah you dont need that r20-47k that cuts the gain of the peaker.......




RickyLee said:


> Well I got a touch less woofy Recto bottom end, so I am going to leave it where it's at until I can play out with this amp. I have C10 jumpered and I already lowered C8 on the MAIN board way down to 4n7 anyway. So I see no need for me to have a cap in that C10 position. Or am I not understanding something in that signal path? Front board C10 stock is 4n7 but it is directly following/in series with the very first coupling cap C8 MAIN board which stock was .022uF.
> 
> Adding that 1MEG to Ground did not give me a change I could hear. If you read up on Joey's explanation of the theory behind the change, it is effecting much lower frequencies which I figured would help with my low end heavy tone anyway. When I jumpered R20, I heard a very subtle gain increase. For the peaker, I like the higher value stock 2n2 across the 470K myself. I need the extra upper mids.
> 
> I was thinking about tinkering with the MAIN board R30 as well. I tried lowering it only in the past and did not like it - I like it with a bit more gain. I thought about trying a higher value for more beef as well.


----------



## rockgod212

for anybody that knows.......

on the pot board........what value do you have for R38, on my schematic it says 10k, but i have a 470k in my amp- that just doesnt make sence, so what is the correct value and is that resistor really even needed? im thinking it should be 100k, as that is a pretty common resistor to add to 800's....


----------



## Jason77

RickyLee said:


> So I see no need for me to have a cap in that C10 position. Or am I not understanding something in that signal path?



Ricky, I think this may help. In this thread (which is where the Joey mods originated):

http://www.marshallforum.com/workbench/11566-dsl-info-2.html

Joey's response to c10 being redundant is:



Joey Voltage said:


> NO! It is absolutley NOT redundant and it needs to be there in that circuit or else the OD channel gain will be fizzier, and buzzier!!!
> 
> Passing more bass early in the chain causes this for many different reasons, and cutting the bass early actually makes it smoother because when bass frequencies distort, their harmonic content when mixed will sound buzzier especially when distortion involved, and you can potential encourage blocking this way, and nothing sounds worse than that! you will notice most of the best designers actually cut a lot of bass earlier, and then deal with putting it back later.


----------



## RickyLee

rockgod212 said:


> im not sure on the trace, but on the main board C8 is the 1st stage coupler
> (i would leave the stock 22n in there) and C8 on the pot board is for the green channel- so if you lower it to 2n2 the green would be less boomy without losing lows in the red.......C10 on the pot board affects the red lead's only- its really not needed, so i removed it- but if i find i need to cut bass out of the red i'll put it back in.........yeah you dont need that r20-47k that cuts the gain of the peaker.......



Yes. I lowered the first interstage coupler C8 on the MAIN PCB from .022uF down to .0047uF. This affects ALL channels/modes. AND, C10 on the front pot PCB is tied to this/in series going into the Red channel. So that is why I see no need to have that C10 on the pot board. Which reminds me that I should check and see what I did last year on the Green channel's C8 on the pot board? I might need to jumper that now. But before I lowered preceding MAIN PCB C8 from .022uF down to .0047uF, I demo'ed various values there first
because it does affect ALL channels/modes. Which brings me to Jason's input LOL. 





Jason77 said:


> Ricky, I think this may help. In this thread (which is where the Joey mods originated):
> 
> http://www.marshallforum.com/workbench/11566-dsl-info-2.html
> 
> Joey's response to c10 being redundant is:



Yes, I understand Joey's explanation. BUT, that is with the coupling cap that is upstream of C10 (C8 on the MAIN PCB) being the .022uF value and letting through more lower frequencies. I have this MAIN PCB C8 lowered down to .0047uF. So basically I am already cutting out this fizz ect. before it gets to the front control PCB. Really, it would be great to hear what Joey would have to say about what I did. I can see an argument for needing to take the jumper off of my front control PCB C10 and install a .0047uF - which being in series with that upstream/preceding MAIN PCB I lowered to .0047uF = .00235uF LOL.







rockgod212 said:


> for anybody that knows.......
> 
> on the pot board........what value do you have for R38, on my schematic it says 10k, but i have a 470k in my amp- that just doesnt make sence, so what is the correct value and is that resistor really even needed? im thinking it should be 100k, as that is a pretty common resistor to add to 800's....



You are referring to the resistor just before/upstream of the two Master Volumes? 

My schematic shows 470K and that is what's in my amp as well. What schematic are you looking at? Do you have an earlier revision of this amp?

FYI: I played around with lowering the value of that resistor. Added quite a bit more volume to an already loud and beastly amp.


----------



## rockgod212

do me a favor ricky......look on your pot board and tell me what value you have for R38....its the resistor before the master volumes.....my schem says 10k, but i have 470k in my amp.......


----------



## RickyLee

rockgod212 said:


> do me a favor ricky......look on your pot board and tell me what value you have for R38....its the resistor before the master volumes.....my schem says 10k, but i have 470k in my amp.......



LOL I put my amp back together already. I have to have my Gal help me lift my gear around as well as my Doctor has part of my restrictions as not lifting over 5 pounds (L5/S1 herniated disc) even though I am doing much better than that now. LOL that would mean I can't pour a glass of water from a gallon of Sparklett's drinking water.

I am quite certain mine is 470K (I did not double check the color code though) as it measured about half that value, but it was in the circuit with other components influencing its value/parallel.

I will probably get inside ithe DSL100 here soon. It is going to band rehearsal with me tomorrow along with my Ceriatone 2555 Jubilee that I currently have opened up AGAIN LOL. I was just AB'ing the Ceriatone 2555 against my '89 Marshall 2550 once again. Found some interesting results this time comparing them. And it made me take out a couple mods I had done to the Ceriatone as well (lowered B+ to the preamp & cathode bypass cap added to V2A).


----------



## rockgod212

thanx ricky, i looked up some other schem's of the amp and they all had 470k, though i do wonder why that resistor is even there......whats its purpose?


well after returning my amp to basicly stock, its dead......i get very little sound with the green master cranked.......tried several other pre-tubes, checked my work on the pot board 3 times- that was ok, time to check the main board.......


----------



## RickyLee

rockgod212 said:


> thanx ricky, i looked up some other schem's of the amp and they all had 470k, though i do wonder why that resistor is even there......whats its purpose?
> 
> 
> well after returning my amp to basicly stock, its dead......i get very little sound with the green master cranked.......tried several other pre-tubes, checked my work on the pot board 3 times- that was ok, time to check the main board.......



Yeah. These amps are a pain in the ass for soldering work. Double check the solder pads you worked, that your solder is not making contact with the adjacent solder pad of the component next to it. Bummer is, that if you find two adjacent pads that are making contact/continuity, you have to distinguish if it is supposed to make contact. Or did you accidentally make them have continuity.

Also check for lost solder pads. I lost a couple on this amp myself.

That 470K is in series in that circuit - which means it is knocking down a bit of voltage but the current remains the same. When I tried lowering it a bit, the amp got REALLY LOUD. And this amp is already a loud beast anyway. That could be the reason it is in there.


----------



## rockgod212

got it working, but i have some other issues to work out......red gain is unresponsive and i lost lead2, as i changed r21=150k to 470k i need to change it back.....also on the red it seems like its farting out on the low notes.....i should probably remove 4n7 fixed resonance.....i wont know more till i crank it up and see what needs to be tweaked......so far it sounds like the old dsl i used to know.....lots of gain with xtra 500k pot.......that fixed some issues.....still need red gain fixed.....


----------



## rockgod212

i tracked my issues down to a bad gain pot and some bad trace/ solder pads around red channel gain circuitry, so i hard wired in a pot and bam the amp was back in working order........and it sounds killer now........i returned the amp back to mostly stock, stock voltages and sorta stock filters, but i left a few of my mods alone........the added 500k pot right before the last stage really opens the amp up and makes it scream, but i had to change the R41 reverb mix resistor to 120k to lower the reverb effect......it just kills now, cant wait to get a mini pot for my red lead gain and put it back together......
it needs new pots anyway.....


----------



## Nedrick

Wow rockgod, what a journey you have been on......and to wind up at almost the beginning. May I ask what are your mods at this time? I've been pouring over the posts for the last couple days trying to decide what I should do. It was kind of a surprise to end up at yours. 

As a new member, let me first thank all of you for your contributions. A couple of questions about tightening. Many of these mods are to help with that. If you use all of them is it possible to get too tight? Also, it seems mostly related to the flabby bass. I can appreciate that, but to me everything could stand to be tightened. Maybe some of these are specific to mids and highs as well, but I could have missed that going through all these pages.

My amp has been gunny sack for over a month now. I was held up on trying to get the channel switching mods. Thank God I stumbled on here and was able to contact Graham directly to get that sorted out. I think I'll wait until that's done first before doing a whole lot of mods. Although I have a good general sense of what I want, this way it will be easy to A/B all the channels for a more accurate comparison. Plus, it's been a while since I've heard the damn thing. Interesting how we can have different ears listening to the same thing.


Thanks again to everyone for their input.

Regards 

Ned


----------



## RickyLee

rockgod212 said:


> i tracked my issues down to a bad gain pot and some bad trace/ solder pads around red channel gain circuitry, so i hard wired in a pot and bam the amp was back in working order........and it sounds killer now........i returned the amp back to mostly stock, stock voltages and sorta stock filters, but i left a few of my mods alone........the added 500k pot right before the last stage really opens the amp up and makes it scream, but i had to change the R41 reverb mix resistor to 120k to lower the reverb effect......it just kills now, cant wait to get a mini pot for my red lead gain and put it back together......
> it needs new pots anyway.....



Cool.

This pot you added before the last stage, did you put it in place of R40 as an adjustable grid load? And did you drill a hole for it in the chassis?


----------



## mickeydg5

rockgod212 said:


> do me a favor ricky......look on your pot board and tell me what value you have for R38....its the resistor before the master volumes.....my schem says 10k, but i have 470k in my amp.......


 


RickyLee said:


> You are referring to the resistor just before/upstream of the two Master Volumes?
> 
> My schematic shows 470K and that is what's in my amp as well. What schematic are you looking at? Do you have an earlier revision of this amp?
> 
> FYI: I played around with lowering the value of that resistor. Added quite a bit more volume to an already loud and beastly amp.


 
There is that 470k R38 again.

*Ricky*, I am sorry I did not notice that later issue of the schematics. I thought that I had browsed around on only saw the 10k value.

Here is the deal.
An amplifier with the 10k R38 will have 680k at R47 and R48, after PI . (earlier amps)
An amplifier with the 470k R38 will have a LINK at R4 and R5, resistor spots after PI in the same locations. (later amps)


----------



## rockgod212

no...well sorta......i removed r40 and removed r39, that is the voltage divider for the previous stage into the next stage.....wire a 500k gain pot as the new voltage divider....changed r41 to 120k to adjust reverb mix......

also on r34- 2.2k cathode i have a .47u/.1u on a on/off/on switch, this really sounds nice with the added pot, i can really crank that pot up for more gain without using lead 2 and it sounds really nice with lead2 as well......

i also dont use the loop, so i completely bypassed it.....



RickyLee said:


> Cool.
> 
> This pot you added before the last stage, did you put it in place of R40 as an adjustable grid load? And did you drill a hole for it in the chassis?


----------



## RickyLee

mickeydg5 said:


> There is that 470k R38 again.
> 
> *Ricky*, I am sorry I did not notice that later issue of the schematics. I thought that I had browsed around on only saw the 10k value.
> 
> Here is the deal.
> An amplifier with the 10k R38 will have 680k at R47 and R48, after PI . (earlier amps)
> An amplifier with the 470k R38 will have a LINK at R4 and R5, resistor spots after PI in the same locations. (later amps)


Interesting. I have not looked at the earlier schematic myself. But with this scheme you are mentioning, the earlier version amps are getting the phase inverter hit a bit harder than the later version amps?


----------



## mickeydg5

RickyLee said:


> Interesting. I have not looked at the earlier schematic myself. But with this scheme you are mentioning, the earlier version amps are getting the phase inverter hit a bit harder than the later version amps?


 
I would say that it does affect the PI some but the bigger concern for Marshall was lowering the signal for the loop.


----------



## rockgod212

hnce the reason i bypassed it........i dont like loops as they cut the tone....
but to each their own....


----------



## RickyLee

Or the loop could make the tone better. I would say it depends on what you stick in it, and how you stick it in there.


----------



## mickeydg5

RickyLee said:


> Or the loop could make the tone better. I would say it depends on what you stick in it, and how you stick it in there.


 
Most definitely! I like loops.


----------



## rockgod212

update i changed the xtra pot to 250k, as its closer to the stock voltage divider............now i can dime it and make the amp scream bloody murder.....i also added 47pf on VR4's wiper to ground- takes the fizz away, the amp sounds very much like some of the clips from FJA's mods.....a very very hot-rodded jcm800.........this thing just screams.......

question..........i have the red 1-2 sounding great......is there anything i can do to clean up the clean a bit more, as its still a little crunchy from the added pot.......also the green channel could be cleaned up a bit as well without changing my stages......i have them perfect for the red....maybe i can clean it up from the pot board somehow?




rockgod212 said:


> no...well sorta......i removed r40 and removed r39, that is the voltage divider for the previous stage into the next stage.....wire a 500k gain pot as the new voltage divider....changed r41 to 120k to adjust reverb mix......
> 
> also on r34- 2.2k cathode i have a .47u/.1u on a on/off/on switch, this really sounds nice with the added pot, i can really crank that pot up for more gain without using lead 2 and it sounds really nice with lead2 as well......
> 
> i also dont use the loop, so i completely bypassed it.....


----------



## D-Max

> An amplifier with the 10k R38 will have 680k at R47 and R48, after PI . (earlier amps)
> An amplifier with the 470k R38 will have a LINK at R4 and R5, resistor spots after PI in the same locations. (later amps)



The 680K at R47 and R48 are only there in a TSL; The DSL won't have them as they are part of the TSL's V.P.R. function.
The older schematic with R47 and R48 having a 680K is a actually a TSL schematic.


----------



## mickeydg5

D-Max said:


> The 680K at R47 and R48 are only there in a TSL; The DSL won't have them as they are part of the TSL's V.P.R. function.
> The older schematic with R47 and R48 having a 680K is a actually a TSL schematic.


 
I have seen (some of) the TSL schematics as well.

Nope, you have to look at early DSL's and their schematics.
Some amplifiers had 10k (R38) and the links while others had the 10k (R38) and the 680k (R47, R48) respectively.

Later DSL amplifiers had the 470k (R38) with the links.
There are probably other differences too.


----------



## D-Max

OK, I wasn't entirely clear...
The older 100W schematic (here), Tube Board issue 1, is actually a schematic for the TSL122 combo, TSL100 head and DSL100 head.

I've only seen only once a DSL issue 1 tubeboard. From what I recollect (and I hope my memory serves me correctly) is that there were no 680K resistors, just the links.
If both the DSL and TSL had the 680K, then the DSL full out would have been less, much less louder then the TSL full out (with the TSL having the same amount of volume with the V.P.R. engaged).
The 680K resistors in a DSL would have acted as fixed post PI master volume, which the V.P.R. is.

The earlier linked schematic is for the 100W JCM2000 chassis.
It shows 680K for R47 and R48 and the CON9 4-pin connector for the V.P.R./Mute and the Line Out circuits

The notes in the upper right corner state the differences between the 3 models:
*Note #5:
R47,R48 = LINK STANDARD
R47,R48 = 680K COMBO & DELUXE

Note #6
CON9 ONLY FITTED ON COMBO & DELUXE*

Where...
Standard=DSL100 head
Combo=TSL122 combo
Deluxe=TSL100 head


----------



## mickeydg5

Yes, those are the schematics I was refering. But I am not following your logic or explanation on which would be louder.

An early DSL with a 10k R38 and 680k R47/48 should be just as loud as a TSL with a 10k R38 and 680k R47/48.

Ricky only mentioned that the later model DSL with the 470k R38 and LINKed R47/48 was louder when the value of the 470k R38 was decreased.

I see the CON9. I do not see where it connects to anything. I have heard of the VPR. Where is it?

Nowhere does it say the the Deluxe = a TSL100. I take Deluxe as being special DSL design amplifiers. A TSL is a TSL.

Needless to say I do not trust everything read or seen on Marshall schematics. They have always had too many versions of any amplifier design floating around. And their quality control on deck is not exemplary. The only way to be sure of what is in your Marshall box is to open it up and trace the circuits.


----------



## rockgod212

thanx for clearing some of this up......

so whats a VPR.......?

i have the 4 and 5 links, so why is that 470k resistor even used, what is its purpose?........i mean it was never in a 800 or 2203 amp, is it just to tame the volume of the amp, as does marshall think no one plays loud anymore? 
ive heard of this sort of thing being done before, but with a 500k volume pot and 470k coming from treble pot into vol. pot. 
is this the same effect as putting a 100k from wiper of volume pot to cap of P.I., as i have that on my metro 2203 clone?
is there any tonal benefit having that 470k there?


----------



## D-Max

V.P.R. is the Virtual Power Reduction feature on the TSL.

It is a switchable fixed post PI master volume; it switches between 100% and 25% signal to the power tubes (according to the manual).
Here is where R47 and R48 being 680K along with CON9 come in to play.




CON20 connects to CON9.
Switch S3a/S3b engages the V.P.R.
In the same circuit is also the Output Mute function, which is switched by S4a and S4b (when VPR is engaged, one can switch between the 25W mode or complete mute). The output mute shunts both halves of the input of the power amp together. R59, R61 and R55/R58/R62/R70 are now all tied together on one side, meaning no push-pull operation is possible (any signal applied will be in phase for both sides of the power amp.

Going through the TSL schematics will make this clear.

On the the question if the DSL had the 680K resistors: no, they didn't, never.
But if there is any evidence (like pics of the board) I am glad to revise that statement 
If so, then the 680K tandem together with the 220K tandem (R59/R61) would be a voltage divider, reducing the applied signal to the power tubes to approx. 25%.
In case of the TSL's normal mode, the VPR is switched off.
Hence - if the DSL had 680Ks - the DSL then being much quieter then a TSL.
The DSL never had a VPR function.

The R38 10K vs. 470K is not related to the R47/R48 topic, not at all.
R38 was initially 10K, later on Marshall increased it to 220K and in the end to 470K.
As mentioned earlier in a post, it was done to avoid the FX loop (which is solid state and powered with a +/-15V) would clip.

For the issue 1 tube board schematic: the combo, standard and deluxe designations are as I stated before.


----------



## rockgod212

ok...i understand that a bit more now......dsl's dont have vpr's then.
i dont use loops, so i bypassd it.....
so i could lower r38 to my preference then? right now i jumped a 220k over the 470k and it sounds good, lots more volume and clarity- maybe a bit too much added volume, ill have to wait to crank it up....i might settle on jumping 470k over r38....that should put me in the range of volume im looking for.....
thanx for the help...


----------



## mickeydg5

*D-max*, I see what you are saying and have to trust. I know the VPR is on the TSL. I meant that it is not in the DSL or its schematics as if it were never implemented, CON9 goes nowhere, as far as I can see. Has anyone ever seen a VPR on a DSL or even a DSL Combo or a DSL Deluxe. I have not seen these DSL boards so have no verification of what Marshall actually did in those amplifiers. I do take it that the TSL came out a year or two so later after the DSL launch of the JCM2000 line. I associate the JCM schematics with the DSL and the TL schematics with the TSL for those amplifiers in the JCM2000 line.


----------



## mickeydg5

rockgod212 said:


> ok...i understand that a bit more now......dsl's dont have vpr's then.
> i dont use loops, so i bypassd it.....
> so i could lower r38 to my preference then? right now i jumped a 220k over the 470k and it sounds good, lots more volume and clarity- maybe a bit too much added volume, ill have to wait to crank it up....i might settle on jumping 470k over r38....that should put me in the range of volume im looking for.....
> thanx for the help...


 
This was kind of covered. You can lower R38 value somewhat but want to watch as to not over power and distort the loop.


----------



## D-Max

Marshall most likely designed the different 100W JCM2000s in one go and working with internal product names for the different models in that stage, completing engineering on the DSL and taking the DSL into production first.

It also makes sense that the TSLs were released later then the DSLs, especially from a marketing perspective to offer an "upgrade" path to an even more flexible amp in the same product range.
The revision dates on this schematic seem to validate that http://www.drtube.com/schematics/marshall/tl10-61-02.pdf
A buddy of mine bought a brand new TSL in late 1998 as graduation gift for himself... or maybe early 1999.

In the second half of the '90s I spent a lot of time on Ampage and TSLs were discussed then already (1998?). Overthere and then I first heared about the link between standard/deluxe/combo v.s. DSL head/TSL head/TSL combo.

