# Dsl1 (2018 Vietnam Version) Mod's



## Mavrim

I bought a used DSL1 a few months ago for $230 total. Removed the chassis to investigate what was inside. I noticed that the output transformer had an unused wire inside that was tie wrapped in the wire bundle. After ohming it out I decided that it has to be an 8 ohm tap. The only output is 16 ohms. With these small one watt amps, it is ok to mismatch output impedance without damaging the amp. I read that one of the marshall designers did that with one of the 50th anniversary models to get better tone. I added another output jack next to the 16 ohm jack. When wiring it up, I found that marshall had swapped the ground and hot on the pcb spade connection. So I swapped them and wired in the new lead. I recall that it was white. With a meter I read 1.6 ohms on the 16 ohm output and .9 ohms on the unused lead that I assume is 8 ohms.

I set up my DSL1 using the new 8 ohm output that I installed. Cabinet is a lead 12 slant fitted with an 8 ohm 12" celestion vintage 30. I also swapped out the stock ECC82 power tube with an RFI ECC82. Amp sounded incredible! Then I switched the 8 ohm speaker to the factory 16 ohm output and it did not sound as good. So I can see this mod as being a good thing for those with 8 ohm cabinets.


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## Mavrim

Extra output lead tie wrapped in output transformer lead harness. 8 ohms???


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## Mavrim




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## Mavrim

Ground wire on 8 ohm output jack attaches to ground on PCB as shown.


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## Mavrim

8 ohm output jack added next to the original 16 ohm output jack. Need to label this as 8 ohms.


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## Mavrim

Next, thinking about adding a presence control, NFB in/out switch, cathode capacitor bypass switches...


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## Mavrim

PS - The built in attenuator switch for .1 watts only works on the original 16 ohm output and not on the additional 8 ohm jack. I will investigate that at a later time.


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## Mavrim

ECC82 output tube V3 goes directly to the output transformer. Plates connections 6 & 1 go to transformer. So there is no question of a mosfet output stage. I believe that the phase inverter is a mosfet design...


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## Mavrim

Thinking I might remove the additional 8 ohm output jack that I installed and replace it with a SPST toggle switch to select 8 ohm and 16 ohm. 16 ohm orange wire going to PCB would go to switch and 8 ohm white wire would go to opposite side of switch. Switch center would then connect where the orange wire went on PCB. This way the attenuator circuit would work for both outputs. The original 16 ohm output jack would now become selectable for 8 or 16 ohms. Too bad I drilled that large hole, now I need to use a large toggle. If doing this mod fresh, I would have used a mini toggle switch.


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## bobq

Hello everyone

I've made your modification to 8 ohm and it's works perfectly.

Thanks a lot

Is it possible to change valves to improve our sound?

Thanks a lot


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## paul-e-mann

Im hoping somebody can figure out a mod for these amps to rid some of the compression in its tone. Great little amps just too much compression for my liking.


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## slagg

Still looking for someone to find the bright cap on the clean classic channel.I think it effects both channels and will reduce a lot of the compression that is killing the tone.


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## slagg

can anyone tell me if c30 is the bright cap


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## ampmadscientist

pedecamp said:


> Im hoping somebody can figure out a mod for these amps to rid some of the compression in its tone. Great little amps just too much compression for my liking.



If you have the schematic it would be helpful.
Either that or the amp itself to draw a schematic from.

The basic Marshall formula is to compress the highs (the higher the frequency the more compression)
and to leave the lows clean.
The lower the frequency, the more clean it becomes in other words.

And when you hear "too much compression," it often means that the lower frequencies are being compressed too much....resulting in a kind of muddy overload when the amp is pushed.


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## paul-e-mann

ampmadscientist said:


> And when you hear "too much compression," it often means that the lower frequencies are being compressed too much....resulting in a kind of muddy overload when the amp is pushed.


Thats what Im hearing.


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## Micky

Has anyone found the schematic for this amp yet?


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## slagg

no luck yet


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## luciferschild

i snapped some shots of the pcb, would anyone out here in marshall land be willing to trace out the schematic? im trying to find the negative feedback for presence and resonance controls. would be nice to know if c30 is the bright cap also.


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## luciferschild

got a pencil sketch done up, will try figure out a way to computerize it when i get a chance. many frustrations tracing this board - looks as if they have gone out of their way make this difficult. like covering traces with components. curious about the 18k slope resistor, 10k mid pot and 0.047uF tonestack caps as well as the different approach to the tone shift. anyone know if those yellow caps are polyester or polypropylene?


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## slagg

Awesome ! Someone needed to do this. Is c30 the Bright cap?If so it will be the first thing to mod.


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## luciferschild

Im pretty sure c30 is a treble peaker, c32 is the bright cap i believe. it sits across the clean volume pot.
I just measured the output tx impedence as well.
My results - applied 14.6vac to the primary, measured 0.310vac across 16ohm secondary.
14.6/.310=47.1 x 47.1 = 2218 x 16 = 35.5K!
Most interesting


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## slagg

wow 1000pf no wonder its so bright


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## luciferschild

This is what i scrawled down for that part of the clean channel. Looks like c30 might be part of the tone stack even... not too sure. Is 27k a common for a slope resistor ? I may have traced incorrectly, there is so many traces hidden under components it makes life difficult. Don’t mind the 500k pot; I assumed I could exploit its value to beef up the clean channel gain but it doesn’t sound good at all. I’ll find some time soon to take her apart again, I missed the tone too much I put the board back in haha. Jj ecc803s in v1 sounds best to my ears. Tried jj ecc83s, nos Philips 12ax7, ruby high gain 12ax7, Tung sol 12ax7s and a Jj ecc81. I found the Tung sol gold pin to sound the meanest for high gain. Way up in treble territory though! And the 81 best to tame the beast. Couldn’t find any of my jj ecc83s’ to sound as good as the marshal branded one in v2. Also even a new EH 12au7 couldn’t match the stock one either. 
Might try the au7 in v1 next


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## slagg

thinking of removing the bright cap to see if it will take pedals ??


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## Miotch

Man alive. Took mine apart and inspected it today at lunch and put it back together. If anyone figures out for sure what the bright cap is, post it. No luck finding schematic for this model yet. Seems well built at least.


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## slagg

Way well built ! I lifted one side of the bright cap(c32)1000pf.It sounded dull and lifeless.I would have tried another value but nothing on hand.I did on the other hand ran a patch cable in the loop that someone suggested.Wow it did make a difference.The highs are less raspy and a bit more musical.I like it way more this way.


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## Miotch

FYI: I got this from a guy on Strat Talk that is really good with amps:

_"C31 it is. [EDIT: He meant C32 it turns out]
But you can´t just snip it and it is only for the normal channel active (preset tonestack - hard wired, non adjustable)._"

I'm gonna try a patch cable right now.


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## Miotch

Ignore c31. Just noticed he edited it to c32. Typo I reckon.


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## slagg

Patch cable is a small change,but it does smooth it out a bit


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## Miotch

I think I need to suck it up and buy a good efficient low-watt speaker. I have an old 12" of unknown wattage from an old Peavey amp in the cab now. Only 16-watt I have. 
I tried switching the orange for white wire (I did not switch the orange and black ones on the board first) and plugged it into 8-ohm cab. It worked, but had about half the volume of before.


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## luciferschild

EDIT - no transformer problems. I had the ot primary windings hooked up back to front


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## slagg

anybody confirm the white wire to be 8 ohm on the OT ?


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## Miotch

I pulled off the orange wire and put on the white one and hooked it up to 8 ohm cab. Volume about a third what I expected. So I put it back.


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## slagg

Thanks,I'm thinking it is not a 8 ohm tap.If it was I think Marshall would have utilized it.


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## Miotch

Yeah, I guess they might save 12 cents by just putting in one jack. But I didn't reverse the black and orange wires as Mavrim did. But I don't see that making any real difference as far as amount of signal to speaker goes.


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## slagg

Low output= mismatch
I have a Vox ac4 that calls for 16 ohm but is twice as loud at 8 ohm.


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## Miotch

And no problems?? I'm kind of wondering how much damage could I really do to a one-watt amp trying an 8 ohm speaker. But I love the baby amp so much I'd hate to hurt it


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## hugorodrig

Hi, is the schematic anywhere to be found?
I want to add presence and resonance controls, so I need to find the NFB resistor. Also want to reduce the compression a bit. May eventually also make a switcheable SIR #34 mod on it (done it already on a JCM1H and it sounds absolutely amazing).


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## slagg

Miotch said:


> And no problems?? I'm kind of wondering how much damage could I really do to a one-watt amp trying an 8 ohm speaker. But I love the baby amp so much I'd hate to hurt it


No problems at all.


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## Miotch

I tried it and didn't notice any increase in volume. Maybe a bit of a decrease, but I normally have it on a single 12" and went to a 4x10 8-ohm cab. What's your experience with it in volume difference, if any, between 8 and 16 ohm cab ??


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## slagg

It loses volume at 8 ohm.This tells me the "mismatch" is bad. I don't think the OT can handle it for long. It will most likely overheat.


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## Sniper

First post. And I'm resurrecting this topic because of sheer usefulness and awesomeness.


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## Miotch

Sniper said:


> First post. And I'm resurrecting this topic because of sheer usefulness and awesomeness.



