# Paolojm: New Amp Design And Build Thread



## PaoloJM

Guys,

I hope you dn't mind me posting this here.
It's gonna be a thread detailing the design and build of a new amplifier that I'm currently working on.
I'm posting it here because I know some of you guys are competant DIYers and many of the features of this amp are heavily "influenced" by my favourite Marshall amps.
It'll be for my own use only so don't worry, I'm not trying to flog anything.
During the thread I'll be happy to discuss any of the elements of the design and build with anyone interested, and even if you're not interested I'll simply talk at you!! 

I have a full time job and a two year old so updates may be only on a weekly basis but I often pop in for a chat so feel free to post any questions/ suggestions.

The philosophy of the design is to build as flexible an amp as possible but have absolutely zero compromise in the terms of build quality. 
This would be taking some of the switching possibilities of the likes of the DSL but implementing them without comprising the performance in any way.
I want an amp for both the studio and live performance.
It will be a head format.

On this post I'm gonna detail out the various design and feature elements of the amp. 

*Power Supply*
I'm basing my power supply on the Hammond 372JX.
This was selected for it's power capabilities (it's a 50 Watt design) and it's multiple LV taps.

The 5Vac will be rectified, doubled and filtered to supply my switching relays.

I'll be using a full wave bridge rectifier built with IN4007 diodes. These will be by passed with 10nF, 1,000V capacitors to smooth out switching transients.

The centre tap for the heater voltage will be referenced to a positive voltage derived from the B+. This is to further reduce the possibility of mains hum entering the signal chain.

There will be two switchable features within the power supply.
Vintage/Modern modes: 
In modern mode there will be a 200uF main filter capacitor. Using a SS rectifier along with a high capacitance will yield a stiff power supply which will work well to keep a defined low end for hard rock and metal tones.
The vintage mode will reduce the main filter cap value to 100uF and add a series power resistor between the rectifier and cap. This will emulate the valve rectifier and lower filtering of more vinatge amps.

Fluid/Choked modes:
This will allow switching between a resistive or inductive choke.
This choke I've selected is a Hammond 10H from the 15x series. 
With it in the circuit (choked mode) the low end will be even tighter and responsive.
In fluid mode this inductive choke is replaced with a power resistor, giving a slighly more compressed and rounded tone suitable for leads.

Both of these features will be presets, ie they will not be footswitchable.

*Power amp*
The power amp will use the Hammond 1650N output transformer.
It will be 60 Watts.
It will wired to take both EL34 and 6L6 type output valves. There will be a switch in the bias circuit to switch bias voltage range accordingly.
It will have a triode/pentode switch.

There will be a master resonance and presence control with switchable feedback options. Higher feedback resistor values for a more vintage feel and lower values for a tighter, more modern feel. 
This will also be a preset. Basically everything deal with power will be a preset.

There will be a master rhythm and mater lead control. This will be footswitchable and will allow for a lead volume boost.

*Preamp*
There will be two channel, clean and overdrive.
Each channel will have completely independant gain, bass, mid, treb and volume controls. Each gain control will have an assosiated bright switch and a voicing switch. the voicing switch will convert the tone stack from a more "brittish" to "american" sounding stack. Think Fender clean to Marshall overdrive perhaps? 

The first stage in the clean channel will be shared by both channels, 12AX7. 
Following that it will have two entirely independant stages. 
The two indipendant stage will be designed around a 12AU7. This tubes has nicer tone with more sperkly for cleans, to my ears anyway.

The overdrive channel will have two modes; overdrive and metal.
The overdrive mode will be voiced like a Plexi. The metal mode will add two additional gain stage and will be voiced like a hot-rodded JCM800 or a 5150.

The channel switching will also be footswitchable but the overdrive channel mode will be a preset.

There will be a valve driven FX Loop with options for parallel, series, bypass as well as loop send and return levels.

In total there will be five preamp valves.

That pretty much sums it up for now.

Parts are on order and I'm gradually transferring circuit design and layout from scraps of paper to proper formats in ExpressPCD and Panel Designer.

Look forward to sharing this and getting your input.