Enough on the TSL and hijacking a DSL thread


----------



## rockgod212

as i said, i removed RL3 and hard wire bypassed the loop, so no worries about distorting the loop with lowering R38...... 





mickeydg5 said:


> This was kind of covered. You can lower R38 value somewhat but want to watch as to not over power and distort the loop.


----------



## mickeydg5

rockgod212 said:


> as i said, i removed RL3 and hard wire bypassed the loop, so no worries about distorting the loop with lowering R38......


 
Oh, sorry. If the loop is bypassed then by all means lower it to taste. I would crank it to make sure the drop is not too much like mentioned. The power section is setup for a certain output. The resistor at R38 should not be lower than the amp or you can stand. Well if it can make that much difference anyway.

I really like loops though.


----------



## rockgod212

thinking about removing r38 and using a 500k pot as a variable resistor, or jumping a 250k pot over the 470k.....a fine tune volume control......


mickeydg5 said:


> Oh, sorry. If the loop is bypassed then by all means lower it to taste. I would crank it to make sure the drop is not too much like mentioned. The power section is setup for a certain output. The resistor at R38 should not be lower than the amp or you can stand. Well if it can make that much difference anyway.
> 
> I really like loops though.


----------



## mickeydg5

rockgod212 said:


> thinking about removing r38 and using a 500k pot as a variable resistor, or jumping a 250k pot over the 470k.....a fine tune volume control......


 
Can you get to maxium volume with no problems?
If the 220k fairs out and there are no problems, then yes. 
I would go with a 2M pot for maximum range of adjustment. Be conservative on the adjustment and make it based on maximum volume.


----------



## rockgod212

i think im settling on jumping a 470k over r38 to make r38=235k.......
it gave the amp a bit more volume with some added punch and it really gave the amp a little more topend, which i was hoping for. 
it really made the amp scream a bit more due to earlier feedback occuring.

it also really opened up the green channel- now it really does sound like a hot rodded 800 on some steroids.
the red just takes it even further into saturation.
all in all it really opened up the amp, gave the amp its balls back so to speak.
im really happy with it. 

if any of your guys dsl's have the 4-5 links on the main board, i would be curious as to what value r38 is on your amps, and if you have the 470k there, try jumping another 470k over it and tell me what you think of it.......


----------



## RickyLee

Yes to all the VPR info posted. Good stuff guys.

There was also a good post by Jon Wilder explaining the VPR in detail quite some time ago. I wish I could find that Wilder post myself.

As for that R38 470K on the main PCB, I tinkered with that myself quite some time ago. I found that lowering the value made my already too loud DSL even louder and harder to get into that "sweet spot" at a decent lower volume. And it made the amp become unstable. I think that is the reason it is there and you do not see that topology in a 2203/4 as it there for some attenuation from all the extra gain/audio signal these amps put out. 

I was thinking about putting a pot there to act as an overall master volume. But I do not really feel like drilling any holes in my chassis at this time.


----------



## Jason77

Well this is interesting. My schem says 220k for r38. I'll have to take a look inside the amp tomorrow and see what's actually there.


----------



## rockgod212

look on the mainbord for links 4 and 5, they should be by the phase inverter circuitry........see if you have them and let me know what R38 is......



Jason77 said:


> Well this is interesting. My schem says 220k for r38. I'll have to take a look inside the amp tomorrow and see what's actually there.


----------



## Jason77

I'm looking inside the amp now and this is what I've got:

r38 = 470k

r4 and r5 = links


----------



## rockgod212

cool thanx for the info......

i ended up leaving r38=470k stock, but i added a on/off/on switch to add another 470k or 1m over it.....adds a bit more volume, slightly different tonal texture to it...i like it.....


----------



## rockgod212

here something i understand.......on the potboard.....
why did marshall use a 220n from the mid pot to ground?
i just jumped it with a wire and oh my god did it open up the tone stack, it gave the amp its growl back......try it and let me know what you think of it...


----------



## Jason77

Wow, I never really noticed that. I'll definitely try jumping it and see what it sounds like.


----------



## rockgod212

its c24 on the pot board......i couldnt believe it.......all the classic marshall mids came back......its those mids that make the marshall growl famous....


----------



## Jason77

For the hell of it, I looked at the TSL schematic (since they're related) to compare, but that cap doesn't exist in the TSL. Odd.


----------



## mickeydg5

RickyLee said:


> As for that R38 470K on the main PCB, I tinkered with that myself quite some time ago. I found that lowering the value made my already too loud DSL even louder and harder to get into that "sweet spot" at a decent lower volume. And it made the amp become unstable. I think that is the reason it is there...
> 
> I was thinking about putting a pot there to act as an overall master volume. But I do not really feel like drilling any holes in my chassis at this time.


 
That is what I was waiting to hear. It is overkill and Marshall most likely settled at 470k being the best for all worlds (settings) for the loop and downstream stages.


----------



## mickeydg5

rockgod212 said:


> here something i understand.......on the potboard.....
> why did marshall use a 220n from the mid pot to ground?
> i just jumped it with a wire and oh my god did it open up the tone stack, it gave the amp its growl back......try it and let me know what you think of it...


 
I was wondering if someone was going to pick up on this component.
The thing is can you get the same tone by tweaking controls?
And, did you loose any bottom end control by bypassing the 220nF (C24)?


----------



## RickyLee

mickeydg5 said:


> I was wondering if someone was going to pick up on this component.
> The thing is can you get the same tone by tweaking controls?
> And, did you loose any bottom end control by bypassing the 220nF (C24)?



Yeah, that C24 is breaking the usual tonestack to Ground/Negative connection and bleeding/passing frequencies to Ground.

I put a 100K midrange pot in my DSL which gave me all the mids I would ever want LOL. But I would rather have a 50K pot which they do not make in those Korg style pots. 

My DSL has too much bottom end with that 100K mid pot. Well, actually I should say I lost some of the Bass pot ability to turn the Bass down. That is more of a correct observation.

I guess I could try putting my stock mid pot back in and put a small 20K trim pot in place of that C24.

EDIT: Or you could put a switch in place of C24 for a Boost function of lifting the tonestack Ground. BUT that might not work in this circuit as there's already quite a bit of AC signal gain going through this circuit.


----------



## mickeydg5

Yes, too large of a midrange pot will affect the bass control.

The 220nF C4 is there to aid in preserving bass frequency and control. It is a low pass filter component and sets the cutoff for low frequency attenuation.


----------



## Jason77

(nevermind this post. just saw Mickey's post, which answered my question)


----------



## rockgod212

my amp is anything but stock, so i prefer c24 bypassed- i didnt lose any lowend or nothing like that....in fact it improved the tonal response for my amp......so for me it works.....the only part of my amp that is solid state is the deep switch which sounds better now that i put a 4n7 in line with
the 47k nfb.....


----------



## mickeydg5

I told Ricky this earlier. I think it applies here too as well as lots of other places.

The thing with a lot of design and tinkering is that there is give and take. As long as you are happy with the results and it all works well together, what more can you ask for?
Do not answer that.


----------



## rockgod212




----------



## Jason77

OK, I jumped c24 and i do like it better that way. Its subtle, but it does have a little more bark.

While i was in there on the pot board, I also changed r12 to 100k to get a little more out of the crunch mode and changed r2 to 33k to bring back some mids to the clean.


----------



## rockgod212

i thought those who tried it would like it.........i feel it makes the tone controls much more responsive and interactive......

next up is to replace all the pots with regular mini pots using fly leads.....ill leave the reverb pots to hold the board up, but when i did the red gain pot the old one measured 800k, so out of spec they are.....they get stuck, so time to replace them with correct value pots.... 




Jason77 said:


> OK, I jumped c24 and i do like it better that way. Its subtle, but it does have a little more bark.
> 
> While i was in there on the pot board, I also changed r12 to 100k to get a little more out of the crunch mode and changed r2 to 33k to bring back some mids to the clean.


----------



## RickyLee

I have my DSL opened up again. It was not sounding like I thought it should last time I played it. Probably due to me playing through that Bandmaster I have been tinkering on.



I just took some measurements, and I am getting continuity to the metal chassis on both ends of that C24.



I replaced a couple of preamp valves and it is sounding a bit better now. I was hearing some extreme spikey treble coming through on all channels, which is odd. This thing has been more bottom end heavy than all my other amps.

I am thinking about either putting the stock mid pot back in as I have a 100K in there now. Or I am going to see if I can put a resistor on one leg of this 100K mid pot to make it react like a 50K pot.

Figuring I will try a 50K resistor from the wiper to Ground. As the way I am seeing this tonestack, whatever value mid pot is used, keeps that value between the tonestack and Ground at all times regardless of the mid pot setting. Where a Fender type tonestack is set up to put the tonestack entire mid pot value to Ground when its mid pot is at 0.

If I am incorrect here, someone let me know please.


----------



## RickyLee

RickyLee said:


> I have my DSL opened up again. It was not sounding like I thought it should last time I played it. Probably due to me playing through that Bandmaster I have been tinkering on.
> 
> 
> 
> I just took some measurements, and I am getting continuity to the metal chassis on both ends of that C24.
> 
> 
> 
> I replaced a couple of preamp valves and it is sounding a bit better now. I was hearing some extreme spikey treble coming through on all channels, which is odd. This thing has been more bottom end heavy than all my other amps.
> 
> I am thinking about either putting the stock mid pot back in as I have a 100K in there now. Or I am going to see if I can put a resistor on one leg of this 100K mid pot to make it react like a 50K pot.
> 
> Figuring I will try a 50K resistor from the wiper to Ground. As the way I am seeing this tonestack, whatever value mid pot is used, keeps that value between the tonestack and Ground at all times regardless of the mid pot setting. Where a Fender type tonestack is set up to put the tonestack entire mid pot value to Ground when its mid pot is at 0.
> 
> If I am incorrect here, someone let me know please.



Strange. Jumpering C24 makes no change in my amp, so I was reading it correctly - seeing Ground continuity on both ends of that cap. I guess I should lift my PCB to see if it was jumpered already.

And the tinkering with a resistor to lower my mid pot value from 100K only allows me to get an absolute zero Bass setting. Having the mid pot at 100K just makes the lower range of the Bass control inoperative.


----------



## mickeydg5

Ricky, maybe your C24 is jumped or shorted.

If you want that 100k pot to act more like a 50k place a 100k across the the outside tabs, not to the wiper. That should give about 50k. A 68k will yield about 40k total. And so on.


----------



## RickyLee

I tinkered with lowering that 100K and there's no need to do it. The 100K gives the option of Mucho Mids LOL. And the change to the Bass control is that you can't turn the Bass to what would normally be a setting of 0 -2 in a normal spec Marshall tonestack, which I would never set my Bass that low anyway. So I will just leave it there for the time being.

As for that C24, that is quite odd. The original owner did not do any mods to this as it was basically still brand new when I got it it. Unless I jumpered that cap in the past? I will have to flip the board to check it. Or maybe there is some other mod I did that is making this cap bypassed? But the only mod I remeber doing to the tone circuit was that 100K mid pot.


----------



## mickeydg5

When I said shorted I meant as in bad, internally shorted. Check that just in case.


----------



## RickyLee

mickeydg5 said:


> When I said shorted I meant as in bad, internally shorted. Check that just in case.



That sounds like I will physically have to work at that one LOL.

Yeah, I would have to unsolder one end to check it. I do not see any other possible reason that it could be.

Standby, as I am still tinkering with the preamp B+. I clipped the dropping resistor R62 1K and stuck a heavy duty pot in series with the resistor and lowered my cathode follower plate voltage to under 330V. LOL

I am taking some more voltage readings. Figuring I will solder in a new dropping resistor to the value of the pot + R62.


----------



## mickeydg5

RickyLee said:


> Standby, as I am still tinkering with the preamp B+. I clipped the dropping resistor R62 1K and stuck a heavy duty pot in series with the resistor and lowered my cathode follower plate voltage to under 330V. LOL
> 
> I am taking some more voltage readings. Figuring I will solder in a new dropping resistor to the value of the pot + R62.


 
I read your other thread concerning B+ and plate voltages. Those voltages may be in line for that given 122Vac from the wall. You need to search around and ask some other DSL users for verification on voltages.

Dropping the voltage that much will affect V1 and V2 as well.


----------



## RickyLee

mickeydg5 said:


> I read your other thread concerning B+ and plate voltages. Those voltages may be in line for that given 122Vac from the wall. You need to search around and ask some other DSL users for verification on voltages.
> 
> Dropping the voltage that much will affect V1 and V2 as well.



All the other preamp voltages pins 1 & 6 are just over 200V. Puts the preamp closer to early Marshall specs. Funny thing is I played the amp after dialing in that added resistance on that pot, and seemed like the amp had more sweet crunch. So I moved the value of that pot between the original R62 value and 10K while I was playing and heard no change.

You would think that lowering the entire preamp B+ by 50V would give it just a bit more breakup. As it is biasing those gain stages a bit hotter.

And last year I had lowered the B+ a bit by increasing R63 from 4.7K to 10K. So now I will have R62 at 10K as well. That is also more in line with early Marshall specs.


----------



## gazzamarad

Hi dsl lovers. I must say a big thank you to Jason77 Page26 and Jensbrix page 25 for suggesting the NFB R19 mod. I agree that it is maybe one of the best simple singular mods for changing tonal character of my dsl100. Its like engaging the deep switch again but with much better tonal response in the way of bass"smoothness" and control. Bass eq (at home) is now on 2 as opposed to 7 or 8 and I have been able to pump the middle to 10 would you believe and it sounds nice and rounded all over. Even the lead 1 and 2 sound fuller. ( The joey lead channel mods have been done here) Thanks again guys......p.s.....
I have stock transformers with the 3h choke mod. Didn't like the o/p mercury mags mega transformer as it seemed to sterilise the sound somewhat. Any suggestions anyone on the best or preferred o/p transformer in regards to honest tonal improvements to the stock tranny please would be most appreciated. I guess its down to a Lydian, marstran, heyboer or dagnall plexi clone? Thanks again.....Gaz


----------



## rockgod212

im pretty happy with the marstran in my amp....


gazzamarad said:


> Hi dsl lovers. I must say a big thank you to Jason77 Page26 and Jensbrix page 25 for suggesting the NFB R19 mod. I agree that it is maybe one of the best simple singular mods for changing tonal character of my dsl100. Its like engaging the deep switch again but with much better tonal response in the way of bass"smoothness" and control. Bass eq (at home) is now on 2 as opposed to 7 or 8 and I have been able to pump the middle to 10 would you believe and it sounds nice and rounded all over. Even the lead 1 and 2 sound fuller. ( The joey lead channel mods have been done here) Thanks again guys......p.s.....
> I have stock transformers with the 3h choke mod. Didn't like the o/p mercury mags mega transformer as it seemed to sterilise the sound somewhat. Any suggestions anyone on the best or preferred o/p transformer in regards to honest tonal improvements to the stock tranny please would be most appreciated. I guess its down to a Lydian, marstran, heyboer or dagnall plexi clone? Thanks again.....Gaz


----------



## Jason77

gazzamarad said:


> I must say a big thank you to Jason77 Page26 and Jensbrix page 25 for suggesting the NFB R19 mod...Any suggestions anyone on the best or preferred o/p transformer in regards to honest tonal improvements to the stock tranny please would be most appreciated. I guess its down to a Lydian, marstran, heyboer or dagnall plexi clone? Thanks again.....Gaz



Glad it worked out for you. It sounds great in my 50 but I've yet to do it in my 100.

As for transformers, I have the Lydian (which is a Heyboer) in my 50 and it sounds great.


----------



## Elitevacuumtubes

Is there a schem I can follow?


----------



## motocooney

Hey, I have a dsl 100...I've only done a few things.

-removed c12 front board
-jumpered r12 and r20
-Classic Tone choke

But...lastnight I tried just desoldering one leg on c4 to see if I liked it.
I also jumped c8.

I'm not 100% percent but I swear the amp isnt as loud overall now. Also, the crunch setting seems to have less gain.

Also, I noticed that the Mullard RI 12ax7 I have in v1 seems to be very dim. 

Any ideas?


----------



## motocooney

Jason77 said:


> As for adding the cap to the NFB resistor, it basically adds clean low end to your signal, making the low end clearer and punchier. It works similarly to how the presence control adds more highs. To me, it has a more natural feel than the deep switch. I like .0047uf but if you want more lows, you could use a .0033uf or even a .0022uf.
> 
> The NFB resistor is R19 on the rear board. You just need to disconnect the leg that connects to the 4ohm spade connector and solder the cap in between.


 
This may be a dumb question but.....I use the 16ohm speaker output. Will this mod work for me?......It sounds like exactly what I'm looking for.

thanks


----------



## RickyLee

motocooney said:


> This may be a dumb question but.....I use the 16ohm speaker output. Will this mod work for me?......It sounds like exactly what I'm looking for.
> 
> thanks



It will work for all impedance settings.


----------



## motocooney

cool thanks ricky....I tried the r19 resistor mod and it did exactly what I was hoping it would. Just a bit more low end. This mod alone had a huge effect on my tone.


----------



## myfriendzeppelin

Hi guys,

Long time listener, first time caller:

I have a big problem with my DSL100. I was going to replace C12 on the main board, so I removed the original. I then realized that the replacement I had was the wrong value, so I put the original back in. I thought I did a clean job at first, but then I put everything back together and turned the amp on; all that came out was a hum (no signal). The hum is directly affected by the volume knobs, so it can be turned all the way down. Both channels (all four modes) are the same. I took the amp apart again and noticed that C13 had shorted out. After trying to replace things and double checking everything, the soldering is a little messier, but everything is making contact. Still, just hum. I don't know if the replacement for C13 is good or not, so I'm going to get new caps tomorrow. 

Any clues? Everything else looks fine and I tried replacing all of the preamp tubes with a different (known to be working) set.

Thanks!


----------



## motocooney

myfriendzeppelin said:


> Hi guys,
> 
> Long time listener, first time caller:
> 
> I have a big problem with my DSL100. I was going to replace C12 on the main board, so I removed the original. I then realized that the replacement I had was the wrong value, so I put the original back in. I thought I did a clean job at first, but then I put everything back together and turned the amp on; all that came out was a hum (no signal). The hum is directly affected by the volume knobs, so it can be turned all the way down. Both channels (all four modes) are the same. I took the amp apart again and noticed that C13 had shorted out. After trying to replace things and double checking everything, the soldering is a little messier, but everything is making contact. Still, just hum. I don't know if the replacement for C13 is good or not, so I'm going to get new caps tomorrow.
> 
> Any clues? Everything else looks fine and I tried replacing all of the preamp tubes with a different (known to be working) set.
> 
> Thanks!


 
When you pulled the mainboard, did you unhook any connectors?
Are you sure everything is plugged back in correctly?

Why were you messing with c12 on the mainboard ( i assume mainboard is tube board)?


----------



## RickyLee

myfriendzeppelin said:


> Hi guys,
> 
> Long time listener, first time caller:
> 
> I have a big problem with my DSL100. I was going to replace C12 on the main board, so I removed the original. I then realized that the replacement I had was the wrong value, so I put the original back in. I thought I did a clean job at first, but then I put everything back together and turned the amp on; all that came out was a hum (no signal). The hum is directly affected by the volume knobs, so it can be turned all the way down. Both channels (all four modes) are the same. I took the amp apart again and noticed that C13 had shorted out. After trying to replace things and double checking everything, the soldering is a little messier, but everything is making contact. Still, just hum. I don't know if the replacement for C13 is good or not, so I'm going to get new caps tomorrow.
> 
> Any clues? Everything else looks fine and I tried replacing all of the preamp tubes with a different (known to be working) set.
> 
> Thanks!



Just noticed your post. Did you get the problem fixed?


----------



## myfriendzeppelin

I only removed one connector, but it's back in the right place. Everything I did was on the tube board, yes. I bought replacements for both C12 and C13 and put them in. I even bought a conductive pen to retrace the places where the caps connect to the board. Is it possible that a resistor or another cap has gone bad without showing any physical signs?


----------



## RickyLee

These DSL/TSL PCB's have very close solder pads. Very easy to short something out when soldering. It is almost a situation where a magnifying glass, very thin gauge solder and a very small diameter with a sharp point solder tip are needed to work on these amps.

I was leaning towards the idea, that you shorted adjacent solder pads together and you still have solder touching two or more pads of different paths/traces together. And/Or you lost/lifted a solder pad in there as well.

Did you try removing ALL solder on the suspect area as well as the neighboring pad and try it again? A good solder sucker will work here as I had this happen on my DSL as well. Or soldering braid as some people go with.