Agree. I have since acquired a 2x12 cab with WGS 30-watt Reaper and 60-watt Veteran 30 in it. Sounds fantastic and pumps out a lot for 1 watt.


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## Purplestrat

Any confirmation on the right call? Any other time mods anyone has tried?


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## Purplestrat

Also any reviews on trying different power tubes?


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## zizyphus

Hey! 
First time poster here, long time lurker
This is an awesome thread, so I’m resurrecting it
It looks C30 is the bright cap to me, but some of you have said it’s actually C32? Anyone know for sure that we’re talking about the same schematic (is the one in the photo earlier in this thread)


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## zizyphus

Hey all

I removed C32, and it worked beautifully! C32is the bright cap.


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## EC Strat

slagg said:


> Awesome ! Someone needed to do this. Is c30 the Bright cap?If so it will be the first thing


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## EC Strat

.


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## Purplestrat

zizyphus said:


> Hey all
> 
> I removed C32, and it worked beautifully! C32is the bright cap.



Can you give a little more detail on how it effected the sound at different volumes?


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## ampmadscientist

Miotch said:


> Agree. I have since acquired a 2x12 cab with WGS 30-watt Reaper and 60-watt Veteran 30 in it. Sounds fantastic and pumps out a lot for 1 watt.



Well obviously you need a schematic.
But you run into trouble here because there is a micro-controller with proprietary software operating the amp functions and relays. 
It would take quite a bit of time to trace all through that...
The idea is to make an amp that can't be copied or serviced (surprise) which makes it quite a bit harder to modify.


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## Edward Pentney

Had my DSL1 for a few weeks but really struggling with the aggressive high end on the amp, even when plugged into a 12 inch speaker cab. Still very bright. Not sure if this has been answered in the forum yet, but is there a mod that can be done to reduce the high end ?


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## paul-e-mann

Has anybody figured out how to make these amps sound more open and not so scooped?


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## DonP

Cool thread - some good info.

FWIW, I agree the clean chanel is sort of Fendery bright, but that's my only "issue" (if it is an issue - I'm still new to the amp).

I'd like to have more than a 16 ohm impedance - like 2 16's (for 8 ohms).


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## Rocketman

Just saying "Hi" to everyone here on Marshall Forum. A new Marshall DSL1cr owner here, and a new member of the forum.


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## Rocketman

Well, it's been 10 days and no one has said "Hi" back at me, so I guess everyone involved in this DSL1 discussion has tried these mods and has Blown up their amp. 
Just kidding....I am just looking to see if anyone has any updates on the 8 ohm / 16 ohm mod, ( has anyone definitively traced out what the white wire really is? ) 
Any also a small amount of interest in knowing if C32 is the bright cap. I don't think it is something I would ever change out, but never say never.
Just lookin' for any new updates or new info.

Thanks, to everyone here who contributed to this thread, very good info!


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## Micky

Rocketman said:


> Well, it's been 10 days and no one has said "Hi" back at me, so I guess everyone involved in this DSL1 discussion has tried these mods and has Blown up their amp.
> Just kidding....I am just looking to see if anyone has any updates on the 8 ohm / 16 ohm mod, ( has anyone definitively traced out what the white wire really is? )
> Any also a small amount of interest in knowing if C32 is the bright cap. I don't think it is something I would ever change out, but never say never.
> Just lookin' for any new updates or new info.
> 
> Thanks, to everyone here who contributed to this thread, very good info!


Should have put your 1st post in the Introductions sub-forum. Thats where members here expect to see them...


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## Rocketman

Micky said:


> Should have put your 1st post in the Introductions sub-forum. Thats where members here expect to see them...



Well hello to you too Micky. 
Man,... the ole Introductions sub-forum, that's great. 
I'm not much of an expert on forums, forum etiquette, or procedures. 
Matter of fact, I don't know jack about them. 
I'm a pretty low keyed guy. I don't have any airs about me.

What I know about and understand is electricity and basic electronics. I came here to increase my knowledge about the new DSL1 amps and possibly share some of the things that I have learned and pondered about this amp,
( at least the combo version of it anyway, which is the version I own ).

Micky, Thank you very much for replying back to me, and have a great evening!


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## Rusty Strings

Awesome thread. Thanks !!!

My DSL1CR is not overly bright on the clean/classic nor on the ultra gain channel. I use the stock speaker eight15 and the combo can get really bassy if needed, I usually have the treble around noon, full mids, bass less than noon.
I even thought of finding a less bassy 8 inch guitar speaker, but what are the alternatives there ? I only found celestion super 8 (same as eight15?), Eminence Patriot 820H and the WGS G8C(the alnico version costs) but the latter 2 i'm not sure if there is a 16ohm version. 
Anyway, I run the dsl1cr in the 0.1w mode though. The barcode reads 11-19.
The sound is really full and so good, so swapping the speaker for another 8 incher aint really essential for me. Would be interesting to know if anyone tried to cram 10 inch speaker in the dsl1c combo, a lot more 10"s to select from.
The compression does not feel over the top to me, I used to think, my DSL20HR (with barcode 12-17) on the ultra gain channel compressed more. Repaired 2x and in the end I had to return the head for refund. 

This Marshall DSL1CR is proving to be a little gem, I hope its reliability will stand the test of time.

CHEERS


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## Micky

Rocketman said:


> Well hello to you too Micky.
> Man,... the ole Introductions sub-forum, that's great.
> I'm not much of an expert on forums, forum etiquette, or procedures.
> Matter of fact, I don't know jack about them.
> I'm a pretty low keyed guy. I don't have any airs about me.
> 
> What I know about and understand is electricity and basic electronics. I came here to increase my knowledge about the new DSL1 amps and possibly share some of the things that I have learned and pondered about this amp,
> ( at least the combo version of it anyway, which is the version I own ).
> 
> Micky, Thank you very much for replying back to me, and have a great evening!


Good to see you here!


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## Rocketman

Micky said:


> Good to see you here!


Hey thanks, glad to be here.


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## tce63

Rocketman said:


> Hey thanks, glad to be here.



 to the forum, Cheers


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## Rocketman

Rusty Strings said:


> Awesome thread. Thanks !!!
> 
> My DSL1CR is not overly bright on the clean/classic nor on the ultra gain channel. I use the stock speaker eight15 and the combo can get really bassy if needed, I usually have the treble around noon, full mids, bass less than noon.
> I even thought of finding a less bassy 8 inch guitar speaker, but what are the alternatives there ? I only found celestion super 8 (same as eight15?), Eminence Patriot 820H and the WGS G8C(the alnico version costs) but the latter 2 i'm not sure if there is a 16ohm version.
> Anyway, I run the dsl1cr in the 0.1w mode though. The barcode reads 11-19.
> The sound is really full and so good, so swapping the speaker for another 8 incher aint really essential for me. Would be interesting to know if anyone tried to cram 10 inch speaker in the dsl1c combo, a lot more 10"s to select from.
> The compression does not feel over the top to me, I used to think, my DSL20HR (with barcode 12-17) on the ultra gain channel compressed more. Repaired 2x and in the end I had to return the head for refund.
> 
> This Marshall DSL1CR is proving to be a little gem, I hope its reliability will stand the test of time.
> 
> CHEERS



Great post!
I too have the DSL1CR and I don't find it to be overly bright on either channel, at least to my ears anyway.
(stock speaker, with very few hours on it).
I have no idea who here owns the head unit and who owns the combo, but is it possible that there could be slight design differences between the two units, or possibly just that the stock Celestion eight 15 speaker just sounds good and well balanced in the combo unit?

A show of hands from the forum members on who owns which unit (Head vs Combo) and also if they think it is too bright for them "might" be interesting to know. 

Of course I realize that everything lies in the "ear" of the beholder.


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## Rocketman

tce63 said:


> to the forum, Cheers



thank you


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## DonP

Rocketman said:


> Great post!
> I too have the DSL1CR and I don't find it to be overly bright on either channel, at least to my ears anyway.
> (stock speaker, with very few hours on it).
> I have no idea who here owns the head unit and who owns the combo, but is it possible that there could be slight design differences between the two units, or possibly just that the stock Celestion eight 15 speaker just sounds good and well balanced in the combo unit?
> 
> A show of hands from the forum members on who owns which unit (Head vs Combo) and also if they think it is too bright for them "might" be interesting to know.
> 
> Of course I realize that everything lies in the "ear" of the beholder.



I have the DSL1HR head. I'm currently using a cheap Hartke GH410A 4x10 cab I bought used and it sounds great. I'll have to pull the back to see if the speakers might have been upgraded or if they are the cheap ones these come with.

I have no problems with the tone at all. This head is the perfect heavy metal / thrash metal head I've been wanting since picking up the guitar 35 years ago. I love playing it.

As such, I don't have a huge desire to mod. Having two speaker outputs and a choice of 16 or 8 ohms would be nice, but I'd rather play then mess with it.


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## DonP

A month later and still loving this amp with no modifications needed IMO. The cheap Hartke 4x10 seems to be a perfect match to me.

First I explored the high gain settings with a JB Super Distortion or X2N loaded axe. Loved it.

Then I tried lower distortion tones like early AC/DC. Had no issues there either.