----------



## Wilder Amplification

PaoloJM said:


> Guys,
> 
> I hope you dn't mind me posting this here.
> It's gonna be a thread detailing the design and build of a new amplifier that I'm currently working on.
> I'm posting it here because I know some of you guys are competant DIYers and many of the features of this amp are heavily "influenced" by my favourite Marshall amps.
> It'll be for my own use only so don't worry, I'm not trying to flog anything.
> During the thread I'll be happy to discuss any of the elements of the design and build with anyone interested, and even if you're not interested I'll simply talk at you!!
> 
> I have a full time job and a two year old so updates may be only on a weekly basis but I often pop in for a chat so feel free to post any questions/ suggestions.
> 
> The philosophy of the design is to build as flexible an amp as possible but have absolutely zero compromise in the terms of build quality.
> This would be taking some of the switching possibilities of the likes of the DSL but implementing them without comprising the performance in any way.
> I want an amp for both the studio and live performance.
> It will be a head format.
> 
> On this post I'm gonna detail out the various design and feature elements of the amp.
> 
> *Power Supply*
> I'm basing my power supply on the Hammond 372JX.
> This was selected for it's power capabilities (it's a 50 Watt design) and it's multiple LV taps.
> 
> The 5Vac will be rectified, doubled and filtered to supply my switching relays.
> 
> I'll be using a full wave bridge rectifier built with IN4007 diodes. These will be by passed with 10nF, 1,000V capacitors to smooth out switching transients.
> 
> The centre tap for the heater voltage will be referenced to a positive voltage derived from the B+. This is to further reduce the possibility of mains hum entering the signal chain.
> 
> There will be two switchable features within the power supply.
> Vintage/Modern modes:
> In modern mode there will be a 200uF main filter capacitor. Using a SS rectifier along with a high capacitance will yield a stiff power supply which will work well to keep a defined low end for hard rock and metal tones.
> The vintage mode will reduce the main filter cap value to 100uF and add a series power resistor between the rectifier and cap. This will emulate the valve rectifier and lower filtering of more vinatge amps.
> 
> Fluid/Choked modes:
> This will allow switching between a resistive or inductive choke.
> This choke I've selected is a Hammond 10H from the 15x series.
> With it in the circuit (choked mode) the low end will be even tighter and responsive.
> In fluid mode this inductive choke is replaced with a power resistor, giving a slighly more compressed and rounded tone suitable for leads.
> 
> Both of these features will be presets, ie they will not be footswitchable.
> 
> *Power amp*
> The power amp will use the Hammond 1650N output transformer.
> It will be 60 Watts.
> It will wired to take both EL34 and 6L6 type output valves. There will be a switch in the bias circuit to switch bias voltage range accordingly.
> It will have a triode/pentode switch.
> 
> There will be a master resonance and presence control with switchable feedback options. Higher feedback resistor values for a more vintage feel and lower values for a tighter, more modern feel.
> This will also be a preset. Basically everything deal with power will be a preset.
> 
> There will be a master rhythm and mater lead control. This will be footswitchable and will allow for a lead volume boost.
> 
> *Preamp*
> There will be two channel, clean and overdrive.
> Each channel will have completely independant gain, bass, mid, treb and volume controls. Each gain control will have an assosiated bright switch and a voicing switch. the voicing switch will convert the tone stack from a more "brittish" to "american" sounding stack. Think Fender clean to Marshall overdrive perhaps?
> 
> The first stage in the clean channel will be shared by both channels, 12AX7.
> Following that it will have two entirely independant stages.
> The two indipendant stage will be designed around a 12AU7. This tubes has nicer tone with more sperkly for cleans, to my ears anyway.
> 
> The overdrive channel will have two modes; overdrive and metal.
> The overdrive mode will be voiced like a Plexi. The metal mode will add two additional gain stage and will be voiced like a hot-rodded JCM800 or a 5150.
> 
> The channel switching will also be footswitchable but the overdrive channel mode will be a preset.
> 
> There will be a valve driven FX Loop with options for parallel, series, bypass as well as loop send and return levels.
> 
> In total there will be five preamp valves.
> 
> That pretty much sums it up for now.
> 
> Parts are on order and I'm gradually transferring circuit design and layout from scraps of paper to proper formats in ExpressPCD and Panel Designer.
> 
> Look forward to sharing this and getting your input.



You know they make modelers that do that shit right?  *sarcasm*


----------



## MajorNut1967

We eagerly await your Skills & ingenuity. I can't wait to see and hear this one. I think its great you are using the Hammond X-fers, I've been very happy with them myself; much more refined then the other production trans.

Cheers Bro, make us proud!


----------



## MajorNut1967

Wilder Amplification said:


> You know they make modelers that do that shit right?  *sarcasm*



Hey Paolo don't worry about King Wanker, I mean King Wilder. He's not had his evening feed yet.


----------



## PaoloJM

Thanks for the input so far lads!!! 
The stuff is on it's way and should have some update over the weekend.

Major, you got on well with your Hammonds so? I've only used their chokes so far but read good reviews.


----------



## MajorNut1967

PaoloJM said:


> Thanks for the input so far lads!!!
> The stuff is on it's way and should have some update over the weekend.
> 
> Major, you got on well with your Hammonds so? I've only used their chokes so far but read good reviews.