----------



## myfriendzeppelin

RickyLee said:


> These DSL/TSL PCB's have very close solder pads. Very easy to short something out when soldering. It is almost a situation where a magnifying glass, very thin gauge solder and a very small diameter with a sharp point solder tip are needed to work on these amps.
> 
> I was leaning towards the idea, that you shorted adjacent solder pads together and you still have solder touching two or more pads of different paths/traces together. And/Or you lost/lifted a solder pad in there as well.
> 
> Did you try removing ALL solder on the suspect area as well as the neighboring pad and try it again? A good solder sucker will work here as I had this happen on my DSL as well. Or soldering braid as some people go with.



I did indeed lose both soldering pads while removing one of the caps. They came off like there was nothing holding them on! They only came off on the top of the board, though. On the bottom, everything looks like it should work. I WILL get my magnifying glass out, though. Thanks for the tip.


----------



## RickyLee

myfriendzeppelin said:


> I did indeed lose both soldering pads while removing one of the caps. They came off like there was nothing holding them on! They only came off on the top of the board, though. On the bottom, everything looks like it should work. I WILL get my magnifying glass out, though. Thanks for the tip.


 A continuity checker and the schematic will do the trick in figuring out if you have some shorts or accidental jumpered terminal connections there. Sometimes some of those extremely close pads are on the same trace/electrical path. So checking the schematic first will save you some panic there.


----------



## xjbear

The plate bypass cap mentioned on the net possibly dulls the clean channel(390p across R1) but certainly helps darken up the DSL, I was thinking why not do a Plate bypass elsewhere in the amp like on V2B? Just bypass R32 with an appropriate cap, I've included a link to a PBC calculator, just not sure of V2B's input impedence.

What do u all think?

Plate bypass calculator
Plate Bypass Capacitor Calculator

schematic
https://docs.google.com/open?id=1HmmZ30qW5iSbEHPjfIZoefFMriCiVD35dtW_pKFa4wsCLf-udFMlmgl8d5TC


----------



## xjbear

forget the post above, I played with the tone stack and got what I want out of it.
I've done all the Joeys mods and still wasnt quite satisfied with the tone, not enough mids, so I clipped out R35 (r35 sets the Q of the mid band) and put in a 5.6k resistor on the leg of an 25k Log pot and that sweeps the mids, looks like leaving it at 5.6k(pot all the way down) is right up my alley, super heavy lowend mids which they overpower the harsh highs and make them sit in the mix better now, also tightens up the lows alot.

turns out that you can turn the mid scoop switch into a mid boost very easily, replace R36 (68k)with a 27k resistor, replace R35 with a 5.6K resistor, switch (pushed In) your at stock DSL settings (33k total), switch out you have a mid boost (5.6k), Cake! or just put the pot in there and sweep it whatever


----------



## xjbear

well after playing with this mod I believe it is the be all end all of tone searching for me, the eq is now so interactive, I can tweez it perfectly to drive my 1960av cab now, before it was so 1985 and I wanted 1972 and 2012 respectively lol


----------



## xjbear

Tsl atomium stuff


----------



## jball1985

Does anyone know which resistors are the grid blockers for the dsl 50?


----------



## mickeydg5

jball1985 said:


> Does anyone know which resistors are the grid blockers for the dsl 50?


 
They are usually R66 and R70 which have one side connected to pin #5 of each power tube.

Are those the ones in question?


----------



## guitargoalie

The mods that I have done are 

Tube board:
C12 = 1uF
R13 = 100K
Front board:
Jump R20 
R21 = 220k
C12 removed


This was done by a tech, so I can't say I know what each mod specifically does, other than help get it closer to an 800 (as recommended by a forum member) 

The green channel has more gain and the mids are better on both channels. On the red channel I can't even play with the gain past 2 for my style of music, its way too hairy distortion. Should I consider different preamp tubes (currently jj's), or is there a certain cap or resistor that affects ultra channel's gain?


----------



## guitargoalie

ignore that ^ I think I figured it out


----------



## diesect20022000

guitargoalie said:


> ignore that ^ I think I figured it out


 it's a long shot (i'm in the very low income bracket) but if i ever get the money i definitely want a build from you man. the tones and aesthetic (and board/wire layout) are immaculate. i have a fetish for amp circuits. i collect pix and plan on making posters of them (and collages) to puut on my walls and just from an aesthetic point of view i can say your layouts are some of the most clean and thoughtful i've seen. but yeah the tone's what makes me want to get some gear sold already so i can get a custom build from you one day.

you francois and a few others......amazing work and great people.


----------



## rockgod212

well my dsl is back on the bench, i seem to get an annoying crackle from my v30's when i hit certain notes. i dont know if its just resonating, pushing the speakers too much, or whats going on. 

other questions though for jcm2-60-02(iss5)

r16- grid to ground resistor, can it be removed or adjusted?
r20/ r27- coupler to ground resistor, can it be removed or adjusted?
r18- grid to ground resistor, can it be removed or adjusted?
c18- what does this cap do, is it some sort of filter or shelving freqs?
how do the LDR's work?


----------



## rockgod212

never mind, i figured it out. changed a few things though. c10 back to 4n7, 
r21= 1m to make the pot 500k ala soldano, added a brite cap switch to red channel= 250p, 470p, 1n. now red 1 and red 2 are more balanced, although i prefer red 1 mode with all the mods i did to my amp.



rockgod212 said:


> well my dsl is back on the bench, i seem to get an annoying crackle from my v30's when i hit certain notes. i dont know if its just resonating, pushing the speakers too much, or whats going on.
> 
> other questions though for jcm2-60-02(iss5)
> 
> r16- grid to ground resistor, can it be removed or adjusted?
> r20/ r27- coupler to ground resistor, can it be removed or adjusted?
> r18- grid to ground resistor, can it be removed or adjusted?
> c18- what does this cap do, is it some sort of filter or shelving freqs?
> how do the LDR's work?


----------



## Ghostman

I put the Joey Mods back in today, and since I'm not chasing a cable issue, it sounds a lot better. However...

..I have some fizzyness on all channels when I strike a note. The harder the strike the more apparent it's there. Sounds like a little bit of raspyness. Almost like a blown speaker but the speakers are good.

Any ideas?


----------



## gh9597

OK....I just recenty purchased a DSL 100 head and 1960cab from a friend who was needing some money. Something tells me I think he got the better end of the deal. I have been playing a Mesa Boogie Nomad 45 for 10 years now. Ive never owned a Marshall. For some reason this Marshall is not cutting through like I think its supposed too. It seems I have to crank the gain and volume up on the O.D channel to hear it. My mesa just rips through this cab and my volume is very low. Channel one clean I have gain and volume almost maxed out. The crunch on channel one sounds awesome. 2nd channel has no bottom end. Its very thin and its just not coming through. My volume is on 3-4 and gain is on the same. Is this normal or do I have something going on. Just change power tubes and preamp tubes.


----------



## rockgod212

i have bypassed my fx loop by removing RL3B and it sounds great without the loop, but does anyone know how to energize or de-energize RL3B with just a switch added, as it looks like all the relay circuitry is there, just need a switch to switch it. or am i wrong about this?


----------



## ChrisYoung

na


----------



## xjbear

I did all the Joey mods, still wasn't real happy with it. Tried some other cap roll of mods on the gain and volume pots, still not much help. Wasn't until I changed some tone stack values that things got right, although I have lost some versatility(who cares) it pushes air and does the plexi thing on the clean/crunch with all knobs dimed like it should now. The lead and lead2 are perfect as well. 2 100pf silver micas in parallel in c20, c22 change to 4.7n or .0047 polycap, r38 to 560k or 1m and 1.5m paralleled if you don't have a 560k, c12 is out and r20 is jumper end per JoeyMod.


----------



## xjbear

Along with a previous mid Q mod I did this is the way for doom sludge metal


----------



## xjbear

Here's the mid q mod, used a micro stack knob for authenticity


----------



## CRunCH

TwinACStacks said:


> Popcorn's good. Anybody got some salt?
> 
> TWIN



TWIN, I've been lurking this thread for months and must have always breezed over this comment. Nice stiletto ... and since I'm not in NY, I'll have a 48 oz Big Gulp with that popcorn.


----------



## xjbear

The transformer swaps are really the best thing you can do. The originals are pretty weak


----------



## vincetecnic

would It be possible to have V1a for boosting the green channel also?
Would be cool to have V1A boosting both the Red and the green channel(to make It as a solo/lead boost otion).


----------



## vincetecnic

I have something similar on my Plexi,It works great!


----------



## maltone

*Joey Mods Completed...*

I just finished doing the Joey Mods today with a friend who's an electrical engineer.

We did the following:

*FRONT BOARD*:
1M resistor from wiper to ground on VR3
R20: removed and jumpered
C10: replaced with .0022 uF 500v
C12: replaced with 150pF @ 63v, 

*MAIN BOARD*:
C46: replaced with same value of 22pF @ 1000v
C9: replaced with 1000pf
C12: replaced with 1uF @ 63v (_while the original on-board cap read in at 100v_ —?)
BIAS RESISTORS REPLACED: 
R67, R69 with 220K, 1/2 watt, metal film @ 1% 
R68, with 33K, 1/2 watt, metal film @ 1%
R77: original stayed in amp because it wasn't a value of 10K as stated in our schematic, but 3.9k instead. We weren't sure if it was a good idea to replace this with a 10K value — and why would you? — Please someone explain.

OUTPUT TRANSFORMER: Installed a ClassicTone 40-18055
DC FILTER CHOKE: Installed a ClassicTone 40-18058 

*Comments and Afterthoughts*: 
After turning the amp on, we got that god awful HOWL, and then turned it off, realizing something was wrong. We found the online post on swapping W3 for W4. Sure enough, that solved the issue.

The plate voltage reading we got was 461, where as a few weeks ago with the stock Dagnall C7030, it was 466.

PERCEIVED TONAL CHANGES:
I do notice that the Green clean and crunch channels are a bit clearer, have a tighter feel, less BOOMY, more articulation and definition. The flub that was there before we did the mods has been lessened.

I'm liking the GREEN channel. The RED channel is also more useable now, especially on LEAD 1 MODE at lower volume, and less gain. BUT we were dumbfounded when I turned the volume up on LEAD 1 — up to 4-5, and the gain up to 3. We got the most obnoxious and squealing high pitched feedback - whereas I didn't get this with my guitar before the mods. 

UPDATE: Ignore this, the feedback is gone completely. I think it was some kind of acoustic induced feedback, where I was standing, how the speaker was angled, near the head, the room. Now the amp and speaker have been setup where I normally sit and play, and that squeal is gone. 

Last night my brother in law and I AB'd his "stock" 2007 DSL100 against my "modded" 2008 DSL100, and mine definitely has more detail and seems clearer, more definition. But the tonal "feel" of the amps is still very similar, and still very Marshall.

We plugged in his Dean Z, exactly like this one: http://i5.photobucket.com/albums/y170/warmitag/My%20Gear/Armitage_Dean_BB_Z.jpg. It has a DiMarzio DP100 in the bridge. OMG. WOW. It sounded amazing. I've never heard a pickup with THAT much output. Using the volume control on the guitar cleaned it up, but still with some dirt, and it allowed us to set the volume and gain on the GREEN+CRUNCH channel much lower than through my Gretsch. I'm simply amazed at how good that combination sounds.

Much appreciated.


----------



## AdaBoomer

Longtime lurker, first time poster. Just want to say, pulled the C12 from the front board and the red channel sounds amazing. Finally, two awesomely voiced channels to use and the EQ does work better (more closely) with both channels. Should have done this long ago. Long live the Dual Super Lead.


----------



## timo3452

My main board is a jcm2 60-00 so will the joey mods work on it


----------



## ledvedder

OK, I've had my DSL 50 for about 2 years now. The only mod I've done is the C12 mod. I have a choke that I haven't installed yet. I'm also looking into upgrading the OT. I've been reading and hearing a lot about the Fortin mods. What would you guys suggest? I seem to always go for a Van Halen type of tone, but with the ability to get heavier, in the realm of Alice in Chains type stuff.


----------



## jensbrix

timo3452 said:


> My main board is a jcm2 60-00 so will the joey mods work on it



Yes, but some components might have different names (mine was a '97 version and had different names).

Compare the two schematics and note the new names of the parts you need to change, the mods still apply for your circuit.



ledvedder said:


> OK, I've had my DSL 50 for about 2 years now. The only mod I've done is the C12 mod. I have a choke that I haven't installed yet. I'm also looking into upgrading the OT. I've been reading and hearing a lot about the Fortin mods. What would you guys suggest? I seem to always go for a Van Halen type of tone, but with the ability to get heavier, in the realm of Alice in Chains type stuff.



I would start out with lowering the first cathode bypass cap to 1uF as in Joey mods, and take it easy from there, in my oppinion this is the best of the mods.


----------



## ledvedder

ledvedder said:


> OK, I've had my DSL 50 for about 2 years now. The only mod I've done is the C12 mod. I have a choke that I haven't installed yet. I'm also looking into upgrading the OT. I've been reading and hearing a lot about the Fortin mods. What would you guys suggest? I seem to always go for a Van Halen type of tone, but with the ability to get heavier, in the realm of Alice in Chains type stuff.



Anyone? Bueller?


----------



## timo3452

my tube board is jcm2 60-00 iss 20 but I dont see that schematic on the link at the first page of this thread ,would I be ok to use another if so witch one.


----------



## gazzamarad

Hey xj bear so the powersoak is a cool thing for the dsl? Has anyone had a mod done with a master volume installed controlling both channels? Or maybe even 2 MV's controlling each channel individually, like the JVM 50 head? Would this effectively do the same thing or similar as a poower soak (attenuator)? I see on ebay you can buy so called attenuators for about 50 bucks but I am suspicious that they may be the same as the volume pot on your guitar....thoughts please dsl fans...kind regards...Gaz from down under


----------



## Derek S

Kinda a silly question but will any of these mods apply to the 50th DSL 1 watt or is that way too early to know? I love the green channel of the 50th both for its cleans as well as using pedals - but that red channel, I dunno, needs some help. I'd be happy to post a detailed, high rez pic of the board if that would help.


----------



## invictarocks

*Marshall JCM2000 DSL 50 Choke*

Thank you gentlemen, for inspiring me to dig into my amp! I replaced a whole mess of caps (with stock values for now) and installed a choke.

WOW

The amp used to be very noisy and would start to really squash after "5" on the ultra master. Now it just keeps getting louder.

LOVE IT

I ran across a mod to put the deep switch function on a pot, but can't find it again. Anyone here know how to do that one?

Thanks again guys. You ROCK!

-=Vern


----------



## rockgod212

*Re: Marshall JCM2000 DSL 50 Choke*

the pot doesnt go on the deep circuit, its a seperate resonance mod circuit from the other end of the nfb.


invictarocks said:


> Thank you gentlemen, for inspiring me to dig into my amp! I replaced a whole mess of caps (with stock values for now) and installed a choke.
> 
> WOW
> 
> The amp used to be very noisy and would start to really squash after "5" on the ultra master. Now it just keeps getting louder.
> 
> LOVE IT
> 
> I ran across a mod to put the deep switch function on a pot, but can't find it again. Anyone here know how to do that one?
> 
> Thanks again guys. You ROCK!
> 
> -=Vern


----------



## rockgod212

ok, so i returned my amp to all stock, except for:

1. added a real resonance control- 1meg linear pot with a 2n2 res. cap, sounds much better than the deep switch circuit, more natural sounding
2. filters- 
mains and screens are stock
PI= 68u
TS= 47u
gain stage filters= 15u each
3. r63, r62= 10k.....much less voltage on PI and CF and lowers voltage on the gain stages a bit as well, sounds less linear/ hi fi, sounds great
4. chassis mounted the power tube sockets and rewired accordingly, now all the power tube heat is off the board, it was a pain in the ass to do, but worth it.
5. 1 ohm bias resistors on each tube now with the classic marshall bias circuit- 25k single chassis mounted pot- much easier to bias and much more stable bias.
6. vishay couplers and sozo's in the TS
7. switchable peaker caps and switchable brite caps on red lead's

still have some bugs to work out, but this dsl 100 is ready to rock once. more.


----------



## Guitar@home

Am I the only one that thinks the JCM2000 DSL is good the way it is. Mine is a 100% stock 2001 "other than tubes". It is my 3rd DSL in 3 months I did not like the first 2, a 2004 DSL100 and 2006 DSL50 both were way too uncontrollably bright, and I could not get a sound I could live with. I had given up on DSLs, but took the 2001 in on part trade and it sounded perfect even with having most of the bad stuff according to the mod recommendations like the 220k grid blockers, but I think that may be contributing to the much warmer sound of my 2001 or is that crazy talk? It dose have some Bias drift as it heats up it starts out at 82 then after Ten minutes of hard playing it is at 85 after one hour it seems to be stable at 87. Do you guys think I should leave this one alone or give some mods a try?


----------



## RickyLee

Guitar@home said:


> Am I the only one that thinks the JCM2000 DSL is good the way it is. Mine is a 100% stock 2001 "other than tubes". It is my 3rd DSL in 3 months I did not like the first 2, a 2004 DSL100 and 2006 DSL50 both were way too uncontrollably bright, and I could not get a sound I could live with. I had given up on DSLs, but took the 2001 in on part trade and it sounded perfect even with having most of the bad stuff according to the mod recommendations like the 220k grid blockers, but I think that may be contributing to the much warmer sound of my 2001 or is that crazy talk? It dose have some Bias drift as it heats up it starts out at 82 then after Ten minutes of hard playing it is at 85 after one hour it seems to be stable at 87. Do you guys think I should leave this one alone or give some mods a try?



I have had a 2005 DSL100 for quite some time now. I did a grip of mods to it to get it closer to that "sound in my head" if you will. Mainly I was trying to rid the amp of that plastic fake fizz that was there when it was stock.

Then last month I picked up a stock 1998 DSL100. Did a minor repair to it and it was good to go. When I first played it, I was blown away by how different it sounded from my 2005 when it was stock. It must be close to yours as I have no urge to change anything on this one. Well, actually I did swap the 220K grid blocks for 5.6K. But then after that swap I noticed it did lose a bit of that smoothness it had to it. But this one is badass in stock form basically.


----------



## gazzamarad

Hi guys. Adding to xjbears post re: power soak/attenuator, I recently decided to try a volume pot (glow baby via u tube) in the send and return effects on my dsl 100 (2006model). A quick simple non invasive and very cheap idea or mod. With the volume pot (glow baby) set at 3 oclock I found the best improvement. It allowed me to turn up the vol and gain on both channels giving me more preamp tube distortion and a ballsier sound without volume increase. A bit less wood and more growl. For my sound anyways. I was wondering if anyone else had tried this simple idea. I guess an even better idea would be to put an eq pedal there instead and run the volume into the minus db side of the graphic and the individual eq sliders wherever it may suit, giving you a tonal control variance as well as a master volume control. (The idea came from a mate who has a two channel jvm 50watt head where he runs the volumes on the channels at about 3 oclock and his overall MV on two to three. He gets a big sound this way. He also has a 12at7 somewhere in the the preamp stage which takes that high end fizz and top outta the overdrive on his amp.) Anyway my dsl now has a master volume of sorts which gives me more tonal options....Opinions would be most welcome. P.s. I am sure my mod is just a volume pot in a box. I can't get the screws off the back as they won't budge which leads me to the conclusion that it is what it is...........


----------



## rockgod212

i think mine is a 2000, and i think all the really good sounding dsl's all had the normal looking jcm 800 rocker switches, it seems the problems in these amps started popping up with the models that had the goofy looking rocker switches and such, just speculating here. i think the transformers changed on the later models as well, because i here alot of people saying they run 463 or so on the plates, but i run a solid 490vdc on the plates on mine (stock dagnall), so what gives? my dsl finally sounds great again. labor of love these amps are, as i rebuilt the thing 3 times, but my amp did need a few tweaks here and there.


----------



## invictarocks

*Re: Marshall JCM2000 DSL 50 Choke*



rockgod212 said:


> the pot doesnt go on the deep circuit, its a seperate resonance mod circuit from the other end of the nfb.



How do I do it?


----------



## hadan

I'm gutiarist from Vietnam, thanks for all, i love threads and this forums.

My DSL the best on the planet 

Moded:
1M Resistor from Wiper to Ground on Vr3
C12 REMOVED
C10 replace with .0022 uf
R20 Remove and JUMPER

Updated:
Nichicon & ELNA audio filter capacitor
Orange drop capacitor
Mercury Magnetics Output / Power / Choker (Super stack)

FIXED:
Drifting Bias fix and repairs.