Then I dropped all the way down to single coil tones with a Strat. Don't laugh, some old Pat Benatar tunes. I think Neil is a great guitarist. The DSL1HR did a great job with those tones as well.

No issues with either the clean or the distortion channel.

If I had to pick a desert island amp, this would be the one for me.


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## Ceerce

about DSL1HR...
I tweaked my brother's (my old)amp for fun and test.
C32 is treble cap, seems affect with green channel only, it will take pedals much better without it.
C5 seems to be coupling cap for "red" channel. 4,7nF ? from factory.
C9 seems to be red channels treble peaker. 1,5nF ? from factory.

On "RED"
Signal goes input --> V1B --> V1A --> V2B --> V2A . V2B was cold clipper, with 8k2 ? cathode resistor.
On "GREEN" it goes input --> V1B --> V2A...
A and B could be B and A but you get the idea.
I'll add picture about my 'test bed', there is few other tweaks in present... Plate resistor, input grid stopper, bypass caps, smaller 1st coupling cap etc. (red&brown cables are going to cathode switches for testing purpose)


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## Rocketman

Ceerce said:


> about DSL1HR...
> I tweaked my brother's (my old)amp for fun and test.
> C32 is treble cap, seems affect with green channel only, it will take pedals much better without it.
> C5 seems to be coupling cap for "red" channel. 4,7nF ? from factory.
> C9 seems to be red channels treble peaker. 1,5nF ? from factory.
> 
> On "RED"
> Signal goes input --> V1B --> V1A --> V2B --> V2A . V2B was cold clipper, with 8k2 ? cathode resistor.
> On "GREEN" it goes input --> V1B --> V2A...
> A and B could be B and A but you get the idea.
> I'll add picture about my 'test bed', there is few other tweaks in present... Plate resistor, input grid stopper, bypass caps, smaller 1st coupling cap etc. (red&brown cables are going to cathode switches for testing purpose)
> 
> 
> View attachment 70991



Great post and pic! Seems like you have been busy with that amp. 
Just out of curiosity, did you remove the C32 cap or replace it with another value?


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## Rocketman

Rocketman said:


> Great post and pic! Seems like you have been busy with that amp.
> Just out of curiosity, did you remove the C32 cap or replace it with another value?



Also, is your brothers amp the "2018 Vietnam made version" of this amp, or the older model?
Thanks


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## Gunner64

It says 2018 Vietnam version in the title. I doubt it's an older one..


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## jaropda

Hello ! 
How could the ultra gain channel be modified so that the sound did not have as much compression?
I have tried changing 12AU7 and 12BH7A valves in v1 v2 the gain decreases but the compression persists when you increase the volume gain. 
With the changes of values in c5 and c9 of capacitors, is there a change in the tone of the ultra gain channel?

great thread !!
thank you very much


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## Ceerce

Amp is "vietnam" version, pcb says y17w48. 

In that amp, i moved cold clipper stage from 3rd to 2nd stage, more traditional place in my opinion. Changed C5 to smaller value,it did help RED channel, and changed C9 to smaller value, for less high end. Added switch for cathode resistor(2nd stage), 1.8k / 10k / 33k. 1.8k is bypassed also with cap if needed. with 1.8k cathode resistor it sounded like different amp. 33k for more compress, SLO style CC.

First stage: switch for warm / middle(+bigger cap) / cold-ish bias , and plate resistor from 100k --> 220k. 

it will take pedals much better, and cleans with more low end. i did add socket for C4, .022 originally, i will test more subs for it, and will test sound with modern hi-gain pedals, like clones of revv g2,g3,g4 etc. 



Rocketman said:


> Great post and pic! Seems like you have been busy with that amp.
> Just out of curiosity, did you remove the C32 cap or replace it with another value?



I did add socket for C32. I tried and will try more subs for C32, IMO: better cleans with smaller cap, but pedals did sound harsh , so i did leave it empty for now. it had 0.68uF cap for 1st stage, i did add 2.2uF with 0.68uF, and cleans did get more lows.

I did also try cathode bypass 10uF cap for 4th stage, it had none originally... greens channel did get more dirt at higher gains, but it affected also to red channel, i believe that PI and FX loop didn't stand increased gain, those are solidstates. Maybe interstage dividers could be tweaked.... changing bias of 4th stage did not do much.

I did tweak this amp just for fun and curiosity, it is still "underconstruction". I have to wait my brother to visit and evaluate different mods...after all, it's his amp 

Goal was to improve tolerance to pedals, and less "icy" ultragain sound.


*Btw. If you are on ultragain / RED channel and have bass,middle at 12o'clock, then turn treble pot to full off, how does your amp change sound??? Use moderate gain and volume. *

That vietnamese DSL1 in my garage has weird behavior with treble off, modded or not... it first cut treble as it should but at zero, it regains treble, and change sound to something else, more mids, really different sounding DSL1 with treble off.


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## guitar1580

Great thread here. I'm enjoying seeing the different experiments you guys are trying.

For the record, I have the head version of the amp, and have tried it through a couple of different single 12 Celestions. I also find the clean channel very bright & shrill. It has a trebly quality that reminds me of a Marshall acoustic amp that I tried out around 15 yrs ago. I liked it, but the highs were a little screechy & unnatural and I went with a Fender Acoustasonic Jr. instead. 

Seems that I can dial the treble pot back and get the DSL1 sounding pretty good, but I couldn't imagine playing my vintage Tele through it. Would be like a dog whistle. Sounds great with my G&L Strats. I have a feeling that my older Les Paul Standard is going to sound great through it.

I haven't had it very long. The patch cord through the loop sounds interesting. I'm going to give that a try.


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## acevh00

Interesting thread for me, having bought the DSL1 HR two days ago.
With my 1960A 4x12, the classic channel is really beautiful, with great bass and treble, wide range of frequencies and a lot of presence (as every Marshall I had in the past has, anyway) and it seems my JCM2000 DSL100 of many years ago (I sold it only because it was a tube fryier, but the sound was great).
Instead, the red channel seems to be the distortion of a poor pedal, I'd say a BOSS: poor treble and presence, with a tone totally swollen, without details.
I think I first have to replace the tubes, because the Fender Frontman combo 15w of my daughter has a more credible gain with his transistors.
Maybe with the volume cranked up it could be much better, but, at home, a 1 watt must sound good at any volume level, otherwise there is something wrong.

I think this little Marshall could like a mod for the red channel, to open the sound and give presence and details to the sound, because actually the green channel is perfect, but the red is like to put a mattress on the cones, not a simple blanket...


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## Timmy51

My DSL 5cr is the exact same way. The green channel is beautiful but the red channel sounds like someone put a pillow over it and the distortion isn’t good at all. Sounds like a really cheap distortion box. Let me know if you find a solution.



acevh00 said:


> Interesting thread for me, having bought the DSL1 HR two days ago.
> With my 1960A 4x12, the classic channel is really beautiful, with great bass and treble, wide range of frequencies and a lot of presence (as every Marshall I had in the past has, anyway) and it seems my JCM2000 DSL100 of many years ago (I sold it only because it was a tube fryier, but the sound was great).
> Instead, the red channel seems to be the distortion of a poor pedal, I'd say a BOSS: poor treble and presence, with a tone totally swollen, without details.
> I think I first have to replace the tubes, because the Fender Frontman combo 15w of my daughter has a more credible gain with his transistors.
> Maybe with the volume cranked up it could be much better, but, at home, a 1 watt must sound good at any volume level, otherwise there is something wrong.
> 
> I think this little Marshall could like a mod for the red channel, to open the sound and give presence and details to the sound, because actually the green channel is perfect, but the red is like to put a mattress on the cones, not a simple blanket...


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## acevh00

Timmy51 said:


> My DSL 5cr is the exact same way. The green channel is beautiful but the red channel sounds like someone put a pillow over it and the distortion isn’t good at all. Sounds like a really cheap distortion box. Let me know if you find a solution.


I FOUND the solution.........!!!!!!!
Victory !!!! 
Now my DSL1 is roaring with the tone of the 100w at bedroom levels, with brilliant treble, powerful medium and clear bass tones, with the 1960A 4x12.
I decided to pull out ALL the three tubes and put 1 TAD selected WA 12ax7 in V1 (a balanced one), a TT 12ax7 in V2 (a very good chinese selected) and a Tung-Sol 12AU7 W 6189
that I've never tried before... and WOW ...!!!
I have now a completely different amp, incredible!
I don't understand just one thing: I have various (and had many in the past) tube amp heads and I'm used to tone differences changing tubes, specially the pre ones. But I never found such a gap. Now the amp is singing with great dynamic (as a Marshall has to do). Before, it was a bloated compressed thing, maybe good only for Venom covers.
Actually I'm asking myself what f.....g tubes Marshall is putting inside these little jewels. It isn't a smart choice to save money on tubes quality.

An advice..: buy this little head, because it's superb, but change immediately the tubes!!!
The last thing: I made also a test, installing three worn out Marshall tubes 12ax7 of my old JCM2000 DSL100 (with some years of use) that have lost much of the original power: the result was a great sound, without screaming gain but detailed and dynamic... still 10 times better than with the original tubes!!!!!