----------



## TwinACStacks

Wow. We created a Monster thread here. Glad you guys liked it and the DSL as well.

 TWIN


----------



## Stymie13

TwinACStacks said:


> Wow. We created a Monster thread here. Glad you guys liked it and the DSL as well.
> 
> TWIN



Indeed you did. Since originally modding it I've been through a Mesa Recto, an original 5150, and an Orange R30 all of which are amazing amps. But my Joey modded DSL 100 is still my favorite amp. I've said I would never sell many things and then ended up selling them. This one however, I know is a keeper. It will be passed down to my son.

Thanks Twin and Joey(and everyone else)!!!


----------



## chuckharmonjr

One thats really helpful is to label all the cables with Brady Wire Labels. I labeled all of mine according to where they plug in on a board. For example....a cable end that plugs into plug 8 on the main board has a label by the plug that reads M-8. Tube board plug 1 would be T-1. Makes it real easy to put everything back together.


----------



## dango

I have loved reading this forum and thinking about (and re-thinking about) modding my 98 DSL50. So many great ideas.

Of course I never got around to doing any of the mods, but one day...

In the meantime, I played a pretty serious outdoor festival this morning with the stock DSL50 thru a Harry Kolbe 1x12 cab - some of the best tones I've ever gotten, the sound company guy who owns a collection of vintage and modern Marshall's was like, whoa, what did you do to that thing? Too funny.

The clean channel sounded phenomenal, the red channel equally great, they worked off each other brilliantly. Volume differences are noticeable (have to turn the clean side up much hotter to get to a balanced point across the channels), but no big deal. I could have played a jazz gig with these clean tones, no joke (we did a bunch of steely dan covers, you would not have believed I was using a Marshall head on that stuff).

I think this amp has sounded better and better over time, it seems to have "broken in" from when I originally bought it in 2000 - is that even possible?. A few years back I brought the bias down (to mid 30's) which took some harsh edge off without losing too much punch - less of the ice pick - but that's about it. The amp just sounds rounder/better to my ears. Go figure.

Aside from the fact that (a) the amp is just a hair too loud for using it all the time at home, and (b) the post volume loop sometimes drives me nuts when using effects, this one is a real keeper. 

Rock on team DSL!

Best,
Dango


----------



## BenediktSchlereth

HI
i´m a newbie and i´ve read all pages, as you might expect i´m a little conufused right now what mod would work for me.
I´m playin my dsl through a greenback 4x12 and Gibson les Paul 58.
i got the amp for 400€ so i thought well buy that thing. Now ´ve played it and i´m quiet satisfied but not too much Since i´ve got a 1987x too. 
Well by comparing the two i noticed that the dsl is way to bassy and flubby without having that great tight bass warmth and rock solid mid range.
so as you can see i´m mostly interested in modding the green channel but would consider the red one too to get more full and clear sounding. Gain on red is ok for me but would like a litte more in the green.

so it would be absolutly great if you could tell me a round up with some mods and what they actually do, that would get me as close as possible into that plexi land.

all the best

Benedikt


----------



## mott555

This thread is mega-long. Is there a summary somewhere of what these mods accomplish? Or perhaps a before-and-after comparison video?


----------



## TwinACStacks

mott555 said:


> This thread is mega-long. Is there a summary somewhere of what these mods accomplish? Or perhaps a before-and-after comparison video?



 Mott, I started this Monster, Look at my first post. It tells you the Mods, What they do, and where to source some of the parts. I can't believe someone has not used the Dagnall C1998 O. Transformer yet, as far as I can tell. It's a PLEXI xformer and will take these mods to a Whole different level... You can either use an original, but there are few, or get a Clone from Marstrans.

 TWIN


----------



## javier pintos

hi guys

hey i´m looking into having the same lows on the classic channel as in the ultra channel, i´m (finally) about to install the mode shift on the classic chanel but one thing that bothers me some is that when i change from the clkassic to the ultra the lows are more present in the classic channel so i have to reach to the amp and i really want to avoid using an eq peddal, i will be removing, well actually installing a switch on the r13 or whatever it is on the crunch mode to increase the gain a bit, but i still want to have the ultra 1 similar on the lows for higher gain stuff without reaching to the amp

i know that i should read the whole thing but i just get lost whenever i start doing that, too much info 

cheers


----------



## Grogshla

i would consider the mods but just can't bring myself to doing it. I have enough problems with my amp as it is. I can imagine getting a tech to work on it would stuff it up even more most likely. Besides I have gigs every week nearly and don't have time to stop, mod it and test it between gigs.
It would be interesting to hear some sound clips of people who have done the joey mods.


----------



## javier pintos

javier pintos said:


> hi guys
> 
> hey i´m looking into having the same lows on the classic channel as in the ultra channel, i´m (finally) about to install the mode shift on the classic chanel but one thing that bothers me some is that when i change from the clkassic to the ultra the lows are more present in the classic channel so i have to reach to the amp and i really want to avoid using an eq peddal, i will be removing, well actually installing a switch on the r13 or whatever it is on the crunch mode to increase the gain a bit, but i still want to have the ultra 1 similar on the lows for higher gain stuff without reaching to the amp
> 
> i know that i should read the whole thing but i just get lost whenever i start doing that, too much info
> 
> 
> cheers


 
c´on guys someone must know  and now summer vacation is almost up kids are going back to school and i will have again a chance to get innto the amp


----------



## CraigJC

This may have been covered before but...LOTS of information here to go through...

I've done the C12 mod and was wondering if there is a mod to lower the gain of the red channel, specifically Lead 1.

I'm aware of tube swaps to accomplish this, but I have more NOS options sticking with the old 12AX7.

Thanks guys!


----------



## armandin

Hi People.

I have a DSL401 -I really like everything except the top end (on all channels) which ruins an otherwise fine sound, I have changed the toobs to JJ (including gold pin for V1), installed a Vintage 30 and it still sounds just as cheap and nasty as before.

I take it that none of these mods in this thread can be adapted for the 401?

Many thanks in advance,

Armandin


----------



## chadjwil

The 401 is a bit of a different animal, but if you can make your way around a schematic and have a little bit of electronics knowlege you will find that the majority of the tweaks in this thread are applicable to the 401 as well...just not the same part designations. If you're interested in some particular mods feel free to ask. Someone will take the time to help you through it I'm sure.


----------



## Stymie13

chadjwil said:


> The 401 is a bit of a different animal, but if you can make your way around a schematic and have a little bit of electronics knowlege you will find that the majority of the tweaks in this thread are applicable to the 401 as well...just not the same part designations. If you're interested in some particular mods feel free to ask. Someone will take the time to help you through it I'm sure.



OK, since you offered I'm going to pull the circuit board on my 401 to open up the power tube holes in the chassis to accommodate TAD EL84s and figure while I'm in there I'd love to:

-reduce the harsh brightness on OD1/2
-reduce the overall gain on OD1/2
-tame the boomy bass on classic channel

I did some mods on my 100 as I posted way back in this thread and am really happy with it but don't know which position values would achieve the same results in the 401. I miss the good ol' days when Joey and Lane (among others) would generously enlighten us with their knowledge and experience. Anyway, I appreciate anything you're willing to share.


----------



## guitargoalie

Aside from those videos buggs posted a long time ago, I have not seen one video or sound clip to show how the newly modified channels sound! Every so often I think about doing these, but I'd like to hear to get a basic idea first. I love my DSL, but sometimes I get picky and things are missing that I hear in other marshalls


----------



## armandin

chadjwil said:


> The 401 is a bit of a different animal, but if you can make your way around a schematic and have a little bit of electronics knowlege you will find that the majority of the tweaks in this thread are applicable to the 401 as well...just not the same part designations. If you're interested in some particular mods feel free to ask. Someone will take the time to help you through it I'm sure.


 

Thanks, I will download the schematics and if I can get the basic idea, then will try to replicate some of the mods on here.

Thanks again,

A


----------



## JEB

I'm thinking about installing a switch on my DSL40C across the C19 position.

I want to install an on/off/on switch with the stock 470pF cap in one position and 120pF in the other position.

My big question is: where do you guys recommend mounting the switch?


----------



## alexmallen

hi there, I'm looking to lose the fizz on my dsl 15c. What mods did you complete ? thanks !!


----------



## alexmallen

Hi all,
I'm new to the forum. I recently have bought the Marshall DSL 15c after upgrading to the tube amp from a solid state! However the DSL seems to have excessive fizz...The only way to get a classic vintage rock tone is to turn down the volume and tone. Once the gain is over say 9 o clock it's basically not usable, the fizziness just becomes unbearable. I'd like to have a bit more range on the OD channel. I've read some threads and some have suggested modding it, some suggested changing the preamp tubes. I still want a high gain Channel capable of Megadeth, Anthrax and more but i also want to be able to get classic tones like ACDC, Led Zepplin and Deep Purple. Any suggestions? I'm new to modding amps and installing tubes/ speakers so i will be bringing it to my tech to have a look at and hopefully he can talk me through it while he does it so I will know from then on. So basically all I want to do is rid the fizziness but keep the gain and be able to dial in a creamy warm OD Eq. Does anyone have a link to another thread or even better a solution ? Thanks everyone!


----------



## mott555

I want to do these mods when I get around to fixing the FX loop of my DSL, since I'll have to open it up anyway. Well I have a 5-day weekend coming up. I'm toying with the idea of mounting a switch inside the headshell for "Stock" and "Modded", and use it along with some relays to swap out the relevant components. This might seem kind of dumb, especially if I really like the modded tone, but I think it would be a cool feature. Also there is a serious shortage of before-and-after clips for this mod and I'll certainly do a comparison once finished, a switch would make that really freaking easy.

I have a few questions to help me establish the feasibility first. I'm not an amp tech but I know just enough to be dangerous.

It looks like the circuit changes are simple and minor, just swapping caps and resistors. Are any of the affected components high-voltage? I ask this so I can find properly-rated relays if I choose to do this.

Second, I'll need a low-voltage power source to operate the relays. Would I be able to tap some juice from the tube heater circuit? Or is there a better option here?

And finally, I'm calling open-season on criticism for why this is a bad idea. Safety, component ratings, whatever. Like I said I'm not an amp tech and I don't have the intimate knowledge of these circuits that some of you guys have. I'm looking for technical criticism only, not the "That's dumb because you'll never want to go back to stock anyway" type.

It's a 2004 JCM2000 DSL 100-watt head if that has any significance. C46 upgrade and speaker jack fix have already been done.


----------



## Mr Boggie

Hi - im pretty new and green with this, but have a dsl50 from 2006 that I'd like to adjust the red channel.

I've read the posts, and opened up my dsl50. 

Would you have a photo of what yours looks like now? I am ready to clip, but its a touch confusing. The c12 on my pot board, is brown and thin like a hot dog, and its grouped with a few others in a line up. I believe its the 2nd from the left of the group. Any chance you'd be willing to teach this new kid a thing or two? This is on the control board, as its makes sense its linked to the gain pot on the red channel.


----------



## mkspriggs

So, so far i only did the c12 and jumped the r20 mod, but i must say for all modern metal heads this is a killer and needed mod for you, really opened it up looking forward to trying a few others


----------



## jinx1499

Is it possible to get links to parts or a parts list with item numbers from mouser on the first post? Just for consistency and thoroughness on the build?


----------



## TwinACStacks

jinx1499 said:


> Is it possible to get links to parts or a parts list with item numbers from mouser on the first post? Just for consistency and thoroughness on the build?



 The links are there you must have missed them. They are highlighted in Beige.

 TWIN


----------



## tjnugent

*Re: Joey Mods Completed...*



maltone said:


> I just finished doing the Joey Mods today with a friend who's an electrical engineer.
> 
> We did the following:
> 
> *FRONT BOARD*:
> 1M resistor from wiper to ground on VR3
> R20: removed and jumpered
> C10: replaced with .0022 uF 500v
> C12: replaced with 150pF @ 63v,
> 
> *MAIN BOARD*:
> C46: replaced with same value of 22pF @ 1000v
> C9: replaced with 1000pf
> C12: replaced with 1uF @ 63v (_while the original on-board cap read in at 100v_ —?)
> BIAS RESISTORS REPLACED:
> R67, R69 with 220K, 1/2 watt, metal film @ 1%
> R68, with 33K, 1/2 watt, metal film @ 1%
> R77: original stayed in amp because it wasn't a value of 10K as stated in our schematic, but 3.9k instead. We weren't sure if it was a good idea to replace this with a 10K value — and why would you? — Please someone explain.
> 
> OUTPUT TRANSFORMER: Installed a ClassicTone 40-18055
> DC FILTER CHOKE: Installed a ClassicTone 40-18058
> 
> *Comments and Afterthoughts*:
> After turning the amp on, we got that god awful HOWL, and then turned it off, realizing something was wrong. We found the online post on swapping W3 for W4. Sure enough, that solved the issue.
> 
> The plate voltage reading we got was 461, where as a few weeks ago with the stock Dagnall C7030, it was 466.
> 
> PERCEIVED TONAL CHANGES:
> I do notice that the Green clean and crunch channels are a bit clearer, have a tighter feel, less BOOMY, more articulation and definition. The flub that was there before we did the mods has been lessened.
> 
> I'm liking the GREEN channel. The RED channel is also more useable now, especially on LEAD 1 MODE at lower volume, and less gain. BUT we were dumbfounded when I turned the volume up on LEAD 1 — up to 4-5, and the gain up to 3. We got the most obnoxious and squealing high pitched feedback - whereas I didn't get this with my guitar before the mods.
> 
> UPDATE: Ignore this, the feedback is gone completely. I think it was some kind of acoustic induced feedback, where I was standing, how the speaker was angled, near the head, the room. Now the amp and speaker have been setup where I normally sit and play, and that squeal is gone.
> 
> Last night my brother in law and I AB'd his "stock" 2007 DSL100 against my "modded" 2008 DSL100, and mine definitely has more detail and seems clearer, more definition. But the tonal "feel" of the amps is still very similar, and still very Marshall.
> 
> We plugged in his Dean Z, exactly like this one: http://i5.photobucket.com/albums/y170/warmitag/My%20Gear/Armitage_Dean_BB_Z.jpg. It has a DiMarzio DP100 in the bridge. OMG. WOW. It sounded amazing. I've never heard a pickup with THAT much output. Using the volume control on the guitar cleaned it up, but still with some dirt, and it allowed us to set the volume and gain on the GREEN+CRUNCH channel much lower than through my Gretsch. I'm simply amazed at how good that combination sounds.
> 
> Much appreciated.



Do the Joey Mods pertain to the DSL40C at all, or is this a different beast altogether?

Thanks, 

TJ


----------



## 6StringMoFo

guitargoalie said:


> Aside from those videos buggs posted a long time ago, I have not seen one video or sound clip to show how the newly modified channels sound! Every so often I think about doing these, but I'd like to hear to get a basic idea first. I love my DSL, but sometimes I get picky and things are missing that I hear in other marshalls



+1 guys.

I've installed a choke, swapped out my Txs, pulled C12 from my frontboard and generally like my sound but I sometimes think about doing these mods.

Please, I would LOVE to hear some tone clips of the mods listed.


----------



## TwinACStacks

Alas I have long since sold/traded the DSL100 that started this thread. I've gone hybrid with the JMD1 and haven't looked back. It's DSL Models are actually better than a Real DSL with all the Joey Mods completed.

Sorry. JMHO

 TWIN


----------



## Grogshla

so they joey mod is just for tone? not for the efficiency and performance of the amp?


----------



## JPP

hi,
I think the mid control on a DSL50 adjusts the level of a fairly high mid frequency.

Is there a simple component change like using a different cap somewhere that will alter the mid control to a slightly lower mid frequency?

Also i like a middy sound and have the mid control turned up fully, is there something that will increase that control's level? 

I am not talking about modding the mid cut button like i have seen written in this thread.

hey thanks in advance.
john.


----------



## TwinACStacks

Grogshla said:


> so they joey mod is just for tone? not for the efficiency and performance of the amp?



 The Transformer exchange and choke will help with performance as well as the C46 mod not causing your amp to melt down or the Ground bypass mod on the output jacks causing you to burn up your OT.

But: *YES,* Basically it's ALL about tone...

 TWIN


----------



## SG-M-Marshall

Hello folks, I've done a few mods to this beast (listed below) all of which I'm really happy but I am wondering if there is a way to turn one of the reverb pots into a master reverb and have the other one to control the "deep switch" in a way like the newer DSL "resonance" pot. Or cutting some of the boom out in general when the switch is engaged, with it out the amp sounds really thin and the bass knob just adds a loose feel to the tone.

Mods Accomplished:
Input Board
C12 220pf (liked way better than clipping it)
R19 56k (jumped at first wasn't happy only had a 56k laying around)
VR3 1Meg wiper to ground 
Also changed LED "Green channel" to "Blue channel"

Tube Board
C46 2kv rating

Output 
Grounded 4&8 terminals

Tubes, MISC
KT77's (trying out 6CA7's later today, will be back with results)
NOS black plate Raytheon, silver plate RCA, copper post "D" getter GE. Current production Tung-Sol.
3H Mercury Mag Choke 
Any help on this will be greatly appreciated. :Cheers:
- Micah


----------



## SG-M-Marshall

Verdict on the 6ca7's: Slightly tighter bass than the KT77's but almost no mids. Top end is also really ice picky. I will be ordering KT77's again. Was worth a try but didn't suit my needs.  
-Micah


----------



## SG-M-Marshall

Ok nevermind my last post on the 6ca7's. After these last mods I really enjoy the sounds pouring out of the late 60's Ampeg V4 cab I have. The red channel is so tight with tons of warmth, INSANE amount of gain now. "blue" crunch channel is a hot rodded 800 tone hands down kills.....Downside clean channel is, well there is none, its a REALLY cranked clean tone reminded me of my old VT-22 (without the crazy volume). I will be reversing these mods to get a mix between what I have now and what the stock clean channel was. Which I loved. Can't win um all I guess haha. 


Mods Performed:
Input board
C22, C11, C10, R19, R20 all jumped
R36 two 6.8k metal resistors wired in series
C8 .0022uf mylar 100v cap
C12 220pf 500v ceramic cap
VR3 1Meg wiper to ground 
LED changed "Green channel" to "Blue channel"

Tube board
C46 2kv rated cap

Outboard
Grounded 4 and 8 terminals

Tubes and Misc
Mercury Mag Choke
6ca7 Power tubes
v1 CP Tung-Sol, v2 RCA Grey Plate, v3 Black Plate Raytheon, v4 GE copper posts


----------



## dango

After reading this thread for years (literally) - I finally took the plunge on some minor mods for my 98 DSL50.

- C12 removed on the pot board to cut some highs on the lead1/2 tones
- jumpered R12 to get more gain in the green crunch channel
- touched up some wonky solder joints that seemed to open up in a few areas

Granted I'm not testing at gig volumes just yet... but the amp has taken on a more ear-friendly / less ice-picky character - Marshall muscle and grind is still there, with distinctly different yet totally fun clean, crunch and lead 1/2 flavors. All tones are very usable/giggable -- the amp has never sounded this good. 

I'm still contemplating The C9/C12 mods on the main tube board to remove a trace amount of boominess in the green channel, but I'm not sure it's even worth the effort at this point given how nice things are sounding. 

HUGE THANKS to the folks out here that started and maintained this thread for the folks like me just foolish enough to give it a try!

Best,
dango


----------



## chuckharmonjr

Dango....you havent even stuck your toe in the water yet....seriously....do them all....you will be blown totally away


----------



## dango

Thanks Chuck! Actually I'm a little reluctant to do more for the following reasons:
1) takes alot of effort to pull the amp apart and put it back together!
2) the amp is sounding great as is at the moment
3) many of the mods on page 1 (on the pot board) seem focused on lead 1/2 - I'm less inclined to make those changes because I like what I'm hearing now

If I dive back in, my first order of business will likely be the c9/c12 mods on the main board, as that supposedly removes some of the minor flubbiness that I perceive on the green channel tones - did you find that these changes made a significant change in the amp?

Thanks again!
Dango


----------



## SG-M-Marshall

Dango, if anything do the NFB mod. Take a .0047 cap and put it in line after the R19 on the output board. Just did that and the C12 mod on the tube board along with the other mods posted above. I now have a really nice tight sound. To me there is nothing left to do other than stock up on black plate raytheons and get KT77's back in there. New pre amp line up as follows.
V1 NP Mullard CV4004(new favorite tube)
V2 NP Tung Sol 12ax7
V3 50's Black Plate Raytheon 12ax7
V4 50's Black Plate Raytheon 12ax7
Like I said it sounds really great now. After the new tubes, the NFB mod and C12(tb) I have my cleans back too. 
Good luck on the quest for tone buddy. 
-Peace.