----------



## Rocketman

acevh00 said:


> I FOUND the solution.........!!!!!!!
> Victory !!!!
> Now my DSL1 is roaring with the tone of the 100w at bedroom levels, with brilliant treble, powerful medium and clear bass tones, with the 1960A 4x12.
> I decided to pull out ALL the three tubes and put 1 TAD selected WA 12ax7 in V1 (a balanced one), a TT 12ax7 in V2 (a very good chinese selected) and a Tung-Sol 12AU7 W 6189
> that I've never tried before... and WOW ...!!!
> I have now a completely different amp, incredible!
> I don't understand just one thing: I have various (and had many in the past) tube amp heads and I'm used to tone differences changing tubes, specially the pre ones. But I never found such a gap. Now the amp is singing with great dynamic (as a Marshall has to do). Before, it was a bloated compressed thing, maybe good only for Venom covers.
> Actually I'm asking myself what f.....g tubes Marshall is putting inside these little jewels. It isn't a smart choice to save money on tubes quality.
> 
> An advice..: buy this little head, because it's superb, but change immediately the tubes!!!
> The last thing: I made also a test, installing three worn out Marshall tubes 12ax7 of my old JCM2000 DSL100 (with some years of use) that have lost much of the original power: the result was a great sound, without screaming gain but detailed and dynamic... still 10 times better than with the original tubes!!!!!




Fantastic! UFO..1980!, 1980!...Commander Ed Straker!!! Love the show and I really liked your post, thanks


----------



## acevh00

Rocketman said:


> Fantastic! UFO..1980!, 1980!...Commander Ed Straker!!! Love the show and I really liked your post, thanks


...


----------



## acevh00

My DSL1 is really singing now.... But I tried other changes with other tubes, arriving to a conclusion.
The tone of this little head is very sensible to the tubes you use, specially of preamp, probably because of having only three tubes: so, changing just one means having modified 33% (or more... the power tube has less impact on the tone) of the potential.
I had about a dozen of tube amps until now (currently are three), from 1 to 100W, and I change often my tubes, with alternate luck, and often with nice improvement of sound, but this one is the most sensible overall.
The DSL1 reacts very well also with old Svetlana, moden chinese TT and Shuguang (selected), Mullard and Tung-Sol. But I discovered that the "plus" is the TAD selected WA in V1.
And, apart from the original crappy tubes. the less brilliant results are obtained by JJ, EH and Sovtek.
The JJ are too dark and compressed for this amp, that needs "air" in the gain channel. EH and Sovek are too fizzy and not dynamic.
I hope these advices can help someone with the same amp head.


----------



## Rocketman

acevh00 said:


> My DSL1 is really singing now.... But I tried other changes with other tubes, arriving to a conclusion.
> The tone of this little head is very sensible to the tubes you use, specially of preamp, probably because of having only three tubes: so, changing just one means having modified 33% (or more... the power tube has less impact on the tone) of the potential.
> I had about a dozen of tube amps until now (currently are three), from 1 to 100W, and I change often my tubes, with alternate luck, and often with nice improvement of sound, but this one is the most sensible overall.
> The DSL1 reacts very well also with old Svetlana, moden chinese TT and Shuguang (selected), Mullard and Tung-Sol. But I discovered that the "plus" is the TAD selected WA in V1.
> And, apart from the original crappy tubes. the less brilliant results are obtained by JJ, EH and Sovtek.
> The JJ are too dark and compressed for this amp, that needs "air" in the gain channel. EH and Sovek are too fizzy and not dynamic.
> I hope these advices can help someone with the same amp head.




Thanks for all of the information. Good quality post.
I hope this didn't take away too much of your time from making movies at the studio. wink, wink.


----------



## acevh00

Rocketman said:


> Thanks for all of the information. Good quality post.
> I hope this didn't take away too much of your time from making movies at the studio. wink, wink.


.......



Off topic... I know.... please excuse me....!


----------



## Rocketman

Ah, I see those are a set of the Svetlana tubes. I bet they sound great. Very nice!


----------



## Ceerce

acevh00:

Do you have original tubes still around=? Mind you check markings about those if possible. 

My former DSL1 had one 12ax7 chinese?-tube, with white text. one 12ax7 with red print, like jj, and 12au7 was with red markings. i'll add marshall codes about those when i remember. 
Curious to know if others DSL1 have 'random' tubes in. 

I did also change all tubes first. No such dramatic change as yours, i believe, in fact tried many different 12AX7 in it... JJ,sovtek,EH,TAD, JJ MG, TAD 7025 etc.. I did had only one 12AU7, JJ, i did leave it in.

Also i checked bias with JJ 12AU7, it was a bit high, i did leave it as it was.( i did write it up, i'll try to search numbers)


----------



## acevh00

Ceerce said:


> acevh00:
> 
> Do you have original tubes still around=? Mind you check markings about those if possible.
> 
> My former DSL1 had one 12ax7 chinese?-tube, with white text. one 12ax7 with red print, like jj, and 12au7 was with red markings. i'll add marshall codes about those when i remember.
> Curious to know if others DSL1 have 'random' tubes in.
> 
> I did also change all tubes first. No such dramatic change as yours, i believe, in fact tried many different 12AX7 in it... JJ,sovtek,EH,TAD, JJ MG, TAD 7025 etc.. I did had only one 12AU7, JJ, i did leave it in.
> 
> Also i checked bias with JJ 12AU7, it was a bit high, i did leave it as it was.( i did write it up, i'll try to search numbers)


My tubes were one with white Marshall markings, one red and one gold.
I can't be more precise... all finished in the trash can with great satisfaction.


----------



## Gorguts

Hello, does anyone know where I could find the nfb loop on this Amp to add a presence and resonance control?


----------



## Iron1

acevh00 said:


> An advice..: buy this little head, because it's superb, but change immediately the tubes!!!





Ceerce said:


> acevh00:
> 
> Do you have original tubes still around=? Mind you check markings about those if possible.



I could have sworn I read somewhere that these are shipping with JJ tubes now, and mine doesn't at all sound like what Ace is describing. Could it be Marshall made a change?



Gorguts said:


> Hello, does anyone know where I could find the nfb loop on this Amp to add a presence and resonance control?



I'd love to be able to add a resonance as well, anyone have insight to that one?


----------



## StraightToTheBar

So.. to sum up: C32 is the bright cap in these new dsl's? As in to perform the bright cap mod (on both channels)? Or is it C5? C9? pfew


----------



## Dogs of Doom

Miotch said:


> And no problems?? I'm kind of wondering how much damage could I really do to a one-watt amp trying an 8 ohm speaker. But I love the baby amp so much I'd hate to hurt it


I had stated a long time ago, in another DSL1 thread, that chances of issues using an 8 ohm speaker are pretty much zero...

I had Santiago weigh in & he agreed, but, the guy asking in the thread, didn't want to believe us...


----------



## Dogs of Doom

This is regarding the original 50th Ann model:



santiall said:


> i forgot the exact labeling on the speaker output but a load of 8 ohms is specified as minimum output impedance. You can safely connect an 8ohms cabinet and still enjoy 1W of power safely and without mismatch.
> 
> The reason of having a single speaker output is to allow using the amplifier without a speaker connected at all for recording direct through the line output and retaining the 0.1W mode. The internal transformer impedance is chosen to compensate all this helped by the low power and the fact that the output tubes are triodes.



This is regarding the new one. You can follow either of these posts back (for context), by clicking on the "said w/ arrow up"



santiall said:


> I'm afraid I don't 100% know... The current DSL series were started while I was still there but I'm sure the design was changed after I left. It's got a ECC82 push pull output and probably it has a solid state phase inverter but that doesn't matter. In any case I don't see any problem using an 8ohm cabinet with that amp, I'm sure it can tolerate the mismatch without any issues.
> 
> The mismatches aren't a big deal, the real problem with tube amps are intermittent loads like a faulty jack vibrating and not making proper contact, a speaker cable with soldering issues or continuity problems and so on.



I spent quite a bit of time asking him about my 1 watt JVM. He told me that, in essence, it's only 1 watt. There's not much you can do. Low power amp's like that, are very robust, because of the small amount of power produced.

Even Steve D, when talking about the Class 5 amp, said that, he spent many hours, plugged in, unplugged (still running it) & w/ all that, he never had any problems w/ the amp, during R&D.

These guys during R&D put it through the ringer, doing all the things they tell us not to do.

Santiago has also stated, that mismatching is overblown, even in larger amp's.



santiall said:


> It says "MAY" not "WILL". The 16+8ohm configuration is a perfect match if connected to the right outputs as described elsewhere.
> 
> Don't worry either about the output transformer myth, there is no problem with mismatching loads in any amps or splitting the load as long as there are available outputs, this is not any JVM exclusive feature, it is just plain physics. As long as there is a load connected properly you'll be safe, danger comes with intermittent connected loads, poor cabling, etc, but a mismatch by itself won't cause any harm


----------



## Marco77

acevh00 said:


> I FOUND the solution.........!!!!!!!
> Victory !!!!
> Now my DSL1 is roaring with the tone of the 100w at bedroom levels, with brilliant treble, powerful medium and clear bass tones, with the 1960A 4x12.
> I decided to pull out ALL the three tubes and put 1 TAD selected WA 12ax7 in V1 (a balanced one), a TT 12ax7 in V2 (a very good chinese selected) and a Tung-Sol 12AU7 W 6189
> that I've never tried before... and WOW ...!!!
> I have now a completely different amp, incredible!
> I don't understand just one thing: I have various (and had many in the past) tube amp heads and I'm used to tone differences changing tubes, specially the pre ones. But I never found such a gap. Now the amp is singing with great dynamic (as a Marshall has to do). Before, it was a bloated compressed thing, maybe good only for Venom covers.
> Actually I'm asking myself what f.....g tubes Marshall is putting inside these little jewels. It isn't a smart choice to save money on tubes quality.
> 
> An advice..: buy this little head, because it's superb, but change immediately the tubes!!!
> The last thing: I made also a test, installing three worn out Marshall tubes 12ax7 of my old JCM2000 DSL100 (with some years of use) that have lost much of the original power: the result was a great sound, without screaming gain but detailed and dynamic... still 10 times better than with the original tubes!!!!!



There is a way to calibrate the bias (e.g. a trimmer)? Or you have just to replace some resistors.
Thanks


----------



## rjohns1

Use an ohm meter and see if the cap is connected to the pins of the gain pot. That will definitively tell you if it is the bright cap. It would be connected to one outer pin, and the middle pin.


----------



## leandro vivian

Hi everyone. I get the dsl1 schematic, and make some mods.


In gain mode, I replaced some values based on jvm1 and installed a switch to change capacitor C23 and activate C24. In tonestack, I used another key to change the C12 from 270pf (orange style) and 470pf (soldano style). The best mod is the negative feedback, presence and deep controls and the power compresses much less. lose a little volume but it's worth it.


----------



## leandro vivian

My works.


----------



## Sustainium

leandro vivian said:


> My works.


But how does it SOUND?


----------



## leandro vivian

Sustainium said:


> But how does it SOUND?


Hi body!
well...in first, sorry for my inglish, im brazilian guy so....
For metal sounds great, i tried some values and cobinations, and this setup gounds better.. the boost mod, works in two chanel, the clean chanel gives more opitions too. i used 70/80 celestion speakers, 2x12 16 ohms, and bill lawrence pickups.
Try boost with sd-1 and orange mod sounds like hell!!!!
I love experimenting with different combinations, I think I'll never stop trying to fix what's not broken.


----------



## Sustainium

leandro vivian said:


> Hi body!
> well...in first, sorry for my inglish, im brazilian guy so....
> For metal sounds great, i tried some values and cobinations, and this setup gounds better.. the boost mod, works in two chanel, the clean chanel gives more opitions too. i used 70/80 celestion speakers, 2x12 16 ohms, and bill lawrence pickups.
> Try boost with sd-1 and orange mod sounds like hell!!!!
> I love experimenting with different combinations, I think I'll never stop trying to fix what's not broken.


Thanks for the reply and your English is easy to understand!


----------



## Rocketman

leandro vivian said:


> Hi everyone. I get the dsl1 schematic, and make some mods.
> 
> 
> In gain mode, I replaced some values based on jvm1 and installed a switch to change capacitor C23 and activate C24. In tonestack, I used another key to change the C12 from 270pf (orange style) and 470pf (soldano style). The best mod is the negative feedback, presence and deep controls and the power compresses much less. lose a little volume but it's worth it.



Hi, Great posts. I was wondering where did you find the Schematics, and could you provide a link to the site where you found them?
Thank you very much.


----------



## leandro vivian

Hello. I tried to send an email to Marshall here in Brazil, but I was told to seek authorized assistance here. So I have a friend who lives in Canada, he sent an email to Marshall asking for the scheme to make a repair and Marshall sent it the scheme for him. simple like that!


----------



## Rocketman

leandro vivian said:


> Hello. I tried to send an email to Marshall here in Brazil, but I was told to seek authorized assistance here. So I have a friend who lives in Canada, he sent an email to Marshall asking for the scheme to make a repair and Marshall sent it the scheme for him. simple like that!



Well very cool. Thanks for the update.


----------



## acevh00

Marco77 said:


> There is a way to calibrate the bias (e.g. a trimmer)? Or you have just to replace some resistors.
> Thanks


You don' t need to set the bias: it has only one power tube...


----------



## leandro vivian

One more mod. Master volume for the clean chanel, very easy to do it. VR= 1M linear. i forgot to said. cut off the R17(47k).


----------



## leandro vivian

hi. I did a new mod, this time I use the ENGL fireball as inspiration. HIgh gain amps using a high pass filter after the first triode. The RC circuit is C=1.5nf/3nf, changed on key, and R=220K. This filter cut the low frequences started around 470htz to less.this RC filter make the first triode work like a pedal mid booster, like a sd-1, TS9,etc. You can see this filter in ENGL schematic inside the red ball.And I didi a new look for the amp, only need the mini chicken head knobs


----------



## ngetal

leandro vivian said:


> hi. I did a new mod



Impressive work, leandro. Do you happen to have any sound samples comparing your mods?


----------



## tce63

ngetal said:


> Impressive work, leandro. Do you happen to have any sound samples comparing your mods?



 to the forum 

Cheers


----------



## Rocketman

A little off subject but, I was wondering... do two Flying V's taped together make a Flying "W" or a Flying "M" ? .
.
.


----------



## fitz

Hi all, I'm having a new issue with my DSL1HR. 
I've been searching threads for hours and can't quite find something similar.

All of the sudden, my Ultra Gain channel went from the typically described overly bright, to sounding like I slid my whole little micro rig into the closet and shut the door.
I even purchased the ECC823 for V1 to tame the gain, but have not gotten around to putting it in yet.
I was planning a 3 tube swap as everything I have read seems to concur that any tubes are better than the stock ones.

Now I 'm not sure where to start.
Didn't plan on any of the radical mods I've seen, but I have no fear of putting the little bugger under the scalpel either.


----------



## Rocketman

fitz288 said:


> Hi all, I'm having a new issue with my DSL1HR.
> I've been searching threads for hours and can't quite find something similar.
> 
> All of the sudden, my Ultra Gain channel went from the typically described overly bright, to sounding like I slid my whole little micro rig into the closet and shut the door.
> I even purchased the ECC823 for V1 to tame the gain, but have not gotten around to putting it in yet.
> I was planning a 3 tube swap as everything I have read seems to concur that any tubes are better than the stock ones.
> 
> Now I 'm not sure where to start.
> Didn't plan on any of the radical mods I've seen, but I have no fear of putting the little bugger under the scalpel either.


.
1) " Have you tried turning it off and on again? " (the IT Crowd). Sorry, a little humor there.

2) So everything works correctly with the classic gain channel? You have tested that all three tone stack controls are working correctly?
3) If so, knowing that can eliminate some of the potential causes of your problem. ( i.e. a bad tube would "probably" cause problems with the classic gain channel also. ) 
4) Start eliminating the "Simple stuff" first like.... have you tried testing the amp with another guitar, another guitar cable, just to eliminate them from the equation. Are "All" of your connections good? the speaker connections , speaker wire connections on the speaker.

5) Also remove any other hardware from the signal chain (pedals, etc.), Go straight from guitar to amp.

6) Use a careful process of elimination, in a logical sequence, to isolate and eliminate every single thing that you can that could make a difference with the tone/sound. 

Sorry I have no answers for you, just a few suggestions to possibly help you figure out the problem on your own.
p.s. I have no idea why I numbered my sentences. ( I guess just to represent doing diagnostics in a logical sequence.)

Give us an update with more details and any new found knowledge about the problem.


----------



## fitz

Rocketman said:


> .
> 1) " Have you tried turning it off and on again? " (the IT Crowd). Sorry, a little humor there.
> 
> 2) So everything works correctly with the classic gain channel? You have tested that all three tone stack controls are working correctly?
> 3) If so, knowing that can eliminate some of the potential causes of your problem. ( i.e. a bad tube would "probably" cause problems with the classic gain channel also. )
> 4) Start eliminating the "Simple stuff" first like.... have you tried testing the amp with another guitar, another guitar cable, just to eliminate them from the equation. Are "All" of your connections good? the speaker connections , speaker wire connections on the speaker.
> 
> 5) Also remove any other hardware from the signal chain (pedals, etc.), Go straight from guitar to amp.
> 
> 6) Use a careful process of elimination, in a logical sequence, to isolate and eliminate every single thing that you can that could make a difference with the tone/sound.
> 
> Sorry I have no answers for you, just a few suggestions to possibly help you figure out the problem on your own.
> p.s. I have no idea why I numbered my sentences. ( I guess just to represent doing diagnostics in a logical sequence.)
> 
> Give us an update with more details and any new found knowledge about the problem.


I reposted in a new thread:
*DSL1HR Ultra Gain unusually dull*
More info & follow up there, Thanks.


----------



## harry mudd

Hi folks,
after ebaying a DSL1C (not the 50s anniversary - I sold mine in the past)
I swapped the speaker today for a Celestion TF0818 - much improvement tonewise. The sometimes trebly sound is gone and the clean channel does't pierce my ears anymore bass response is much better and this speaker makes this little amp one step bigger.

merry Xmas
H.