----------



## SG-M-Marshall

Also no reason to be afraid I found removing the output board to be really easy. Take pics and have fun. Its worth the effort. I do crank my amp(MV5), however it still sounds great at low "practice" volumes. I will post some videos once I am able to meet up with my buddy who has a stock DSL50. So everyone can get a taste of what these mods can do.


----------



## rjohns1

I have begun to sort out these mods for the DSL40C. I will be tearing down mine and performng them Once I get this figured out, I will post the info.


----------



## johan.b

I didnt read through all the pages, so i appologise if this was covered

if you have an early jcm2000 dsl, that were built on the same pcb as the tsl line( you can tell by the fx loop jacks having a distinctly different look from the other jacks), you can easily make the loop footswitchable
all the electronics are allready there, just replace the reverb footswitch jack, wich is a mono break jack, with a stereo break jack and get yourself a two button footswitch.

why marshall didnt do this is beyond me. But i guess they needed to keep the features down to justify the tsl line..
j


----------



## Grogshla

is this mod easy to reverse? I bought a JCM2000 dsl with joey mod and aftermarket transformers. I want to turn it back to stock.


----------



## Ghostman

Grogshla said:


> is this mod easy to reverse? I bought a JCM2000 dsl with joey mod and aftermarket transformers. I want to turn it back to stock.



Yes, there's no permanent modifications done, just some parts replaced.


----------



## Grogshla

Ghostman said:


> Yes, there's no permanent modifications done, just some parts replaced.



Cheers mate. I appreciate your reply


----------



## chuckharmonjr

Actually...I have done the full magella....if you want the modded parts list I have it


----------



## chuckharmonjr

The stock schematics are out there and easily accessible. What I have is a list of change this resistor to this value, etc. This is a 33 page thread, so finding all that could be a bitch. I don't have a list of what the values were stock, but with my list and a schematic you could get back to stock very easily.


----------



## chuckharmonjr

Now...regarding certain mods. If the OT and PT have been swapped out for Mercury or Classictone....keep them. They are a helluva lot better than stock. Keep the choke....it does a lot better job than the BS resistor it replaced. Keep the output ground mod...it will save you a fried output section someday in the future. And the chincy underrated cap in the incoming power...I think its C11 but don't quote me....my notes and files are upstairs in the studio...it does absolutely nothing but expose your power tranny to a meltdown...leave it removed.


----------



## Grogshla

chuckharmonjr said:


> Now...regarding certain mods. If the OT and PT have been swapped out for Mercury or Classictone....keep them. They are a helluva lot better than stock. Keep the choke....it does a lot better job than the BS resistor it replaced. Keep the output ground mod...it will save you a fried output section someday in the future. And the chincy underrated cap in the incoming power...I think its C11 but don't quote me....my notes and files are upstairs in the studio...it does absolutely nothing but expose your power tranny to a meltdown...leave it removed.




Hi mate thanks for that.
I have no idea what exactly was done to the amp but the guy told me he did the joey mods and replaced both transformers and added a choke.

Comparing my stock amp and the modded one I notice the following differences.

Using them in exactly the same way (green crunch channel) with analoge stompboxes feeding the pre amp. I noticed that the modded amp has more of a loose roar, rich mids.
The original amp with this setup is Tight, scooped and focused (Which is what I want and need)

So If I can get it back to stock to get the same sound that is what I plan to do. Even if it means putting the Original Transformers in there. I even have a spare stock PCB that I can put in there if that is easier.

I plan to keep the output jack mod on it so i can run 2 boxes if needed. But apart from that everything must go back to normal.


----------



## Grogshla

chuckharmonjr said:


> The stock schematics are out there and easily accessible. What I have is a list of change this resistor to this value, etc. This is a 33 page thread, so finding all that could be a bitch. I don't have a list of what the values were stock, but with my list and a schematic you could get back to stock very easily.




thanks mate yes i would love a copy of this. Never heard of C11 causing a meltdown. I would assume I have the C11 still there in my rebuilt stock JCM2000dsl and never had a problem so I will probably change this back to stock also...unless other people can offer some advice.


----------



## sneakyybstrd

Do these mods apply to the newer dsl100h...partcularly the output speaker ground mod and c12 mod....


----------



## Micky

No. It states this somewhere in the thread...


----------



## Grogshla

chuckharmonjr said:


> Actually...I have done the full magella....if you want the modded parts list I have it




Hi, Yes I would greatly appreciate this list of mods so I can reverse it all.
Also what transformers do the stock marshalls use? and what stock preamp tubes do they use?


----------



## dslman

Is it necessary to address C46 on the DSL 50 , and how will clipping it out effect the amp ? there is no tube in the socket closest to it. Mine has the orange round cap that reads 220 AQC . Thankfully I have the correct value 5k6 grid blockers and the bias resistors are correct,"1 exception R77 appears to be 39k instead of 10K. Looks like a lot of work to change out C46 . Any comments is appreciated. Thanks


----------



## Grogshla

still waiting for the full parts list.

Who can tell me what the stock transformers used in the amp are called? I want to replace my aftermarket ones and remove the aftermarket choke that was put in.


----------



## recto-robbie

Hey grogshla, if you don't mind me asking, what brand of upgraded transformers do you have in that dsl50?


----------



## jazzmag

Anyone know of any alternatives to the MM transformers? They pricey !


----------



## mickeydg5

Some go Lydian or Hammond but a lot like ClassicTone.


----------



## mkspriggs

So kinda off topic in a sense. But how do the bigger modders like say Mike Fortin and others ive seen turn these into incredible gain monsters? Ive read most of this thread and done the few where you either delete the circuit or jump it etc also swapped out my ot for mercury and installed the choke of theirs aswell which all was awesome. But I only play high gain metal and would love to not have to worry about boost pedals, i like to keep it simple. I know with Fortin he does wild mods like adding 2 or more power tubes and more preamp tubes, I saw one where he had roughly 8 Power tubes mixed and mixed tubes at that something like 2 el34, 2 6550, 2 6l6 and 2 of something else it was nuts lol. But im sure thats above most of our levels lol. 

Also im sure some of you have read my other post where I had bought a randall satan to have more gain but it was lacking the power that marshall is so good at. So basically id like to get the gain of the satan and keep the power of the marshall lol. I know im asking for alot lol


----------



## diesect20022000

mkspriggs said:


> So kinda off topic in a sense. But how do the bigger modders like say Mike Fortin and others ive seen turn these into incredible gain monsters? Ive read most of this thread and done the few where you either delete the circuit or jump it etc also swapped out my ot for mercury and installed the choke of theirs aswell which all was awesome. But I only play high gain metal and would love to not have to worry about boost pedals, i like to keep it simple. I know with Fortin he does wild mods like adding 2 or more power tubes and more preamp tubes, I saw one where he had roughly 8 Power tubes mixed and mixed tubes at that something like 2 el34, 2 6550, 2 6l6 and 2 of something else it was nuts lol. But im sure thats above most of our levels lol.
> 
> Also im sure some of you have read my other post where I had bought a randall satan to have more gain but it was lacking the power that marshall is so good at. So basically id like to get the gain of the satan and keep the power of the marshall lol. I know im asking for alot lol


Framus.


----------



## Grogshla

recto-robbie said:


> Hey grogshla, if you don't mind me asking, what brand of upgraded transformers do you have in that dsl50?



its a JCM2000 DSL100w head. I have Classic Tone transformers and a choke.


----------



## maltone

*Re: Front Board C8 & C12*

Did the full Joey Mods well over a year ago, but never changed C8. Originally lowered FRONT BOARD C12 to 150pF - later removing it. Put in 150pF again tonight and like the RED channel much better. 

Front Board C8 was changed to .0015uf tonight. MUCH better bass. Definitely clearer, less boomy, more detail. I dig it. 

One question though, those values from the original Joey Mods list for FRONT BOARD C8, were those like the JMP or JCM 800 values? 
.0022uF TO .0015uF

— I'm just curious.

Thanks.


----------



## AndyK11

xjbear said:


> turns out that you can turn the mid scoop switch into a mid boost very easily, replace R36 (68k)with a 27k resistor, replace R35 with a 5.6K resistor, switch (pushed In) your at stock DSL settings (33k total), switch out you have a mid boost (5.6k), Cake! or just put the pot in there and sweep it whatever



This is a cool idea!! How much mid boost would there be, and what frequencies are now being boosted with the tone shift button?


----------



## therealjoeblow

Does anyone know who makes the multi-conductor board connectors for these amps (model no/brand)? IE CON3/CON10, the 6-pin multi connector on the front and rear board?

thanks
TRJB


----------



## G the wildman

Hi guys,

Do I need to discharge the stored voltage in my amp to check the bias. I suppose the answer is no as I need power on. But I am more thinking about removing the head can I get a shock whilst doing that?

What precautions should I take.

G


----------



## G the wildman

Oops it is a DSL40c


----------



## mickeydg5

Check out this thread and ask there. It is all about the new series DSL40C.

http://www.marshallforum.com/showthread.php?t=53780


----------



## therealjoeblow

therealjoeblow said:


> Does anyone know who makes the multi-conductor board connectors for these amps (model no/brand)? IE CON3/CON10, the 6-pin multi connector on the front and rear board?
> 
> thanks
> TRJB



Nevermind, answering my own question here. ALL of the small white board connectors on the JCM 2000, Vintage Modern, MG series and most other modern amps are "JST EH" series connectors, available from Digikey and various eBay sellers.

Cheers
TRJB


----------



## Pandemic

Hi yall! I am about to pick up one of these bad boys tomorrow. I used to have a jet city 100h that i modded but its flimsey and not that roadworthy, so i found a cheap Dsl 100. I am hoping the PCB versions checks out so i can mod this one too... (I just like tinkering with stuff) 

But if the pcb´s dont match am i then resorted to not being able to do the mods or should i just try and match up the differences in the schematics and find where the parts are on the other drawing ?

Cheers from Denmark


----------



## Pandemic

So i for my DSL and I do like the bastard but it definitely needs some mods  but when I cracked it open the revisions of the boards don't seem to match any of those listed in this thread. The main board is a jcm2 60-00 ISS 6 and the other 2 are the ones are also different front isjcm2 60-00 ISS 3 and the loop/output board jcm2 62-00 ISS 2... How do I go about figuring what's what on the boards ?


----------



## Micky

Pandemic said:


> So i for my DSL and I do like the bastard but it definitely needs some mods  but when I cracked it open the revisions of the boards don't seem to match any of those listed in this thread. The main board is a jcm2 60-00 ISS 6 and the other 2 are the ones are also different front isjcm2 60-00 ISS 3 and the loop/output board jcm2 62-00 ISS 2... How do I go about figuring what's what on the boards ?



So are those the boards in your DSL? When was your DSL manufactured?


----------



## Pandemic

As far as I can tell by the serial number on the back 2006... I have some pictures of the boards I can post in case I'm reading the bloody thing wrong


----------



## Pandemic

Serial Nr. M-2006-16-0707-A


----------



## chuckharmonjr

yep..I'd make that as a 2006 model


----------



## rockgod212

well im working on my amp again, I made a lot of improvements with chassis mounted power sockets, no more high voltage heat issues on the main board. now, I had already modded my bias to a 1 pot circuit like the old school marshalls, so now im in the process of going a step further by removing the bias cap's and building a bias cap board like the older marshalls have for ease of biasing and easy access to change parts if need be, plus the bias ground will be on chassis and not the main board. I have a few odd ball questions though,

1. why did marshall use 47uf bias caps?
2. since im going to a 2 bias cap circuit, what value cap would be best? I ordered 10uf, 22uf, and 47uf@160v. im thinking split the difference and use the 22uf@160v with a 10k to 15k between caps and a 10k to 50k bias pot.
3. is there any other way to tap my AC bias voltage other than the 2- 22vac taps to bias recto's?

just curious.


----------



## RickyLee

rockgod212 said:


> well im working on my amp again, I made a lot of improvements with chassis mounted power sockets, no more high voltage heat issues on the main board. now, I had already modded my bias to a 1 pot circuit like the old school marshalls, so now im in the process of going a step further by removing the bias cap's and building a bias cap board like the older marshalls have for ease of biasing and easy access to change parts if need be, plus the bias ground will be on chassis and not the main board. I have a few odd ball questions though,
> 
> 1. why did marshall use 47uf bias caps?
> 2. since im going to a 2 bias cap circuit, what value cap would be best? I ordered 10uf, 22uf, and 47uf@160v. im thinking split the difference and use the 22uf@160v with a 10k to 15k between caps and a 10k to 50k bias pot.
> 3. is there any other way to tap my AC bias voltage other than the 2- 22vac taps to bias recto's?
> 
> just curious.



Hopefully you see this post. I am thinking you should start a thread in the Workbench as it will be seen.

That is quite cool removing the power tube sockets from the main board. I have considered it but just can't get myself to do it LOL. My '98 DSL100 is actually all stock and I am still just blown away at the difference in tone between my '05 DSL100 when it was stock as well as my '99 TSL100 while it was stock. I have no bias drift issues on this '98 DSL100, so the superior tone might be partly due to the main board is not acting up in any way. Actually, I did upgrade all the bias supply components and swapped the power tube grid resistors from 220K to 5.6K.

Actually, I just got done installing a Classic Tone 3H choke. So she is not stock anymore. I can't say I am hearing a clear difference, but it is somewhat tighter on the low end response. Maybe a slight less noise. The noise/hum was what I tried to concentrate on as I had the amp cranked to max volume with guitar volume OFF with the 270R resistor. Then I soldered in the choke immediately (already had it mounted) and then turned on amp with the new choke for a comparison. I then played Lead 1 with Volume around 6 and Gain at 6 and OMG! This amp is what the DSL is supposed to sound like no doubt. Nothing wrong with having the front control board 470pF C12 in this amp. I was playing AIC Would?. The tone was there in spades.

What I don't like with the choke upgrade is the higher B+ voltage. The resistor drops 8V while this choke only drops under 3V. But then I need to remember there will be major difference under load with the choke inductor. Pros and cons.

I was also going to reduce the main board C12 first gain stage cathode bypass cap a bit, or might put a switch to give me options of .47uF (or maybe .68uF), 1uF and stock 4.7uF. But I really do not think this amp needs it. Lead 1 is the highlight of this amp big time and the stars were aligned somehow on component values when this amp left the factory. If most DSL's and TSL's sounded like this one, there probably would not have been this mod thread to begin with.



As for your bias circuit, I am sure you got it sorted now. Did you stay with the stock voltage feed? You could always tap off the HT leg like many other amps do for the bias supply voltage feed.


----------



## RickyLee

I rushed a quick audio clip of this '98 DSL100. Clip blows but it was all I could do to make noise for a few short minutes LOL. It starts on Crunch mode then goes to Lead 1 at 11 seconds. Back to Crunch at 24 seconds with neck single coil then stays on Lead 1 at 37 seconds rest of the way. Shows how close Green channel and Red channel are on this amp. My '05 DSL100 was nowhere near this as its Red channel had very sharp highs, almost ice pickey. And that amp had a bad overall fizzy tonal texture.

This recording was just my little Tascam DR-05. The lows got a bit distorted on the mic. Clip shows just a touch of the tight midrange defintion and grind on the Lead 1 mode that you would hear in person.

This amp loves the cheap Svetlana EL34's. They sound very similar to Wing C EL34's except they have a much tighter and focused low end in this amp.

http://www.soundclick.com/player/single_player.cfm?songid=13341888&q=hi


----------



## rockgod212

sounds killer


----------



## HOT TUBES 70

Question ??


When doing These mods to the DSL amps , is these any of these Cap or Resistor mods that would be cool to put on switches on the front or rear panels ?
Or are these mods just best to do them and leave em well enough alone ?


----------



## Traveller

Guys, slightly offtopic, but I suppose here I can find most answers for my question - how do You find PCB Quality in DSLs? I am aware of bias drifting issue, but I heard that PCB in DSL is generally prone to bending (too thin I suppose?), what can cause reliability problems. Is it true? Was there any changes in PCB thickness among the production years? I am currently looking for DSL50 and I wonder which 'era' is concidered as a "most consistent". I am based in Europe, so I think it would be hard for me to find one with Drakes, so I plan to stick with 2003-2012 models, to find something that shouldn't have bias drift problems, and still be made-in-UK, but this PCB still concerns me...

Any help with choosing Duper-Super-Lead for me will be gratefully welcomed, both here and on my topic: http://www.marshallforum.com/index.php?threads/dsl50-issues-and-year-ly-production-quality.89708/


----------



## RickyLee

HOT TUBES 70 said:


> Question ??
> 
> 
> When doing These mods to the DSL amps , is these any of these Cap or Resistor mods that would be cool to put on switches on the front or rear panels ?
> Or are these mods just best to do them and leave em well enough alone ?



This second DSL100 I have is basically stock. But I did add a choke to it just a few weeks ago. I was considering doing something as you mentioned for the first gain stage. I might make that first gain stage cathode bypass cap switchable between .47uF or .68uF/1uF/4.7uF. Stock it is 4.7uF. 

A switchable bright cap on the Red channel Gain pot is another idea I am considering.


----------



## AndyK11

I just read EVERY post in this entire 50 page thread! I'll be dreaming of caps and resistors coming to kill me in the form of a kangaroo!

I just want a DSL that sounds more brown, more like a modded Plexi or Friedman Brown Eye on the red channel, to get better early Van Halen tones. No modern, scooped high-gain metal for me! I think there are several red channel mods that would make sense for me to do:

C12 (tube board) reduced to lower low end early on in the signal path
C12 (front board) reduced to tame brightness with gain at 12:00 or below
NFB cap addition to tighten things up
Anything else?

You know how when playing on the green channel, and you hit the footswitch to go to red, and you notice a thinner, brighter, almost shrill tone compared to the green crunch? Will the above mods help cure that problem?

Thanks all!


----------



## Grogshla

I have the Joey mods done to my jcm2000 dsl 100w head and it is constantly losing volume and causing the 2 inner power tubes to glow white hot. Any ideas on what could be causing this. I have serviced the amp 3 times and it always has the same issue with the same 2 tubes. I have tried marshall tubes, jj tubes and now on tungsols which just did the same thing. My amp also has 2x classic tone transformers and a choke


----------



## cudbucket

So much great info here. I have my DSL on the bench right now and have done the speaker jack mod as well as replacing C46 with a 1kV cap. Tomorrow, C12 comes out. Can anyone help me with spec'ing the 7 "big" caps on the tube board. This is what I'm planning to order from Mouser.

330uF 315v: http://www.mouser.com/Search/Produc...RDvirtualkey64700000virtualkey647-UVZ2F331MRD
100uF 350v: http://www.mouser.com/Search/Produc...HDvirtualkey64700000virtualkey647-UCY2V101MHD
22pF 450v: http://www.mouser.com/Search/Produc...Svirtualkey66720000virtualkey667-EEU-EE2W220S

Also, I want to get turrets for the Choke install. What size mounting hole do I need when ordering the turrets? Thanks so much!

Dave


----------



## RickyLee

AndyK11 said:


> I just read EVERY post in this entire 50 page thread! I'll be dreaming of caps and resistors coming to kill me in the form of a kangaroo!
> 
> I just want a DSL that sounds more brown, more like a modded Plexi or Friedman Brown Eye on the red channel, to get better early Van Halen tones. No modern, scooped high-gain metal for me! I think there are several red channel mods that would make sense for me to do:
> 
> C12 (tube board) reduced to lower low end early on in the signal path
> C12 (front board) reduced to tame brightness with gain at 12:00 or below
> NFB cap addition to tighten things up
> Anything else?
> 
> You know how when playing on the green channel, and you hit the footswitch to go to red, and you notice a thinner, brighter, almost shrill tone compared to the green crunch? Will the above mods help cure that problem?
> 
> Thanks all!



I guess the disparity between many DSL's that left the factory not created equal continues. And now I see there is no magic in the year of '98. My first DSL100 was from '04. I did the mods you mentioned above and then some. When it was stock, it seemed to be very much like you describe. Mine had this fizz in the upper mids that was hard on the ears and just could not be dialed out unless I killed the top end with very low treble settings, mainly on the Red channel I should add. But the entire amp did have an unpleasant plastic sterile tone about it until it was cranked to such a high level that would drown out an entire band and piss off bar managers for sure. 

Then I got a second stock DSL100 from '98 that was at the opposite end of the spectrum. The Red channel was slightly more midrangey but in a very good way. Sweet crunch and very good tone at lower volume settings. I still have not touched this '98 for mods except for installing a choke. There seems to be many more very good ones and bad ones out there with inferior tone and heat/bias issues than ones that are just in the middle of the road for tone. This amp was obviously produced more than any other Marshall that I know of, so that has to play into the recipe with the ingredients just having a slight variation in the final tone outcome.

I would think your mods should work out for you. Did you try them yet?


----------



## RickyLee

Grogshla said:


> I have the Joey mods done to my jcm2000 dsl 100w head and it is constantly losing volume and causing the 2 inner power tubes to glow white hot. Any ideas on what could be causing this. I have serviced the amp 3 times and it always has the same issue with the same 2 tubes. I have tried marshall tubes, jj tubes and now on tungsols which just did the same thing. My amp also has 2x classic tone transformers and a choke



Has the problem with the tubes getting too hot flared up when the techs were servicing the amp? Was there a problem they said they found and fixed?


----------



## RickyLee

cudbucket said:


> So much great info here. I have my DSL on the bench right now and have done the speaker jack mod as well as replacing C46 with a 1kV cap. Tomorrow, C12 comes out. Can anyone help me with spec'ing the 7 "big" caps on the tube board. This is what I'm planning to order from Mouser.
> 
> 330uF 315v: http://www.mouser.com/Search/Produc...RDvirtualkey64700000virtualkey647-UVZ2F331MRD
> 100uF 350v: http://www.mouser.com/Search/Produc...HDvirtualkey64700000virtualkey647-UCY2V101MHD
> 22pF 450v: http://www.mouser.com/Search/Produc...Svirtualkey66720000virtualkey667-EEU-EE2W220S
> 
> Also, I want to get turrets for the Choke install. What size mounting hole do I need when ordering the turrets? Thanks so much!
> 
> Dave



Did you get your caps ordered yet?

I think this person sells the recap kits for the DSL100/50 and TSL100/122.

http://www.lydian.ca/Parts/Pages/Marshall_DSL_Transformers.html


----------



## cudbucket

Hey Ricky,

Yes, I got them ordered and am in the process of installing. Thanks for the info though!

Dave


----------



## mikerevis

Question... Removing C46 as a precaution... Ok. Just cut it out or jumper? Thank you!


----------



## RickyLee

mikerevis said:


> Question... Removing C46 as a precaution... Ok. Just cut it out or jumper? Thank you!



Are you referring to C46 that is on the main board on the V8 socket?

If so, DO NOT JUMPER THAT CAP! That cap is across pins 3 and 4 of that EL34 socket. That cap can just be snipped off. Or if you want to keep it, upgrade it with a 1000 volt rated and use the same value.


----------



## mikerevis

RickyLee said:


> Are you referring to C46 that is on the main board on the V8 socket?
> 
> If so, DO NOT JUMPER THAT CAP! That cap is across pins 3 and 4 of that EL34 socket. That cap can just be snipped off. Or if you want to keep it, upgrade it with a 1000 volt rated and use the same value.


I was referring to C46 the cap that can potentially take out the ot. I believe you answered my question... Snippy snip snip! Thank you!


----------



## mikerevis

Ok Guys. She's fired up. Now, the first two tubes (DSL 50 head counting from input to power) the first two preamp tubes light up normally, then volume fades and the "Lights" go out on them. The first two only... Swapped for a known good pair of 12ax7's, and... Same thing. Help!!!


----------



## RickyLee

mikerevis said:


> Ok Guys. She's fired up. Now, the first two tubes (DSL 50 head counting from input to power) the first two preamp tubes light up normally, then volume fades and the "Lights" go out on them. The first two only... Swapped for a known good pair of 12ax7's, and... Same thing. Help!!!



You need to check heater voltage going to those two sockets. The heaters are AC for the EL34's and also V3 and V4. Then there is a run from the AC to a bridge rectifier that converts to DC for V1 and V2. Start with that as your first check. My 2005 TSL100 has a huge 6 amp bridge rectifier on its PCB. I do not know if Marshall upgraded those at some point, but that 6A on my PCB is way beyond what is needed.


----------



## Cascadem

Hello, new to the forum but have been following it for a long time from the outside world lol.
I have many questions for this thread, for now:
I have jumpered R12 on the pot board, love it, does jumpering R20 do the same for the red channel as R12 did for the green?

Seems like the green channel has slightly more output to the poweramp than the red at this point after jumpering R12. I did adjust the C8 4n7 cap in the green channel to .0022 and now both channels are very similar in eq but just trying to give the Red Channel a kick in the ass like I did the Green.


----------



## tripptripp

Hello All, first post here. In troubleshooting my jcm 2000 DSL 50 (made in 2000), I came across this awesome thread and have been doing some of the mods. In the process I'd like to do the preventative maintenance including the grid blockers, but I'm not sure which resistors are the grid blockers on my board. I haven't seem anyone mention my version of the main board or I could have missed it in the 50 pages that make up this massive thread. It's a jcm2-60-00 iss5. Any help will be greatly appreciated!


----------



## RickyLee

Cascadem said:


> Hello, new to the forum but have been following it for a long time from the outside world lol.
> I have many questions for this thread, for now:
> I have jumpered R12 on the pot board, love it, does jumpering R20 do the same for the red channel as R12 did for the green?
> 
> Seems like the green channel has slightly more output to the poweramp than the red at this point after jumpering R12. I did adjust the C8 4n7 cap in the green channel to .0022 and now both channels are very similar in eq but just trying to give the Red Channel a kick in the ass like I did the Green.



Jumpering R20 would give the Red channel a bit more high end and a bit more gain as well. 

But to get the same effect as what you did on the Crunch channel, you would want to jumper R19. But that will increase gain in that channel quite a bit and then make Lead2 possibly usuless. It might make Lead1 too gainy to where you then dial back the Gain control to compensate, which will then add more high end (unless you already removed C12?).


----------



## RickyLee

tripptripp said:


> Hello All, first post here. In troubleshooting my jcm 2000 DSL 50 (made in 2000), I came across this awesome thread and have been doing some of the mods. In the process I'd like to do the preventative maintenance including the grid blockers, but I'm not sure which resistors are the grid blockers on my board. I haven't seem anyone mention my version of the main board or I could have missed it in the 50 pages that make up this massive thread. It's a jcm2-60-00 iss5. Any help will be greatly appreciated!



I was only able to find the DSL50 2003 main board scheme. It shows the control grid resistors as R66 and R70 and it shows them as the proper 5.6K value. I am sure those resistor numbers should be the same on your main board.

Have you verified your board has the 220K there?


----------



## tripptripp

RickyLee said:


> I was only able to find the DSL50 2003 main board scheme. It shows the control grid resistors as R66 and R70 and it shows them as the proper 5.6K value. I am sure those resistor numbers should be the same on your main board.
> 
> Have you verified your board has the 220K there?




Hey thanks RL, I didn't get a notification of your reply. I did verify they are 220K. I went ahead and swapped R66/R70 for 5k6ers and everything appears to be fine.


----------



## Cascadem

RickyLee said:


> Jumpering R20 would give the Red channel a bit more high end and a bit more gain as well.
> 
> But to get the same effect as what you did on the Crunch channel, you would want to jumper R19. But that will increase gain in that channel quite a bit and then make Lead2 possibly usuless. It might make Lead1 too gainy to where you then dial back the Gain control to compensate, which will then add more high end (unless you already removed C12?).


No havent removed c12 on the front board yet.


----------



## Cascadem

Ricky Lee, lets talk about how I voiced my channel 1 first to better understand what I seem to like out of the amp. So, I changed C8 on the front board to .001, removed R7 and jumpered it, removed and jumpered R12. Now this is all on the just the front board. Now to the main board, I changed R12 from 68K to 47K, changed R14 from 1.8k to 1.5k as well as R15 from 1.8k to 1.5k carbon comp resistors used for all changes. I changed all of the amps coupling caps and tone stack caps to Mallory 150 polyester type. The tone stack on the front board has been changed to: C19 remove and jumper, R35 changed to 15K, R36 changed to 19K, C22 has been removed and jumpered, this seemed to be the closest to making my tone stack into a 2204 tone stack without changing pots and yeilded the tone shift switch into a mid boost when disengaged rather than a scoop. Nearly stock when engaged.
I THINK at this point...I want to tame the high end of the amp in the lead 1 and lead 2 channel. The tone of channel 1 is good. I am using speakers that let alot of high end through and bright pickupsin my les paul so I dont want to tame the high end of the entire amp per say so when I run darker speakers and a thicker darker pup (much like a ducan custom/JB/59custom hybrid/ custom custom) I still have the abiltiy to bring the treble and presence knobs up a tad. As far as bass/low end...I have converted channel 1 reverb into a master reverb control and am now using the channel two reverb as a resonance knob that can cut below stock with deep switch out or...boost up to deep switch in. Kinda makes the deep switch useless unless, you want the full effect of the stock deep switch all at once and fast, no dialing in needed if you use the deep switch...if thays what one wants.
But lets just focus on what I have done to the preamp and keeping the tone stack changes and cathode and grid value changes in consideration.
I have been considering trying out removing and jumpering R34 and R37 on the front board as the JCM 800 2204 didnt have them in the circuit at all.
Walk me through your thoughts lol!


----------



## Cascadem

And I should mention that the amp front board is JCM2-61-00 and the main tube board seems to be JCM2-60-00 (labeled buy Marshall as such, however, when I go through the board it appears the component values are closer to the DSL50-60-02).
Amp is a DSL 50 made in 2003. Running original Marshall Preamp tubes (whatever they actually are) and Winged C power amp tubes. I HAVE been considering trying the JJs KT77 outputs and their standard ECC83 preamps. I have always thought of JJ PREAMP tubes to be a tad on the darker side compared to alotof others out there. That might or might not even tame the high end of the amp. I SHOULD SAY, I am not displeased with the amps amount of high end, however am running my pres on 4, treb on 5, bass on 3, and well my res knob is set about to stock dsl with deep sw out. Mid well, its kind of funny cause I tend to run the boost on and then bring the knob back to around 3....as crazy as that sounds.


----------



## Cascadem

.


----------



## guitardude57

jcmjmp said:


> The mods listed by TwinAC above pretty much covers everything but these are more mods that I've been asked for on a regular basis.
> 
> 1) Footswitchable channel modes:
> http://www.marshallforum.com/workbench/8904-marshall-dsl-50-100-clean-crunch-footswitch-last.html
> 2) Deep switch
> 3) Mid cut




I have a DSL 40C here, with the board DSL 100-60-00 Series one. Has the single large board. Have you a schemo and mod list for this creature? All my schemos for the DSL stuff does not really match up.


----------



## 6StringMoFo

Someone has the resources to translate?

My Main board is a JCM2-60-00 ISS20
My front board is a JCM2-61-00 ISS345

Looking to translate this components.
-----------------------------------------------------------
JCM2 60-02 iss5 (Tube) AND JCM2 61-00 iss1 (Front)


Front Board: 

NOTE: THESE MODS AFFECT THE RED LEAD 2 MODE ONLY (removing C12 will also darken Lead 1)

1M Resistor from Wiper to Ground on Vr3 **** *(DONE)*
C12 Lower to 150pf or REMOVE (I removed it) *(DONE)*
C10 replace with .0022 uf
R20 Remove and *JUMPER*

**** These can be bridged on the other side of the Board. Find the 4 Pins that are the Actual Pot terminals, (Not the Two Board mounting pins), follow the Traces. The inner one that has R19 on it is the WIPER, the outside one that connects to Con 5 pin 2 is the Ground. ( Using your meter set to continuity works well here) Solder your 1M across these 2 pins leaving the legs long, then bend flat to board using a piece of electrical tape attached to the board to insulate the leads from accidentally shorting out to any other exposed solder connections. Electrical splicing tape works quite well here as it adheres to the board better than vinyl electric tape.


Mainboard: 

NOTE: THESE MODS AFFECT ALL CHANNELS/MODES

C9 replace with 1000pf (.001uf) 500V
C12 replace with 1uf 63V
-----------------------------------------------------------


----------



## 6StringMoFo

Aye, Marshall sent me all their schematics hah. I'm doing the mods now.


----------



## johan.b

Another thing you can do is increase r21 (referring to old schematics) on the pot board to 470k-1M. It's originally 150k and it cuts low end in od1 to keep things focused. But it's too much and makes the bass eq knob ineffective and the channel thin compared to green channel. Increasing it restores the low end and makes the bass knob effective again. You can cut it out all together, but bass will be very compressed and fuzzy. .some might like that though. ..choosing value is a balancing act and some compromise will have to be accepted, but it's about restoring the low end that was lost where as the c12 mod is compensating by cutting the high end too..i preferred it this way, but someone else will have to try and say what they think. 
j


----------



## Stamminen

Quick question guys, I'm planning on doing the C12 mod on my 2003 DSL50 once I decide to open her up. Finding the red channel to be to brittle like everyone else.

Instead of clipping it completely I'd like to replace it with a different value. I don't know much about caps, but is this what I should be buying? Link is to an eBay seller. If I need a different kind of cap let me know.

I'm planning on possibly trying a 68pF, 100pF or 150pF

Thanks!

http://www.ebay.com/itm/322359203629?_trksid=p2060353.m1438.l2649&var=511281869560&ssPageName=STRK:MEBIDX:IT


----------



## dslman

Stamminen said:


> Quick question guys, I'm planning on doing the C12 mod on my 2003 DSL50 once I decide to open her up. Finding the red channel to be to brittle like everyone else.
> 
> Instead of clipping it completely I'd like to replace it with a different value. I don't know much about caps, but is this what I should be buying? Link is to an eBay seller. If I need a different kind of cap let me know.
> 
> I'm planning on possibly trying a 68pF, 100pF or 150pF
> 
> Thanks!
> 
> http://www.ebay.com/itm/322359203629?_trksid=p2060353.m1438.l2649&var=511281869560&ssPageName=STRK:MEBIDX:IT


Sorry you didn't get an answer, I don't get to this thread much any more, and looks like I'm not the only one.
The answer to your question is yes. I went with a 331pf cap in mine. Tried several values as well as clipping it--which sucked the sting and gain out of the amp.
Mine is a DSL50 also.


----------



## dslman

Here's a added safety touch for the ohm selector switch on the 2K DSLs,
I saw a video where the tech. had a problem with the switch , since it is only connected by the solder pins.
After he repaired the amp he put some hot glue around the outside of the switch and the chassis, for more stability. This may be splitting hairs, but I did the same.
Should be a bit more sturdy when using the switch.












20170430_111751_1493577492614



__ dslman
__ Apr 30, 2017


----------



## Razvan S.

Hello

I have been lurking for some time on this thread. I would like to thank Joey for his work, it is priceless!

I want to add here, the 60-00 version transcription from the thread version with the Notation changes.
Note the modifications in bold with yellow.
PLEASE correct me if I am wrong, but I have already rechecked and everything looks right(LE: rechecked now, I can assure that everything is OK  ):


*I did a simple comparison, and here is transcription for the 100W 60-00 version (from the one in the thread, the 60-02 version), for the Tube (main) board.*


*The FRONT board, is the same. So no changes there.*


*I want to mention that I did no mods to my amp, and I honestly think it sounds great as is, even at low volumes; however I see that on the 60-00 version, there are some changes and this would suggest why it is sounding better “stock”. The 10K being stock (recommended 5k6 by the guys here) instead of the 220K stock on the schematic. Also, C46 is missing entirely.
Maybe in the future I will try out some stuff, and jumper everything.
I have a 2009 Model.
In brackets I have mentioned with "was'' the notation which is for the 60-02 version, and in the front for the 60-00 version.*

Frontboard(no changes)

NOTE: THESE MODS AFFECT THE RED LEAD 2 MODE ONLY (removing C12 will also darken Lead 1)

1M Resistor from Wiper to Ground on Vr3 ****
C12 Lower to 150pf or REMOVE (I removed it)
C10 replace with .0022 uf
R20 Remove and *JUMPER*

**** These can be bridged on the other side of the Board. Find the 4 Pins that are the Actual Pot terminals, (Not the Two Board mounting pins), follow the Traces. The inner one that has R19 on it is the WIPER, the outside one that connects to Con 5 pin 2 is the Ground. ( Using your meter set to continuity works well here) Solder your 1M across these 2 pins leaving the legs long, then bend flat to board using a piece of electrical tape attached to the board to insulate the leads from accidentally shorting out to any other exposed solder connections. Electrical splicing tape works quite well here as it adheres to the board better than vinyl electric tape.


Mainboard:

NOTE: THESE MODS AFFECT ALL CHANNELS/MODES for 60-00 version:

*C4 (was C9)* replace with 1000pf (.001uf) 500V

*C7 (was C12)* replace with 1uf 63V


Now if You find that the overall texture of the amp is, or has become too dark:

Mainboard:

Replace *R18 (was R30)* (470k)with 68k to 220k resistor this will Decrease the Fizziness and the OVERALL GAIN as well and also brighten the Amp. I personally Piggybacked, (using a pair of test leads), a range of resistors across the Legs of *R18 (was R30)* from 82k to 1M and decided I liked 1M the Best. This brought the Value of *R18 (was R30)* to 320k. I then soldered it in place across the legs of *R18 (was R30).* This way it is easily changed if I decide on a different value without pulling the PIA Mainboard!!! This particular Mod is pretty much season to taste. One of the Techs or Myself can figure out what value you need for "Piggybacking", or you can try and figure it out yourself:

R1XR2 Divided By R1+R2= the Total resistance of Both Resistors combined. Use the Value of *R18 (was R30)* (470)k for Resistor1 and the resistor You want to try as the value for Rresistor2. (Try: 82k, 120k, 220k, 330k, 470k and 1m)

Also if You find that the Green CRUNCH Mode is too boomy especially with the deep switch engaged:

*Frontboard(NO changes here for notations, because they are the same!)*

C8 replace with .001uf to .0022uf (I used .0015uf)

Here's a link: http://www.mouser.com/ProductDetail...EpiMZZMsh%2b1woXyUXjyBw8LYChpgf%2bpPFAhHPmAM=


THESE ARE THE EXTENT OF THE ORIGINAL MODS.


Now THIS is the "while You are in there" section of the Mods that SHOULD be performed.

*C46* if You have one *(this does not exist in the 60-00 Version!!).* This is an underspeced Cap that apparently is to prevent parasitic oscillations. It can short out and Take out the board it's on, as well as your OT. Either CUT it OUT or replace it with a +1000V version of the same value (22pf). I say "apparently" because I have heard nothing about anyone experiencing oscillations after removing this cap completely.

Change out the Grid Blockers on the Mainboard. Most versions have 220K in place, replace with a more normal "Marshall" value 5k6 resistor. I'm of the understanding Alan Bradley Carbon Comps are suited quite well for this, I used regular +/- 5% carbon films from Radio Shack that I had on hand.

The locations for these are: *R55 (was R7), R70 (was R10), R58 (was R66), R62 (was R70)*

*(ironically, mine were all 10K (??weird) on the 60-00 version, which is close to 5k6 and I wouldn’t bother changing these, if you have the same on the 60-00 version)*

Also because of frequent run-away biasing problems That appear to be temperature related, Upgrade the Bias resistors. I suggest a more temperature-stable precision metal film 1/4 to 1W, PRP or Vishay Dale.
Here is a link for the PRPs: Sonic Craft High-End DIY Audio Parts

The locations and Values of the Bias resistors are: on the Mainboard
*R60 (was R68) 33K
R71 (was R77) 10K
R59 (was R67) 220K
R61 (was R69) 220K*

One last preventive measure, On the rear of the chassis the speaker output jacks should have separate grounds installed. the 4&8 ohm jacks are grounded through the 16 ohm jack, (which Bypasses via an open/close contact), the 4&8 Ohm jacks when the 16 Ohm is used. Sometimes this contact doesn't close because of Dirt etc. so when You are plugged into the 4, 8, or Both, the Amp is actually seeing No load at all and: Bye-Bye OT and Maybe more. If You use only the 16 Ohm jack this is not a concern. This can be accomplished by soldering a short piece of wire to the shoulder of W6 Ground connection and to one of the metal bands on either the 4 or 8 ohm jack that is closest to the inside rear surface of the Chassis. When this is done however there will be no auto disconnect. ALL 3 jacks will be active ALL the time. Please DO NOT try and run 3 Cabs at the same time!!!

Now for the FUN Stuff:

Replace the OT and Add a Choke.

Add a 3H Choke at the *R63 (was R71) Resistor (270R 7Watt)* on the Mainboard. Remove *R63 (was R71) * and connect the two wires for the choke in its place. You can mount it behind the power Trans at the Rear of the Chassis. You will need to swing the Powerboard out of the way for drilling. TIP: Because this resistor is mounted with a LOT of solder, (and I was a little afraid of overheating and lifting the traces), I simply snipped the body off the Legs and soldered my wires directly to the leg remnants. Very un-professional and very effective.