----------



## luciferschild

Merry Christmas everyone ! 
hey Leandro, thanks for all your help here, can’t wait to start tinkering with mine. 
Any chance your tech friend has the schematic of the studio classic and studio vintage? I’d be eternally grateful !


----------



## Rocketman

Merry Christmas to All !!! Have a Happy New Year Too!


"keep your damn fingers out of that amp, you don't know what your doing"


----------



## Max Gahne

sorry, late to the thread and posted something redundant. And don't see how to delete a post


----------



## Rocketman

Max Gahne said:


> sorry, late to the thread and posted something redundant. And don't see how to delete a post



That sounds like the story of my life. Hah

Great trick user name by the way. Thumbs up!


----------



## Max Gahne

Rocketman said:


> That sounds like the story of my life. Hah
> 
> Great trick user name by the way. Thumbs up!



Thanks, it's short for Maximus


----------



## leandro vivian

If somebody wish less high treble in dsl, change C11. its 470p, change around 560p,680p or 1nf.
the mininun tension of C11 is 400V.


----------



## Rocketman

leandro vivian said:


> If somebody wish less high treble in dsl, change C11. its 470p, change around 560p,680p or 1nf.
> the mininun tension of C11 is 400V.



Hats off to you Leandro! Over the past few weeks, you and a few others here, have solved and answered a majority of the mysteries and questions about this amp. Great job! Keep the information coming.

Me... I'm just here for the free popcorn.


----------



## Rocketman

HAPPY NEW YEAR TO EVERYONE !!!


----------



## leandro vivian

[QUOTE = "Rocketman, post: 2074446, member: 58207"] Tiremos o chapéu para você Leandro! Nas últimas semanas, você e alguns outros aqui resolveram e responderam à maioria dos mistérios e perguntas sobre este amplificador. Bom trabalho! Continue a transmitir as informações.

Eu ... Estou aqui apenas pela pipoca grátis. [/ QUOTE]
Thanks my friend. I know lots about this dls version, but i speak portuguese, for me its hard to try explain. I used google translate, but sometime looks strange. Happy new year!


----------



## Rocketman

leandro vivian said:


> [QUOTE = "Rocketman, post: 2074446, member: 58207"] Tiremos o chapéu para você Leandro! Nas últimas semanas, você e alguns outros aqui resolveram e responderam à maioria dos mistérios e perguntas sobre este amplificador. Bom trabalho! Continue a transmitir as informações.
> 
> Eu ... Estou aqui apenas pela pipoca grátis. [/ QUOTE]
> Thanks my friend. I know lots about this dls version, but i speak portuguese, for me its hard to try explain. I used google translate, but sometime looks strange. Happy new year!



You do great at explaining things. If a few words come out a little off, or different, don't worry about it. We will figure it out.
Take care, and thanks again for the information you have shared with the forum.


----------



## Snoopy69

Rocketman said:


> A show of hands from the forum members on who owns which unit (Head vs Combo) and also if they think it is too bright for them "might" be interesting to know.



I have the combo. With the classic gain full it sounds right. If you turn it down it's way too bright at 12 o'clock. It's a very clean channel for "classic" gain. I think to me it's a clean channel period. Are people getting gain sounds out of this? There is some power tube breakup but if I put a volume box in the effects loop the output isn't driven hard enough to overdrive and the pre-amp is dead clean for sure. And that's probably why this one doesn't have gain & volume controls, because it's always clean. They've made it be a clean and "sparkly" (yuk to me) channel. It has lots of bass and a great sound though. I broke the speaker in for 2 hours on a transformer before I used it also. So mine pretty much sounding how it was imagined to be. I wouldn't ever change the speaker, there's just nothing better (famous last words, nah I just mean for me personally, but I did look at the Weber site though haha)


----------



## Txdslguy

Any mods to thicken the tones?


----------



## Rocketman

Kinda quiet in here lately.
I'm working on modding one of my flying V 's.
I've installed (1) volume control and (11) tone thickening controls.
What do ya think

?,..... Too much?
"Looking for the tones bruh". "Need more tones!"


----------



## Rocketman

Happy Easter! to everyone who celebrates Easter. Everyone else can still enjoy the chocolate bunnies and peeps.
Stay strong and stay safe, things are getting better.


----------



## guitar1580

Here's a mod that I just did to my DSL1 head that some of you may find useful. My Marshall 1x12 cabinet has a handle on top, and the rubber feet on the head weren't tall enough to clear it, causing the head to bottom out on the handle and sit wobbly. I didn't really want to prop it up on wood blocks which would allow all of the vibration from the cab to transfer to the head.

After searching a little online, I found these nice Peavey rubber feet from parts-express that are just the right size for $5.88 plus shipping. Worked out great, and the head sits well on the cab without hitting the handle. The original ones from the DSL1 were bigger and better than the ones on my Roland Micro Cube travel amp, so I made that swap too. Both practice amps now have bigger and better rubber footing.

https://www.parts-express.com/Peavey-Small-Rubber-Feet-Set-of-4-248-8784


----------



## davidou

Hello Everyone, I am David from France, first I did not understand all technical content regarding DSL1HR electronics / PCB Mods ... , though it was very interesting and I much like the "tone" of the discussion 

I am not satisfied at all with the character of the distortion of this amp (Red Channel) : Whatever the volume the "power chords" sounds really bad to me :/
I like the Green Channel turned up but not possible at home, So I added a Boss OD3 which brings much character (and much drive even at Gain 0 !) but still not fine on mutes, power chords/riffs (someone mentionned it is almost like a bad distortion pedal ==> I agree)
OK this is a Dual Super "LEAD" series but I did not expect it to be just fine on lead solos/blues/arpeggios etc !!! I WANT my guns and roses rythm riffs ! ( as much as possible ...) 

I am on my way to change the 2*ECC83 + 1*ECC81 tubes (Already ordered three of them)
I did not know which to buy so I starded with : 
1x Groove Tubes Premium GT-ECC83-S (certainly V1)
1x TAD JJ ECC83S/12AX7 Tube (certainly V2)
1x TAD JJ 12AU7/ECC82 Tube (V3)

Maybe this will be the same results ... maybe worst, we will see 

I starded to remove the back grid and can see the 3 Tubes .. But I suppose I have to open it up, since the access here is not right. I should do that on my own!
But what would you advise for the tubes removal/install ? It feels like we have to put our fingers on the upper glass itself, and cannot hold the tube from the bottom of it (there are some inamovible rubber circle joints at the bottom of the tube). I am not confident here as you understood.
Sorry I cannot send pictures right, will do this later if needed.
Thank you very much for any help ! Have a good week-end


My "Set" :
Guitar Epiphone Les Paul Ultra with Micros Seymour Duncan SH2/SH4
Amp DSL1HR
Half-Open Cab 10" with Celestion Creamback G10 16Ohms
Boss OD3 Overdrive/Disto


----------



## fitz

davidou said:


> Hello Everyone, I am David from France, first I did not understand all technical content regarding DSL1HR electronics / PCB Mods ... , though it was very interesting and I much like the "tone" of the discussion
> 
> I am not satisfied at all with the character of the distortion of this amp (Red Channel) : Whatever the volume the "power chords" sounds really bad to me :/
> I like the Green Channel turned up but not possible at home, So I added a Boss OD3 which brings much character (and much drive even at Gain 0 !) but still not fine on mutes, power chords/riffs (someone mentionned it is almost like a bad distortion pedal ==> I agree)
> OK this is a Dual Super "LEAD" series but I did not expect it to be just fine on lead solos/blues/arpeggios etc !!! I WANT my guns and roses rythm riffs ! ( as much as possible ...)
> 
> I am on my way to change the 2*ECC83 + 1*ECC81 tubes (Already ordered three of them)
> I did not know which to buy so I starded with :
> 1x Groove Tubes Premium GT-ECC83-S (certainly V1)
> 1x TAD JJ ECC83S/12AX7 Tube (certainly V2)
> 1x TAD JJ 12AU7/ECC82 Tube (V3)
> 
> Maybe this will be the same results ... maybe worst, we will see
> 
> I starded to remove the back grid and can see the 3 Tubes .. But I suppose I have to open it up, since the access here is not right. I should do that on my own!
> But what would you advise for the tubes removal/install ? It feels like we have to put our fingers on the upper glass itself, and cannot hold the tube from the bottom of it (there are some inamovible rubber circle joints at the bottom of the tube). I am not confident here as you understood.
> Sorry I cannot send pictures right, will do this later if needed.
> Thank you very much for any help ! Have a good week-end
> 
> 
> My "Set" :
> Guitar Epiphone Les Paul Ultra with Micros Seymour Duncan SH2/SH4
> Amp DSL1HR
> Half-Open Cab 10" with Celestion Creamback G10 16Ohms
> Boss OD3 Overdrive/Disto


 to the forum.

Yes, just grab ahold of the top part of the tube and pull up while giving it a little wiggle side to side.
They will come out.
The rubber ring is for vibration, it is connected to the chassis and will stay in place.

If you want to lower the gain on the red channel try an ECC823 in V1.
It's like having an ECC82 on red and ECC83 on green.
I have one in my DSL20H.
Good luck and post a reply if you have any problems with your tube swapping.