A MAJOR sound Modification is the replacement of the puny Stock Dagnall OT. JCMJMP has drop in replacements on: Marshall DSL
Also they are available from Mercury Magnetics, I believe Jon deals in these. Because I had a deal fall into my lap, I used a replacement for a 100 Watt Plexi: a Dagnall C1998 or the Later version C2668. These you can find on Ebay or VERY good Clones from Marstrans or Metro Amp.


----------



## Razvan S.

BTW guys, wouldn't the 3H Choke make the amp kind of loose? Wouldn't a 5H or even a 7H be better?
Thanks!


----------



## DonP

RickyLee said:


> I guess the disparity between many DSL's that left the factory not created equal continues. And now I see there is no magic in the year of '98.



There is magic in 1998 or there is not?



RickyLee said:


> My first DSL100 was from '04. I did the mods you mentioned above and then some. When it was stock, it seemed to be very much like you describe. Mine had this fizz in the upper mids that was hard on the ears and just could not be dialed out unless I killed the top end with very low treble settings, mainly on the Red channel I should add. But the entire amp did have an unpleasant plastic sterile tone about it until it was cranked to such a high level that would drown out an entire band and piss off bar managers for sure.
> 
> Then I got a second stock DSL100 from '98 that was at the opposite end of the spectrum. The Red channel was slightly more midrangey but in a very good way. Sweet crunch and very good tone at lower volume settings. I still have not touched this '98 for mods except for installing a choke. There seems to be many more very good ones and bad ones out there with inferior tone and heat/bias issues than ones that are just in the middle of the road for tone. This amp was obviously produced more than any other Marshall that I know of, so that has to play into the recipe with the ingredients just having a slight variation in the final tone outcome.
> 
> I would think your mods should work out for you. Did you try them yet?



The reason I ask is that I have a 1998 Orange Crush which I bought new. No modifications yet. Original Wing =C= Tubes biased at 35ma each. I'm a bedroom player so this half stack has never been abused.

I have always been happy with the sound. Had many people on craigslist come over and say it sounded great.

I don't have any issues, but I'm tempted to do some reliability mod (C46, 5K6 for the grids, output jack grounds even though I only use 16ohms).

I'm curious if you still like your '98, and if you think the choke was a good addition.

Thanks.


----------



## RickyLee

DonP said:


> There is magic in 1998 or there is not?
> 
> 
> 
> The reason I ask is that I have a 1998 Orange Crush which I bought new. No modifications yet. Original Wing =C= Tubes biased at 35ma each. I'm a bedroom player so this half stack has never been abused.
> 
> I have always been happy with the sound. Had many people on craigslist come over and say it sounded great.
> 
> I don't have any issues, but I'm tempted to do some reliability mod (C46, 5K6 for the grids, output jack grounds even though I only use 16ohms).
> 
> I'm curious if you still like your '98, and if you think the choke was a good addition.
> 
> Thanks.



Hmmmm. I am confused by myself on that first quote from me above LOL. Was I talking about my 1998 DSL100? As for the '98 DSL100 compared to my 2005 (I think that is the correct year LOL) DSL100 with both of them being in stock from the factory form, the '98 was quite a bit different tonally, in a much better way all around. The '98 does not have as much disparity EQ wise going from the Green to Red channels. The Red channel on that amp is actually the highlight, mainly Lead 1. When I first got it, took it to my friends for a jam and my singer from my then cover band and quite a few musician buddies were blown away by how great it was sounding. And quite a few of them have no idea about the DSL amp history.

I know I had swapped all transformers in the 2005 DSL100 and installed a 3H choke as well. But I am not remembering installing a choke on my latest '98 DSL100. I have way too many amps to keep track of and my memory must be getting worse too LOL. Would have to check that but the DSL is somewhat buried away right now.

Did I mention somewhere in this thread about adding a choke to the '98 sometime in the last two years?


----------



## DonP

RickyLee said:


> Did I mention somewhere in this thread about adding a choke to the '98 sometime in the last two years?



I thought you said you did on a prior post in this thread.

After thinking it over, I've decided to leave my 1998 stock. It's been a great amp for 20 years, so why mess with a good thing.

Thanks.


----------



## RickyLee

DonP said:


> I thought you said you did on a prior post in this thread.
> 
> After thinking it over, I've decided to leave my 1998 stock. It's been a great amp for 20 years, so why mess with a good thing.
> 
> Thanks.



Yes, I did put a 3H choke in that '98 DSL100. Had to refresh my own memory.

I have some clips of that amp in action from a few gigs, before the choke was installed. That is to this point the only mods that amp has. Oh yes, I think I also upgraded all the components in the bias circuit, which is not really mods in my book. And did the speaker jack ground fix as well. But otherwise, that amp is awesome in stock form. My 2005 was another story for sure.

Are you inquiring about a 1998 Orange amp? Or is it a 1998 DSL 100 that you also have?


----------



## dslman

RickyLee said:


> Yes, I did put a 3H choke in that '98 DSL100. Had to refresh my own memory.
> 
> I have some clips of that amp in action from a few gigs, before the choke was installed. That is to this point the only mods that amp has. Oh yes, I think I also upgraded all the components in the bias circuit, which is not really mods in my book. And did the speaker jack ground fix as well. But otherwise, that amp is awesome in stock form. My 2005 was another story for sure.
> 
> Are you inquiring about a 1998 Orange amp? Or is it a 1998 DSL 100 that you also have?


Did your 98 have Drake trannies? I imagine that along with a choke means a lot.
The few 2K 100's I went through all had Dagnal's and I felt they were always a bit sluggish.


----------



## soundboy57

I have a 2000 DSL100, and it always sounded great. Played it live for years.
I have had four different TSL heads (sold years ago) and three out of four sounded quite good.

Just a guess, but it could be tranformer inconsistancy that causes some to sound "not great"??
I swapped power trannies in the best sounding one, and the worst sounding one, and they switched around.
By bad, I mean kinda harsh/lifeless no matter what tubes or bias.

My DSL100 has a Mercury output tranny and choke, and I removed the bright caps from both channels.
I did no other mods, other than swapping out the bias resistors to high heat metal film, and lowering the grid block resistors
from the 220K (yuck) to carbon comp 5.6K.
It sounds KILLER through every cab I have plugged in to...especially vintage cabs 

IMHO, those amps are plenty bright...no need for any bright cap, even a lower value, will still boost the fizz on top.
If your speaker cab is healthy, a bright cap shouldn't be required, IME.

Without one, you can then turn down the gain to 5 or 6, and get more vintage bluesy crunch tones, without the thin brightness.
Unbelievable that Marshall put a 470pf bright cap in those amps. OUCH.

I recently discovered that the JJ 6CA7 made my DSL sound incredible. Balanced and crunchy and alive, without too much bass.
I have used E34L and EL34II in it before, and liked the EL34II the least.

I also bias mine way lower than the 90mv per side recommended. More like 82mv or so. Much better tone and definition.

My two cents


----------



## RickyLee

dslman said:


> Did your 98 have Drake trannies? I imagine that along with a choke means a lot.
> The few 2K 100's I went through all had Dagnal's and I felt they were always a bit sluggish.



I am thinking only 50W DSL50 amps had the Drakes, and then that was not for long. Maybe first year or two? 1997 only? Then they all went to Dagnalls.

I am not knowing of the old JMP's, but with the JCM800, the 100W amps had Dagnall and the 50W amps had Drakes. The Dagnalls were high quality up until around 1990. At least that is my opinion. Even the Drakes changed during the JCM900 era as they went to those laydown output xfmrs which seemed to be a bit smaller. Maybe I am wrong on the latter and they did not get smaller? Sure seems that way when I look at my JCM800 50W amps compared to my JCM900 MK3 and JCM900 SL-X 50W amps.


----------



## RickyLee

soundboy57 said:


> I have a 2000 DSL100, and it always sounded great. Played it live for years.
> I have had four different TSL heads (sold years ago) and three out of four sounded quite good.
> 
> Just a guess, but it could be tranformer inconsistancy that causes some to sound "not great"??
> I swapped power trannies in the best sounding one, and the worst sounding one, and they switched around.
> By bad, I mean kinda harsh/lifeless no matter what tubes or bias.
> 
> My DSL100 has a Mercury output tranny and choke, and I removed the bright caps from both channels.
> I did no other mods, other than swapping out the bias resistors to high heat metal film, and lowering the grid block resistors
> from the 220K (yuck) to carbon comp 5.6K.
> It sounds KILLER through every cab I have plugged in to...especially vintage cabs
> 
> IMHO, those amps are plenty bright...no need for any bright cap, even a lower value, will still boost the fizz on top.
> If your speaker cab is healthy, a bright cap shouldn't be required, IME.
> 
> Without one, you can then turn down the gain to 5 or 6, and get more vintage bluesy crunch tones, without the thin brightness.
> Unbelievable that Marshall put a 470pf bright cap in those amps. OUCH.
> 
> I recently discovered that the JJ 6CA7 made my DSL sound incredible. Balanced and crunchy and alive, without too much bass.
> I have used E34L and EL34II in it before, and liked the EL34II the least.
> 
> I also bias mine way lower than the 90mv per side recommended. More like 82mv or so. Much better tone and definition.
> 
> My two cents



I agree about the possibility of the JCM 2000 transformers being a bit inconsistent. Could be partly why my '98 sounds so amazing. I know Adrian is the biggest advocate here for upgrading the DSL iron and adding a choke. But I have never been 100% on that side of the fence. My reason is my first TSL100 which is a 1998. That amp has the first Classic Tone DSL100/TSL100 power transformer made. I sent them my TSL100's power transformer to reverse engineer and they gave me the PT for my effort. I then later upgraded the output transformer to either the Clasic Tone . . . . or was it it the Lydian? Dam my memory is getting bad man LOL. Anyway, I did notice some increase in bandwidth slightly. But I ended up thinking the original output xfmr had a sweeter tone, almost like it would go into early saturation and give up sweet harmonic blooming and overtones. Then to where the upgraded OT had more headroom and did not have the same sweet character. My thing with these amps is opposite of what everybody preaches they are designed for . . . . I do not care for a clean power stage. I want some breakup and saturation in my power amp stage.

Interesting you bring up those JJ 6CA7's. I have been thing about the sets I have stashed away from many many years ago. I did some testing with them all those years ago and I was blown away how they responded in a few different amp heads. The big shocker was my 2500 SL-X. Wow. I need to revisit those and try them in my JVM410H and my hot rodded 2204 build.

Lately, I have been getting this urge to go back inside my 2nd TSL100 which is the 2005 model. I did a few minor things to it already, but I am considering doing a major hacking to that thing. What keeps me from digging in is the pain in the ass they are to work on . . . .


----------



## dslman

RickyLee said:


> I am thinking only 50W DSL50 amps had the Drakes, and then that was not for long. Maybe first year or two? 1997 only? Then they all went to Dagnalls.
> 
> I am not knowing of the old JMP's, but with the JCM800, the 100W amps had Dagnall and the 50W amps had Drakes. The Dagnalls were high quality up until around 1990. At least that is my opinion. Even the Drakes changed during the JCM900 era as they went to those laydown output xfmrs which seemed to be a bit smaller. Maybe I am wrong on the latter and they did not get smaller? Sure seems that way when I look at my JCM800 50W amps compared to my JCM900 MK3 and JCM900 SL-X 50W amps.


I did the Classictone O/T and Choke on my 2004 DSL50. It did change the tone a bit, but I am pleased with the change , and the tightness that was added. 
I can only imagine the 100 would be similar, and should also quiet down those noisey Dagnall's.


----------



## RickyLee

dslman said:


> I did the Classictone O/T and Choke on my 2004 DSL50. It did change the tone a bit, but I am pleased with the change , and the tightness that was added.
> I can only imagine the 100 would be similar, and should also quiet down those noisey Dagnall's.



You just reminded me that my 2005 DSL100 did have some slight vibration type buzz noise on its stock power transformer.

The Classic Tone PT upgrade is supposed to have a 10% reduction in the power supply voltage, which is good for these amps and the power tube life in general. Plus it would help to reduce the high voltage that these amps see on the V3 12AX7 cathode follower position. I think the latter is why people see certain 12AX7 brands fail in that location.

The power transformer Classic Tone made for me did not have 10% lower secondary HT, but it lowered my B+ about 10V -15V. I would liked to have about 30V - 40V reduction as my wall voltage here where I live runs about 125VAC.


----------



## DonP

RickyLee said:


> Are you inquiring about a 1998 Orange amp? Or is it a 1998 DSL 100 that you also have?



No, I bought this Orange Crush 1/2 stack new at a dealer in Newport, KY in the fall of 1998. One of the EL34's blew a fuse in the first months of ownership, and I replaced that one tube. Still on the original tubes.

I'll have to check to see what make the trannies are.

The tone of this amp was sort of bright and harsh when I bought it, but I believe it was the speakers (75's) breaking in. As it aged, it's gotten smoother and sweeter.

Call me odd, but I just dime all the controls. My favorite is red OD1 with bass boost on, or green crunch with bass boost off.

On the red channel I get my Maiden Priest and other classic tones. On the Green channel I get def Leppard, GnR, Thin Lizzy, etc depending on which axe and pickups I choose.

Mid Cut button on red can get me thrash tones like Metallica.

I have a Randall Lynch Box and a Laney AOR 50 head also to go through the same cab. The Randall compared to the DSL100 is "cleaner" and more open sounding, but I find it more sterile. I like the warmth of the DSL100 better.

The Laney gives me the JCM800 tones in spades, but is a one-trick pony. A very good one trick pony.

I've had the Laney since 1990 (bought in Hollywood), and the Randall is the newest in 2013. I love the flexibility of the Randall (got 9 modules but none modified).


----------



## soundboy57

My bitch with the TSL (and I used one for years live) is the crunch channel.
The clean channel was great, and the lead was great. The crunch just had too much of a compressed
thin mid centered tone to it, no matter what I did. 
If they had done a DSL green tone on the TSL crunch, it would have been the ultimate channel switcher


----------



## RickyLee

DonP said:


> No, I bought this Orange Crush 1/2 stack new at a dealer in Newport, KY in the fall of 1998. One of the EL34's blew a fuse in the first months of ownership, and I replaced that one tube. Still on the original tubes.
> 
> I'll have to check to see what make the trannies are.
> 
> The tone of this amp was sort of bright and harsh when I bought it, but I believe it was the speakers (75's) breaking in. As it aged, it's gotten smoother and sweeter.
> 
> Call me odd, but I just dime all the controls. My favorite is red OD1 with bass boost on, or green crunch with bass boost off.
> 
> On the red channel I get my Maiden Priest and other classic tones. On the Green channel I get def Leppard, GnR, Thin Lizzy, etc depending on which axe and pickups I choose.
> 
> Mid Cut button on red can get me thrash tones like Metallica.
> 
> I have a Randall Lynch Box and a Laney AOR 50 head also to go through the same cab. The Randall compared to the DSL100 is "cleaner" and more open sounding, but I find it more sterile. I like the warmth of the DSL100 better.
> 
> The Laney gives me the JCM800 tones in spades, but is a one-trick pony. A very good one trick pony.
> 
> I've had the Laney since 1990 (bought in Hollywood), and the Randall is the newest in 2013. I love the flexibility of the Randall (got 9 modules but none modified).



What I never understood, is why the heck hasn't the Randall amp with all those plug in preamp modules not take off and become the best thing since sliced bread. When I first heard of that rig, I was blown away and thought to myself "That is the ticket right there man!" You have all those different preamp options right there for any tone you could desire. Is something not right in the design? I have never played one myself. But the concept seems amazing to me. What is the deal with that amp?



soundboy57 said:


> My bitch with the TSL (and I used one for years live) is the crunch channel.
> The clean channel was great, and the lead was great. The crunch just had too much of a compressed
> thin mid centered tone to it, no matter what I did.
> If they had done a DSL green tone on the TSL crunch, it would have been the ultimate channel switcher



On one of my TSL100's, the first one which is the '98, the Crunch channel was the highlight. I would end up staying on that channel all night for bar gigs and never even switch over to Lead for solos. Then I would just back off my guitar volume a bit for cleaner stuff and it worked out great.

On my 2nd 2005 TSL100, I tweaked the first interstage a bit on the Crunch channel. It is quite tasty now for sure. And what I found about the Red Lead is it sounds its best when I push in the TONE SHIFT and dial it in for a more mid scooped tone and use it that way. So it is not a lead soloing channel, but just another flavor of tonal shaping. And I can dial it in with MIDS actually about 6 Treble 7 and Bass 5 and it still sounds a bit mid scooped but just massive, bold, lots of grind. Like a Godsmack, Metallica Black album type sound.

On the TSL, the Crunch and Lead use all 5 of the gain stages. On the DSL, Red channel uses all 5 gain stages while Green uses only 4 gain stages. That is why DSL Crunch and TSL Crunch are so different. On the TSL, the Red is just an extension of Crunch. A more gained up version with a higher value treble peaker, a cathode bypass cap across 2nd stage (Crunch does not have 1uF across 2nd stage cathode) and a 1MEG gain pot where Crunch has a 200K gain pot.


----------



## dslman

RickyLee said:


> What I never understood, is why the heck hasn't the Randall amp with all those plug in preamp modules not take off and become the best thing since sliced bread. When I first heard of that rig, I was blown away and thought to myself "That is the ticket right there man!" You have all those different preamp options right there for any tone you could desire. Is something not right in the design? I have never played one myself. But the concept seems amazing to me. What is the deal with that amp?
> 
> 
> 
> On one of my TSL100's, the first one which is the '98, the Crunch channel was the highlight. I would end up staying on that channel all night for bar gigs and never even switch over to Lead for solos. Then I would just back off my guitar volume a bit for cleaner stuff and it worked out great.
> 
> On my 2nd 2005 TSL100, I tweaked the first interstage a bit on the Crunch channel. It is quite tasty now for sure. And what I found about the Red Lead is it sounds its best when I push in the TONE SHIFT and dial it in for a more mid scooped tone and use it that way. So it is not a lead soloing channel, but just another flavor of tonal shaping. And I can dial it in with MIDS actually about 6 Treble 7 and Bass 5 and it still sounds a bit mid scooped but just massive, bold, lots of grind. Like a Godsmack, Metallica Black album type sound.
> 
> On the TSL, the Crunch and Lead use all 5 of the gain stages. On the DSL, Red channel uses all 5 gain stages while Green uses only 4 gain stages. That is why DSL Crunch and TSL Crunch are so different. On the TSL, the Red is just an extension of Crunch. A more gained up version with a higher value treble peaker, a cathode bypass cap across 2nd stage (Crunch does not have 1uF across 2nd stage cathode) and a 1MEG gain pot where Crunch has a 200K gain pot.


Some good stuff there. I always loved the tone of the TSL, and actually bought a 100watt head that sounded great, but had what I know now was probably just a bad tube, but that was before I knew anything about repairs and tubes, so I returned it for the DSL.


----------



## DonP

RickyLee said:


> What is the deal with that amp?



If I was performing, it would be my go-to. It works great for everything non-Marshall, but for Marshall tones I like the DSL more. I have the Plexi, SL+, Mr Scary, and Judge modules which are all flavors of Marshall. They all sound good, but just different. i like the effects loop choices and the ability to pick your output tubes. That might be the issue - having an output tranny that can take anything from KT88 to 6V6 won't be as fine tune as a tranny specifically spec'd for EL34's running full out.


----------



## RickyLee

dslman said:


> Some good stuff there. I always loved the tone of the TSL, and actually bought a 100watt head that sounded great, but had what I know now was probably just a bad tube, but that was before I knew anything about repairs and tubes, so I returned it for the DSL.



The TSL has just a few deviations off of the recipe that gives it that slightly different flavor than the DSL. On this second TSL100 I got, I went in and changed a few things that I thought would give it that slightly darker nudge in the direction of the DSL circuit. The main change is a small value cap that bleeds some highs off to ground. The DSL has a slightly higher value there than the TSL which helps give it that darker tone that I think lends to some of the reason most people favor the DSL over the TSL. Also, there is a 2n2 coupling cap coming out of that 2nd gain stage on the TSL. The DSL has a 4n7 there which give the DSL a bit more low end. Then, factor in the DSL having a hotter first gain stage 220K plate where the TSL uses a 100K there. That is really the main tonal differences between the two amps right there.

So now that the new DSL uses the JVM type switching that allows access to all four modes, that is a huge plus over the TSL. But then, the DSL is still having to share one EQ section for all four modes.


----------



## dslman

RickyLee said:


> The TSL has just a few deviations off of the recipe that gives it that slightly different flavor than the DSL. On this second TSL100 I got, I went in and changed a few things that I thought would give it that slightly darker nudge in the direction of the DSL circuit. The main change is a small value cap that bleeds some highs off to ground. The DSL has a slightly higher value there than the TSL which helps give it that darker tone that I think lends to some of the reason most people favor the DSL over the TSL. Also, there is a 2n2 coupling cap coming out of that 2nd gain stage on the TSL. The DSL has a 4n7 there which give the DSL a bit more low end. Then, factor in the DSL having a hotter first gain stage 220K plate where the TSL uses a 100K there. That is really the main tonal differences between the two amps right there.
> 
> So now that the new DSL uses the JVM type switching that allows access to all four modes, that is a huge plus over the TSL. But then, the DSL is still having to share one EQ section for all four modes.


Wow, very interesting and great knowledge on the voicings.
Have you ever compared the circuit of the DSL100H to the 2K DSL100?
I'm really pleased with the 100H, and would never mod it in any way.


----------



## RickyLee

dslman said:


> Wow, very interesting and great knowledge on the voicings.
> Have you ever compared the circuit of the DSL100H to the 2K DSL100?
> I'm really pleased with the 100H, and would never mod it in any way.



Never had a DSL100H in front of me. I have looked at the schem and like a few things Marshall changed. The main one is the reverb circuit was moved one stage farther down in the signal path. Seems like the reverb should sound better and cleaner. Does that 100H have a reverb tank, or is it digital reverb?


----------



## dslman

RickyLee said:


> Never had a DSL100H in front of me. I have looked at the schem and like a few things Marshall changed. The main one is the reverb circuit was moved one stage farther down in the signal path. Seems like the reverb should sound better and cleaner. Does that 100H have a reverb tank, or is it digital reverb?


It's digital, I need to explore it more before I comment on it though.
The clean channel is very clear and chimney , but that's how I use the Green CH.
The 100H vs 2k is more big bold and full where the 2K is more focused and thinner for lack of words.
I just wonder why there is such a difference, maybe just a different layout all together.
The green and red channels are seamless , where the 2k's take some work to achieve this.


----------



## RickyLee

dslman said:


> It's digital, I need to explore it more before I comment on it though.
> The clean channel is very clear and chimney , but that's how I use the Green CH.
> The 100H vs 2k is more big bold and full where the 2K is more focused and thinner for lack of words.
> I just wonder why there is such a difference, maybe just a different layout all together.
> The green and red channels are seamless , where the 2k's take some work to achieve this.



I think that is the other cool feature I noticed, is Marshall went to e relay coil switching scheme for the channels vs the old LDR's that had bad latency and lag. That was the other thing I was trying to mod out of my old JCM 2000 amps - the latency in switching and swelling of the reverb up/down when switching channels.


----------



## dslman

The 100H has the big stand up trannies , funny thing , I couldn't even tell you what kind they are. I really need to learn more about the amp, I just like it so much that I haven't took the time to critique it.
I've been battling tinnitus so bad , I contemplated selling everything I have , including guitars.
I should have taken much better care of my ears.


----------



## dslman

RickyLee said:


> I think that is the other cool feature I noticed, is Marshall went to e relay coil switching scheme for the channels vs the old LDR's that had bad latency and lag. That was the other thing I was trying to mod out of my old JCM 2000 amps - the latency in switching and swelling of the reverb up/down when switching channels.


The switching is real nice now that you mention it, and the amp idles dead quiet, like it's almost not on.


----------



## RickyLee

And didn't they make the power tube sockets isolated off the main PCB?

It baffles me as to why the price of the old JCM 2000 amps have not dropped big time due to all the new DSL line including the DSL100H? Maybe it is due to the old 2000's being made in the U.K.? It is no big deal to me where my amp is made as long as the quality is good.


----------



## dslman

I had to replace the reverb tank on my 2K as most do, more of a repair than a mod I suppose.
I just used the MOD brand and it's not too bad. I actually use it for a slight effect.
Next time I play , I'll compare the 100H digital to it, as I haven't even tried it yet...lol


----------



## dslman

RickyLee said:


> And didn't they make the power tube sockets isolated off the main PCB?
> 
> It baffles me as to why the price of the old JCM 2000 amps have not dropped big time due to all the new DSL line including the DSL100H? Maybe it is due to the old 2000's being made in the U.K.? It is no big deal to me where my amp is made as long as the quality is good.


Good points, my only gripe on the 100H, is the cabinet, supposedly it's HDF, not MDF, but either way, I'd rather it be any kind of real wood, except balsa.
I haven't had any issues with it, I just don't throw it around like the old heads.


----------



## dslman

Yeah the sockets are like you say.chassis mounted
I think they really made some great improvements


----------



## dslman

There is a VooDoo mod called Sennas mod, named after Steve Sennas, he's a really good guitarist that uses this forum sometimes.
Besides the trannies and choke, I'd love to know that recipe on that one for the 2K DSL.


----------



## sfb

Does anybody have schematic for the iss20 mainboard?


----------



## SonVolt

Whatever happened to @*TwinACStacks? *


----------



## Razvan S.

Gotta be honest with you guys. I am torn between modding it or not in the end.
To me, mine sounds OK (even on lower volumes) -> I have the 2009 Model

Some samples at LOW volumes, no attenuation(cab is with 2x G12K100)

With a scalloped modified Squier:


This has some chorus in the first round, then I take it out and tweak the channel differently:


----------



## Micky

SonVolt said:


> Whatever happened to @*TwinACStacks? *


He found a better forum to hang out at.


----------



## Zentoorama

Good day to everyone! Since there are newer dsl models, can someone transcribe those mods for DSL 100-60-00 iss1 boards?
I have a schematic for thease.


----------



## Ghostman

Zentoorama said:


> Good day to everyone! Since there are newer dsl models, can someone transcribe those mods for DSL 100-60-00 iss1 boards?
> I have a schematic for thease.


These wouldn't translate to the newer versions of DSLs. This is for the original JCM2000 versions.


----------



## Zentoorama

Ghostman said:


> These wouldn't translate to the newer versions of DSLs. This is for the original JCM2000 versions.


Definately would. Couse I watched schematic and found a looot of common in both amps. Actually I will make a post of changes a little bit later. Changes remain the same, but number of parts that needs to be changed is different. Consider that changing c19 in a new model is the same as changing c12 in an old model. And so on.


----------



## Zentoorama

Done all joey mods on a new amp except that what is wrote in green, and "choke" part. The amp sound brilliant after those mods!


----------



## Zentoorama

This is a link for schematic I mentioned before: http://music-electronics-forum.com/attachments/47307d1519622857-marshall-dsl100-60-02-v02.pdf


----------



## Micky

Zentoorama said:


> This is a link for schematic I mentioned before: http://music-electronics-forum.com/attachments/47307d1519622857-marshall-dsl100-60-02-v02.pdf


This schematic is nothing new. It is, and has been commonly available for over 5 years now. Comparing this to the previous JCM2000 version yeilds several significant differences, not lending the new version to bode well with the older JoeyMods.

It might be best for you to implement the mods you desire at your own risk, and then post the results in a new thread. But then again, I am sure that if you do the research, especially on the DSL40c Info thread you will find many of the same or similar mods already documented.


----------



## Zentoorama

OK transcription I promised before. 
All values of condensers and resistors stay the same.
white is for JCM2000 Green is for DSL 100H 

Front Board: 

NOTE: THESE MODS AFFECT THE RED LEAD 2 MODE ONLY (removing C12 will also darken Lead 1)

1M Resistor from Wiper to Ground on Vr3 **** *VR 3*
C12 Lower to 150pf or REMOVE (I removed it) *C19*
C10 replace with .0022 uf* C23*
R20 Remove and *JUMPER R26*


Mainboard: 

NOTE: THESE MODS AFFECT ALL CHANNELS/MODES

C9 *- C11* replace with 1000pf (.001uf) 500V
C12 - *C12 *replace with 1uf 63V

Here is a Link for the Caps:

MKS2-1/63/5T WIMA Polyester Film Capacitors


Now if You find that the overall texture of the amp is, or has become too dark:
*
*
Mainboard:

Replace R30 - _*R42*_ (470k)with 68k to 220k resistor this will Decrease the Fizziness and the OVERALL GAIN as well and also brighten the Amp. I personally Piggybacked, (using a pair of test leads), a range of resistors across the Legs of R30 from 82k to 1M and decided I liked 1M the Best. This brought the Value of R30 to 320k. I then soldered it in place across the legs of R30. This way it is easily changed if I decide on a different value without pulling the PIA Mainboard!!! This particular Mod is pretty much season to taste. One of the Techs or Myself can figure out what value you need for "Piggybacking", or you can try and figure it out yourself:

R1XR2 Divided By R1+R2= the Total resistance of Both Resistors combined. Use the Value of R30 (470)k for R1 and the resistor You want to try as the value for R2. (Try: 82k, 120k, 220k, 330k, 470k and 1m)

Also if You find that the Green CRUNCH Mode is too boomy especially with the deep switch engaged:

Frontboard:

C8 - *C6* replace with .001uf to .0022uf (I used .0015uf)

Here's a link: http://www.mouser.com/ProductDetail...EpiMZZMsh%2b1woXyUXjyBw8LYChpgf%2bpPFAhHPmAM=


----------



## Zentoorama

Micky said:


> This schematic is nothing new. It is, and has been commonly available for over 5 years now. Comparing this to the previous JCM2000 version yeilds several significant differences, not lending the new version to bode well with the older JoeyMods.
> 
> It might be best for you to implement the mods you desire at your own risk, and then post the results in a new thread. But then again, I am sure that if you do the research, especially on the DSL40c Info thread you will find many of the same or similar mods already documented.



Already done that. Everything works. But I didnt find ANY info for this particular amp.
All I could find was C19, and nothing else.


----------



## Ghostman

Zentoorama said:


> Already done that. Everything works. But I didnt find ANY info for this particular amp.
> All I could find was C19, and nothing else.


The problem I find, is that the disparity between Green and Red channels with the new versions of DSL100h and the very new DSL100hr, aren't there like the old ones. The JCM2000 DSL and the newer versions of DSL100h and 100hr sound so much different that I'd be super hard pressed to even try these mods.


----------



## Exojam

I was wondering if someone could be so kind as to straighten out my mind here on this question.

On the first post TwinACStacks stats the mods listed will work on these two boards JCM2 60-02 iss5 (Tube) AND JCM2 61-00 iss1 (Front). I opened up my amp and only have one main (large) board stamped Marshall DSL100-60-00 Issue 1 (picture attached). This board also has V1-V4 on it. There is only one other vary same board attached to this one.

So my question is what board would this actually be considered, I am assuming the “Front” but would like verification so I can move forward with the mods and to also replace R79, 81 and 106 since I will be converting the power tubes to 6550.

I have also attached two other pictures showing some of the resistors mentioned in the first post.

View media item 10206

Thanks very much.


----------



## Micky

Joey Mods only pertain to the JCM2000 series DSL.


----------



## Exojam

Thanks Micky. 

So it looks like I just need to do the three resistors for the new tubes. Easy enough.


----------



## Mark Simon Hell

so.. only a video (on youtube) about this mod.. any soundclips?
thanx


----------



## Parkerx02

C8 replace with .001uf to .0022uf (I used .0015uf)… What does this do?


----------



## Sprywatt

G'day Marshallforum...this is my first post. Today I bought a 2006 Jcm2000DSL. I was after something that had the ability to switch between clean and gain so here we are.

Before I ask this question, I am an electronics technician, so please don't be concerned for my safety =].

I wanted to confirm the position of the choke, the photos I uploaded, it will go above the pcb where the mains chord plugs into? Which is closest to the rear of the chassis? I'm assuming the companies I've seen that provided the choke for this mod make the leads long enough to get to R71?

Thanks for any help =]


----------



## CROWEMAG

I want to do the R12 mod on my 1998, stock DSL100. Is this R12 on the pot board? 

I also want to do the C12 mod for flubby bass. Is this C12 on the main (tube) board? 

No issue number so I assume this is the first board made for these. Thanks!


----------



## CROWEMAG

Sorry....just found it. ISSUE 345 whatever that means


----------



## burger

Kudos to this thread and to Joey, the info here was a great start to the ending point documented here.


----------



## ledvedder

burger said:


> Kudos to this thread and to Joey, the info here was a great start to the ending point documented here.



This sounds great. I'm wondering if similar mods can be done to my DSL40c? I'm assuming the component numbering is different?


----------



## Caspercody

I have both schematic’s for DSL100 (from Jason’s site) and DSL40C and they look identical. Same parts numbers and values


----------



## ledvedder

Caspercody said:


> I have both schematic’s for DSL100 (from Jason’s site) and DSL40C and they look identical. Same parts numbers and values


So I could follow the mod instructions from Headfirst on my DSL40c? Same board locations as well?


----------



## Caspercody

From what I am seeing, yes.


----------



## ledvedder

burger said:


> Kudos to this thread and to Joey, the info here was a great start to the ending point documented here.



Does anyone have the BOM for the parts needed for these mods? Mouser has so many components, so I want to be sure I'm ordering the correct ones.


----------



## ledvedder

burger said:


> Kudos to this thread and to Joey, the info here was a great start to the ending point documented here.



I performed this mod on my DSL. Now I'm getting very low volume and barely any gain on the red channel. Green channel is working fine. Any pointers where to start troubleshooting?

Here's a video of the issue, along with a pic of the work by the gain pot.

https://youtube.com/shorts/IeZwQDqm2i0?feature=share


----------



## nkd

@ledveder - It sounds that not all of the input signal is reaching the grid of V1B or even bypassing the tube. Also check the solder at the grounded end of R34.


----------



## ledvedder

nkd said:


> @ledveder - It sounds that not all of the input signal is reaching the grid of V1B or even bypassing the tube. Also check the solder at the grounded end of R34.


Hmm, I didn't touch R34.


----------



## ledvedder

Here's another video I made, walking through the mods that I made. Sorry for the lack of focus on my camera. I'm really hoping someone can help me out.


----------



## rjohns1

I performed the Headfirst mods on my DSL40CR, I had to compare schematics side by side with his DSL40C print, but most components are in the same spot, just have a different part number. Really happy with the mod. Definitely changed the ultra channel to a more vintage sounding one.


----------



## ledvedder

I had the first full band rehearsal with my Headfirst modded DSL40c last night. I'd done a few changes beyond the published mod, since I wanted to decrease some lower bass frequencies. Perhaps this is due to the Creamback 65 I've put in it? Not sure. I changed both R27 and R42 to 220k. Jason mentioned R42 in the mod video, but said he put it back to stock. It seemed fine in my work room at home, but once I was with the band, it just didn't feel like it had enough oomph. It just felt dull, compared to how it had previously sounded. So, tonight I put R42 back to the stock 470k. Hopefully, this improves how it performs in the full band mix.

Also, previously, I had changed C19 to 100pF. When I did the mods, I left that, instead of going with 220pF. I'm wondering if that would also make much of a difference?


----------



## rjohns1

c19 makes the most difference if your gain is below half way. As you turn up the gain, it doesnt do much. Where do you typically have the gain at? Depending on what type of guitar or pickups, it might sound better or worse. Do you like 100pf?If you want a little more sizzle, go higher. If not leave it.


----------



## rjohns1

So I had a few days with the head first mods in my 40CR. I found that when I turned it up, it was too bright. I stuck the two 480pf caps back in after the gain stage. I have noticed that the real star of the show is the second stage cathode resistor, that is what really changed the character of the ultra channel. It takes the smooth high gain distortion and makes it crunchier. I might put mine on a switch, I like it for some stuff, but would be cool to get a smoother gainier sound at the push of a button. I found a push button that a round black cylinder that is comparable to the channel mode switches. I might add it to the front panel. It would be a Vintage/Modern mode switch. I did some calculations, and if I put a 5k in parallel with the 2.8k that is in there now, it gets me a combined value of 1.7k, the stock value. I might play with this to see if there is somewhere between the two that sounds cool too. That resistor controls the bias of that gain stage, and 1.1k drastically changed the character. Should be interesting.


----------



## ledvedder

rjohns1 said:


> So I had a few days with the head first mods in my 40CR. I found that when I turned it up, it was too bright. I stuck the two 480pf caps back in after the gain stage. I have noticed that the real star of the show is the second stage cathode resistor, that is what really changed the character of the ultra channel. It takes the smooth high gain distortion and makes it crunchier. I might put mine on a switch, I like it for some stuff, but would be cool to get a smoother gainier sound at the push of a button. I found a push button that a round black cylinder that is comparable to the channel mode switches. I might add it to the front panel. It would be a Vintage/Modern mode switch. I did some calculations, and if I put a 5k in parallel with the 2.8k that is in there now, it gets me a combined value of 1.7k, the stock value. I might play with this to see if there is somewhere between the two that sounds cool too. That resistor controls the bias of that gain stage, and 1.1k drastically changed the character. Should be interesting.


Is that R18?


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## rjohns1

Yes, it is a different number on the CR. R18 in the 40C. That part made the most drastic change from what I could tell so far.


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## ninjagrips

I just got my DSL50 back from getting the Joey mods, as well as all the "safety" mods, a choke and a NFB pot on the rear of the chassis.

One thing that the tech did not do, that I actually asked him to do, was to try and get a little more gain out of the green channel.

I would normally just take the head back to the tech and ask him to complete the work, but he already forgot to add the NFB pot while he was in there, as he came upon another issue while working on it, then forgot about the NFB mod. He finally did add that NFB pot, and I took the amp home.

I love the way the amp sounds now, the only thing I wish is that I could get just a touch more gain out of the green channel.

Did anyone ever say what the "Drunken Irishman" mod was? I'd love to know what I could do to get just a little more gain out of the green channel, without sacrificing too much of anything else.


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## ninjagrips

Buggs.Crosby said:


> i'm just getting into the red finally....a little has been done but not much yet
> instead i have the Drunkin Irishman mod from Joey.....i dont really do clean so we hoped up the green a bit....i cant tell you what was done but i can show you what can be done to the green on a DSL....this is a shitty vid recorded with a mike for a Wii....it is not about tone or playing....merely to show the gain .....all gains are maxed and the volume is under one...(just audible enough to record and not clip)
> [ame=[MEDIA=youtube]ADYxJqguGx0[/MEDIA] - 4 up 4 down.mpg[/ame]


This is exactly what I’m trying to get my Green Channel to sound like!

I wish I knew what was involved in inebriating that Irishman!


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## rockgod212

i forgot what i did to mine but i was able to get the green channel to sound like it should with more gain- it sounds like a hot rodded 800 now. i think i added a .47uf / .1uf cap over v2a stage cathode via a on off on switch, messed around with R38 and the NFB, i added a true resonance mod which thickened up the tone some, i might have revoiced the green channel on the pot board as well. it was a combination of various circuit changes. i will see if i can find my notes for what i did if i still have them i will list them, the green channel sounds so good now i dont even use the red channel. i would have to open the amp to see what i did which i cant do at the moment.


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## ninjagrips

Well that sounds right up my alley!

Any help, pics, etc. are greatly appreciated!

Did you also do the Joey Mods?

The more I play mine, I notice a bit of what seem to me to be some ice-picky highs. I'm not 100% sure, though. There is some ear-piercy-ness to it, but maybe that's just the Presence and maybe it needs to be there to cut through the mix better?

Also, the NFB pot mod doesn't seem to do a whole lot. I asked for a "Resonance" knob, in actuality, and I'm not sure NFB is exactly the same thing.


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## rockgod212

i tried to find my notes but i could not find them. i blew the v1 tube and i need to change that, so i will pull the amp out of the chassis and check and see what i all did. are you going to do the mods yourself? do you happen to know what pcb boards you have in your amp? download all the dsl100/ tsl100 schematics you can find cause there are quite a few and none of them are the exact same, so when i say change R38 it may not synch up in your amp as the same resistor in the same spot as in my amp. 

no i didnt do the joey mods, i might have tried a few here and there but in the end i opted to get the green channel to sound great. my amp has been ripped apart many times over the years.

to answer the nfb question, the nfb and resonance pot is interactive.

go head and PM me and i will help you out with this the best i can.


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## rockgod212

i forgot to mention that by getting the green channel to sound like a hot rod 800 or higher gain it does affect the red channel to some degree as this amp is not really a 2 channel amp in the sense of the word. it is really a 4 gain stage amp with a 5th stage switched in or out if that makes any sense.


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