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## davidou

thank you fitz, sure I will give some feedbacks ! cheers


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## Beartone

What if the DSL1 fits the old Lead12 cab? And 12” speakers can fit in Lead 12. Not suggesting anyone should mod anything but Lead 12 does look a lot like DSL1.


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## fitz

Beartone said:


> What if the DSL1 fits the old Lead12 cab? And 12” speakers can fit in Lead 12. Not suggesting anyone should mod anything but Lead 12 does look a lot like DSL1.


DSL1 heads are a good size match for the Lead12, Lead 15 and MG15 micro stack speaker cabs.
I used to have both heads on my Lead15MS.
And that's a *no* to will a 12" speaker fit in those 10" cabs.
But there are some great upgrades available to the 10" stock speakers.
I just put a pair of VTjrs in my Lead 15 cabs and love the tone.

edit:  to the forum.


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## Beartone

I can fit a 12” in my Lead12. It barely fits. lol Have you ever tried? I have 1984 year, but I figured they were all the same dimensions.


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## fitz

Beartone said:


> I can fit a 12” in my Lead12. Barely but it fits. lol Have you ever tried? I have 1984 year but I figured they were all the sane dimensions.


I looked at it, and would have needed to cut out some of the frame along with the baffle hole.
If you got one to fit, then go for it.
Not sure about the tone of a 12" in that little box, but that's up to you.
I also have a bunch of bigger amps, so if I want loud, I got it.


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## Beartone




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## Beartone




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## Beartone

Sorry for delay on pics I guess jpeg is too big.


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## fitz

Beartone said:


> View attachment 89402


Ah, DSL1 combo / Lead12 combo.
Sorry, I think I didn't understand your original question.
I was thinking head/cabs micro stacks - not the combos
The internal structure of the G15MS cabs I have is a little different.


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## Beartone

Yeah it sounds better than 8” , and I don’t have a 16 ohm 10” laying around. 

The 10” 8 ohm from Lead 12 is now paired in series with another 8 ohm 12” in an extension cab. I do like that combo a lot. 

But it’s nice having 12” for stand alone. If I do buy a 16 ohm 10” speaker it will be a nice low watt one. 

I’m a new member and I haven’t searched the forums. But I’m happy that people are aware of the lead 12 combo as a chassis candidate. I’m guessing the designers of the dsl1 were somewhat inspired by it. They look very similar to
me.


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## Beartone

I apologize, I can see why my original post was misleading. I was going to post pics with rhetorical questions but the jpegs didn’t work. I guess they were to large.

Anyhow it’s delightful.


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## davidou

Hello,
I come arround again, I have received my new tubes
I can easily find the ECC82 Poweramp section one (this is the one behind the 2 oher ones)
but I am not sure regarding ECC83 V1/V2 positions
I post a picture, so please would someone tell me which tube is the V1, and which is the V2 here ?
I suppose the V1 is the Red one, V2 the Grey one, but not sure 
I would like to put for a first try the Groove Tube Premium at V1 position


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## fitz

davidou said:


> Hello,
> I come arround again, I have received my new tubes
> I can easily find the ECC82 Poweramp section one (this is the one behind the 2 oher ones)
> but I am not sure regarding ECC83 V1/V2 positions
> I post a picture, so please would someone tell me which tube is the V1, and which is the V2 here ?
> I suppose the V1 is the Red one, V2 the Grey one, but not sure
> I would like to put for a first try the Groove Tube Premium at V1 position


You are correct. V1 is closest to the input jack, V2 is the middle one.


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## davidou

Well the substitution of the tube is done
Not so easy to push the pin into the socket ... but finally succedeed
And I am more than satisfied with this new configuration !
Much more dynamics and sensitiveness, more balanced, more definition
also the volume seems easier to manage it is not so loud as it used to be
Maybe I will try other configuration since I have now some choice with tubes at home 
Thank you fitz ! Cheers


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## grappo-soda

Hi all!
I’m a bit confused on several opinions that there is too much treble response from this amp. 
Making some guesstimate calculation (using spec sheet on ECC82 and the reported OT winding earlier in this thread), one would expect the transformed source impedance to be ~4ohm, ie less than 16ohm nominal load.
That would imply reduced response for higher frequencies (and also around speaker/cabinet bass resonance) by the typical impedance curve.
Perhaps designer did consider this, but over-compensate the EQ to be overly bright?


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## acevh00

grappo-soda said:


> Hi all!
> I’m a bit confused on several opinions that there is too much treble response from this amp.
> Making some guesstimate calculation (using spec sheet on ECC82 and the reported OT winding earlier in this thread), one would expect the transformed source impedance to be ~4ohm, ie less than 16ohm nominal load.
> That would imply reduced response for higher frequencies (and also around speaker/cabinet bass resonance) by the typical impedance curve.
> Perhaps designer did consider this, but over-compensate the EQ to be overly bright?


Could be a right argument....
I just sold mine (sixth Marshall sold, without being really satisfied). Clean channel very bright, but useful with pedals, and gain channel (despite new high-priced tubes that anyway damped the problem a bit) too dark and dull.


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## grappo-soda

Comparing to other available schematics for DSL amps (ie DSL20) the preamp is very much the same, other than a few decouple caps and some tweaks to resistor values. Have not analyzed/simulated differences though. Power stages (after fx loop) are completely different of course.

The extreme red channel is another interesting topic. I understand some swap to lower gain triode (ECC82) in first stage of overdrive circuit. I wonder if lowering the gain in second stage would be worth trying instead, as ECC832 tubes are more available than suggested ECC823. Perhaps a better idea if cold bias is also moved to first OD stage?


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## gdvsbp

grappo-soda said:


> Comparing to other available schematics for DSL amps (ie DSL20) the preamp is very much the same, other than a few decouple caps and some tweaks to resistor values. Have not analyzed/simulated differences though. Power stages (after fx loop) are completely different of course.
> 
> The extreme red channel is another interesting topic. I understand some swap to lower gain triode (ECC82) in first stage of overdrive circuit. I wonder if lowering the gain in second stage would be worth trying instead, as ECC832 tubes are more available than suggested ECC823. Perhaps a better idea if cold bias is also moved to first OD stage?



I was going to ask something about this today, and here I think you’ve about confirmed it for me. And now just to be _really _sure, here’s the question: I like the clean channel as-is, but would like to seriously reduce gain in the red channel. Would an ECC823 in V1 and an ECC832 in V2 reduce gain in 50% of the red channel’s gain stages while leaving the green’s gain as-is? I think that lines up with what I read elsewhere in this thread but would like to confirm before trying to source both tubes.

Thanks!


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## fitz

gdvsbp said:


> I was going to ask something about this today, and here I think you’ve about confirmed it for me. And now just to be _really _sure, here’s the question: I like the clean channel as-is, but would like to seriously reduce gain in the red channel. Would an ECC823 in V1 and an ECC832 in V2 reduce gain in 50% of the red channel’s gain stages while leaving the green’s gain as-is? I think that lines up with what I read elsewhere in this thread but would like to confirm before trying to source both tubes.
> 
> Thanks!


I can say that the JJ ECC823 in V1 works at reducing the gain on red and leaving the green as is.
There's still plenty of gain when cranked, it's just more controllable in between 1 & 10
I've never heard of putting an 832 in V2 - not saying it won't do something, I've just never tried it.


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## gdvsbp

fitz288 said:


> I can say that the JJ ECC823 in V1 works at reducing the gain on red and leaving the green as is.
> There's still plenty of gain when cranked, it's just more controllable in between 1 & 10
> I've never heard of putting an 832 in V2 - not saying it won't do something, I've just never tried it.


Excellent; that confirms the theory then, based on the signal path stated on page 4. I’m not looking for a lot of gain at all. (Why a DSL then? 3-band EQ, effects loop, master volume, and 0.1 watt power scaling doesn’t really come in any other packages.)

I’ve got a few 12AU7s sitting around, so I’ll swap those into V1 and V2 to see if it’s doing what I want to the red channel. If so, I’ll source the JJ ECC823/32 combo.


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## grappo-soda

The schematics were posted earlier in this thread (much obliged!) and from this it is clear the green/clean channel use 2nd triode of first tube and 1st triode of second tube. The OD circuit is then put in between these two stages. That means if you want to mod the red channel but keep green channel as is, you will need to use these odd mixed triode tubes such ECC823 in V1 or ECC832 in V2. 

Simplistic calculation would predict you get 11.5/26=44% (let’s say abt half) relative gain in first stage of OD circuit by using a ECC823 in V1. Also putting a ECC832 in V2 would reduce total gain even further (by factor 6.7/10=67%), but I think in practice it’s a question of either-or if you want some OD gain remaining on red channel. 
Also, as 2nd OD stage is a cold clipper i think most of that character would go away if you swap that triode?


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## grappo-soda

gdvsbp said:


> I’ve got a few 12AU7s sitting around, so I’ll swap those into V1 and V2 to see if it’s doing what I want to the red channel. If so, I’ll source the JJ ECC823/32 combo.


That wont work, unfortunately, as the red channel effectively uses all stages in both tubes. Putting eg ECC82 in V1 will affect both first two gain stages in red channel, not just one.


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## gdvsbp

grappo-soda said:


> That wont work, unfortunately, as the red channel effectively uses all stages in both tubes. Putting eg ECC82 in V1 will affect both first two gain stages in red channel, not just one.


Oh duh, that makes sense. Thanks for pointing that out.


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## Mavrim

Beartone said:


> What if the DSL1 fits the old Lead12 cab? And 12” speakers can fit in Lead 12. Not suggesting anyone should mod anything but Lead 12 does look a lot like DSL1.



I had purchased a broken tattoo JVM1 head. After repairing it, I sold the gigantic small box cabinet and trimmed the chassis to fit into a lead 12 cabinet. Worked out great! I unfortunately sold it because I wasn’t using it much. But the JVM1 is a great amp.


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## Mavrim

I just came across this thread that I started out regarding the extra speaker tap. I ended up putting the amp in the closet and moved on to a DSL20H that I absolutely love!

So cool that we finally have a schematic! I had called marshall about a problem on the JVM1 and they emailed a schematic for it. I posted that a while back! 

One thing I did on my DSL20H to match the older 1x12 cabinet was too make the shiny tolex look more like the elephant tolex on UK Marshall’s. I removed all plastic corners that are screwed on. I scuffed the tolex lightly with scotchbrite and then used armour all to add shine. I used gold marshall rivets to replace the screws. Now head is very close to matching the order tolex. I hate that fake shiny tolex they are using!


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## grappo-soda

Did anyone measure HT1-5 voltages?


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## Harbard

.


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## Rocketman

Happy Thanksgiving to everyone!!!


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## Rem223

This is a great thread. I really like my little DSL only wish the red channel had less compression and was more open sounding. Seems no mods have been posted to address this but possibly by using a ECC823 in V1 it might help. 

Also, does anyone have the full original Marshall schematic for this yet that they could post?

thanks!


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## fitz

Rem223 said:


> using a ECC823 in V1 it might help


 to the forum.
Give the 823 a try, it does make a difference.


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## WiderGates

So here it is:


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## gregr

Now we need the DFX board.


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## Max Gahne

The schematic @WiderGates posted has matched up to the DSL1 I bought in Nov 2020 although in recently doing some tinkering I noticed R91 on mine is 100K. Just pointing out that it looks like there's been that change since that schematic and there might be more.


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## Rem223

WiderGates said:


> So here it is:


Thanks!

I’ll check it out against my amp and see what we got!


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## Rem223

My 823 arrives this coming week. Looking forward to trying it out. 

I’d also like to find the schematic for the JCM1 or even SC20 (none in this forum that I could find posted) so I can compare the preamp and tone stack designs. Thinking if the 823 doesn’t quite do it for me that I might be able to change a few values here and there to get a little closer to the JCM’s open/mid focus tone, but keep the aspects of the DSL vibe that I really like. I like experimenting.


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## Wormscoffer

Mavrim said:


> If doing this mod fresh, I would have used a mini toggle switch.


@Mavrim It seems obvious but I just wanted to check. I don't want to add another socket or switch to my amp, which only arrived today, but if I pull the orange wire spade off the PCB and plug in the white one does that make my socket 8Ω ? I will only be using it with an 8Ω Greenback for the foreseeable future.


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## drklwo39

Wormscoffer said:


> @Mavrim It seems obvious but I just wanted to check. I don't want to add another socket or switch to my amp, which only arrived today, but if I pull the orange wire spade off the PCB and plug in the white one does that make my socket 8Ω ? I will only be using it with an 8Ω Greenback for the foreseeable future.


From what I understood in reading the rest of the posts, I do believe they debunked the 8 ohm tap as not being true, but from what I saw, it seems that since it’s so low wattage, that it wouldn’t really Hurt anything thought I could be wrong


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## manilaboy1vic

Ceerce said:


> Amp is "vietnam" version, pcb says y17w48.
> 
> 
> 
> 
> *Btw. If you are on ultragain / RED channel and have bass,middle at 12o'clock, then turn treble pot to full off, how does your amp change sound??? Use moderate gain and volume. *
> 
> That vietnamese DSL1 in my garage has weird behavior with treble off, modded or not... it first cut treble as it should but at zero, it regains treble, and change sound to something else, more mids, really different sounding DSL1 with treble off.


I did this to my new unmodified dsl1cr and the green channel is totally usable now..


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## Rocketman

manilaboy1vic said:


> I did this to my new unmodified dsl1cr and the green channel is totally usable now..


Interesting.


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## scozz

My Dsl1hr is anything but bright, I run it with the bass on 1 or 2 using the green channel, and on 0 in the red channel. Still not bright enough. 

I’m running through a 1-12 Greenback 25 cab. 

Running the bass off or really low helps reduce the compression, as well as the low end. 

I’ve also put a 5751 in v1 to help tame the gain and compression in the red channel. I’m liking the results. 

I’m thinking about trying a ecc823 in v1 at some point.


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## CalleGita

Hello,


I just installed ECC823 in V1 and an ECC832 in V2 on my Marshall DSL1CR , because I wanted Ultra Gain channel to be usable for my purposes ( Classic Rock, Blues, 70´s hard Rock).

I got just few minutes time to test it, but quick results were:


1. Clean channel is just about the same as previously

2. Ultra Gain is great now, more like Crunch / Dirt channel

- When Gain is on 1 it´s almost clean sound.

- When Gain is on 10 there is nice Iron Maiden / Black Sabbath 70´s distortion available.

- In between those are a lot of sounds to use.


Guitar will of course affect to the sound, so mine is PRS Mark Tremonti with Tonerider Birmingham Humbuckers.

The tubes cost about 50€ together and are available at least from uraltone.com (Finland), propably cheaper on other web-stores, but that one was 15 minutes away from home  

Installation was easy:
Just remove the back panel and use some cloth while carefully pull the oled one of an new in.

+++++ Remember to unplug the powerchord +++++

Let´s Rock ✌


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## MagB

Ceerce said:


> Amp is "vietnam" version, pcb says y17w48.
> 
> In that amp, i moved cold clipper stage from 3rd to 2nd stage, more traditional place in my opinion. Changed C5 to smaller value,it did help RED channel, and changed C9 to smaller value, for less high end. Added switch for cathode resistor(2nd stage), 1.8k / 10k / 33k. 1.8k is bypassed also with cap if needed. with 1.8k cathode resistor it sounded like different amp. 33k for more compress, SLO style CC.
> 
> First stage: switch for warm / middle(+bigger cap) / cold-ish bias , and plate resistor from 100k --> 220k.
> 
> it will take pedals much better, and cleans with more low end. i did add socket for C4, .022 originally, i will test more subs for it, and will test sound with modern hi-gain pedals, like clones of revv g2,g3,g4 etc.
> 
> 
> 
> I did add socket for C32. I tried and will try more subs for C32, IMO: better cleans with smaller cap, but pedals did sound harsh , so i did leave it empty for now. it had 0.68uF cap for 1st stage, i did add 2.2uF with 0.68uF, and cleans did get more lows.
> 
> I did also try cathode bypass 10uF cap for 4th stage, it had none originally... greens channel did get more dirt at higher gains, but it affected also to red channel, i believe that PI and FX loop didn't stand increased gain, those are solidstates. Maybe interstage dividers could be tweaked.... changing bias of 4th stage did not do much.
> 
> I did tweak this amp just for fun and curiosity, it is still "underconstruction". I have to wait my brother to visit and evaluate different mods...after all, it's his amp
> 
> Goal was to improve tolerance to pedals, and less "icy" ultragain sound.
> 
> 
> *Btw. If you are on ultragain / RED channel and have bass,middle at 12o'clock, then turn treble pot to full off, how does your amp change sound??? Use moderate gain and volume. *
> 
> That vietnamese DSL1 in my garage has weird behavior with treble off, modded or not... it first cut treble as it should but at zero, it regains treble, and change sound to something else, more mids, really different sounding DSL1 with treble off.


My DSL1CR does the same weird thing on green channel: by rolling off the treble it gets louder, more gainy and tightens up. On red channel the treble knob works as used to. Is it a circuit default or a fault?


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## CalleGita

CalleGita said:


> Guitar will of course affect to the sound, so mine is PRS Mark Tremonti with Tonerider Birmingham Humbuckers.
> 
> 
> +++++ Remember to unplug the powerchord +++++
> 
> Let´s Rock ✌


Well, it was a Dark Black Friday and i found myself walking out from the music store with Fender Playe stratocaster (SSS) ....

When I plugged it into Marshall, I noticed two things
- Red channel wasn´t gainy at all
- Humbuckers are much louder than sigle-coils, even splitted.

Today I had some extra time and restored original tubes to DLS 1 - I was pretty good as is.

After I tested different configutations i decided to left ELECTRO HARMONIX 12DW7 / ECC832 on V2.

- Green felt a little bit better (more singing sound -imho))
- Red channel was still gainy, but more controllable (IMHO)


MagB said:


> My DSL1CR does the same weird thing on green channel: by rolling off the treble it gets louder, more gainy and tightens up. On red channel the treble knob works as used to. Is it a circuit default or a fault?



I also tested this - and it´s weird - it seems that treble knob will make it louder when turned down, ow ever the other positin doesn´t affect the sound so much.

I actually left the treble off and adjusted the treble from guitar - now I think the sound is quite cool  

=> but it would be nice to know if it´s a bug or a feature


----------