Yes Paolo, I had excellent results with Hammond transformers. On the baby major I used the 1650N for the OT, it’s only rated at 60watts but you can push 100 thru it all day. And it had a 4300ohm IMP which was exactly what as recommended by GEC for the plate voltage I used. And I used the 290HX for power with a cap voltage doubler, it’s very stable.

You can take this for what its worth, but you know how everyone is Bonkers about MM and they are only one of two companies that make Marshall Major transformer replacements. For me they are over priced junk! The MM’s are a copy of an original Dagnall # 2008 Trans which were junk in the first place. But here’s what I have done on the last 5 OT replacements on a Major, I used the Hammond 1650WA with great success at 1/3 the MM cost. Plus my customer in Japan who is a Blackmore fanatic and I have modded his Major in a similar fashion to Blackmore’s early 70’s mods: cascaded V1 and the tone stack mods; he’s ecstatic with the amp using the Hammond OT.The IMP isn't perfect (1900ohms
) it should be 2150ohms, but I have had no blow up's and I just increased the UL tap resistors to 1k.


----------



## PaoloJM

MajorNut1967 said:


> Yes Paolo, I had excellent results with Hammond transformers. On the baby major I used the 1650N for the OT, it’s only rated at 60watts but you can push 100 thru it all day. And it had a 4300ohm IMP which was exactly what as recommended by GEC for the plate voltage I used. And I used the 290HX for power with a cap voltage doubler, it’s very stable.
> 
> You can take this for what its worth, but you know how everyone is Bonkers about MM and they are only one of two companies that make Marshall Major transformer replacements. For me they are over priced junk! The MM’s are a copy of an original Dagnall # 2008 Trans which were junk in the first place. But here’s what I have done on the last 5 OT replacements on a Major, I used the Hammond 1650WA with great success at 1/3 the MM cost. Plus my customer in Japan who is a Blackmore fanatic and I have modded his Major in a similar fashion to Blackmore’s early 70’s mods: cascaded V1 and the tone stack mods; he’s ecstatic with the amp using the Hammond OT.The IMP isn't perfect (1900ohms
> ) it should be 2150ohms, but I have had no blow up's and I just increased the UL tap resistors to 1k.



Cheers Major,
It was actually based on your reply a while ago regarding the major you built, as well as a few other articles, that I decided to go the Hammond route. Kevin O'Connor is also a big advocate of them.
Luckily so far I haven't had to replace too many transformers and so I simply haven't had the opportunity to test Hammonds out yet. The few transformers I have replaced I've had custom wound by Majestic Xformers in the UK and they were excellent, others I've gotten from Danbury but they're mostly lower powered.


----------



## MartyStrat54

I've used Hammonds on many tube HiFi amps that I've repaired. I love them.

My question is how do you get a lot of gain out of a 12AU7? If you split the 12AX7 between channels, that will give both channels an initial gain of around 100. Then you go into a 12AU7's with a gain factor of 17. How is that going to give you metal sounds?


----------



## PaoloJM

MartyStrat54 said:


> I've used Hammonds on many tube HiFi amps that I've repaired. I love them.
> 
> My question is how do you get a lot of gain out of a 12AU7? If you split the 12AX7 between channels, that will give both channels an initial gain of around 100. Then you go into a 12AU7's with a gain factor of 17. How is that going to give you metal sounds?



Thanks for the feedback on the transformers.

Maybe my post wasn't clear on the preamp.
The path for the clean channel will 1/2 12AX7 (shared by both channels) then onto a full 12AU7 dedicated to the clean channel only.
The dirty channel will use the same 1/2 12AX7 first stage as the clean channel. This channel has this stage cascaded into another 1/2 12AX7. For the metal tones there will another 2 1/2 12AX7 stage, voiced for metal, that can be switched in. The metal mode will have a total of 4 12AX7 gain stages cascaded into each other.
There will be three complete valves for the preamp tone shaping (six stages), one for the FX Loop and one for the PI giving a total of five preamp valves.
It'll be much clearer when I get the schematic done up properly.


----------



## MartyStrat54

Now your talking. That's a lot of 12AX7's. Is your design taken a little from the 6100?


----------



## Buggs.Crosby

<----is hiding under cover learning.....wishing i had enough knowledge to build stuff like this....i thank you Paolo...Jon ...and Major for posting your builds and passing on knowledge to those of us that dont have the full grasp on the technical aspects of your fine builds and repair info...most of my time spent here is reading new and old posts to gain some more insight on tube amps....gonna order some books this month to help learn some more basics then maybe buy a kit to help get me started...would have never thought to go here if it was not for you guys making me drool with your builds...so once again i say thank you guys for your posts....Cheers!


----------



## MajorNut1967

Buggs.Crosby said:


> <----is hiding under cover learning.....wishing i had enough knowledge to build stuff like this....i thank you Paolo...Jon ...and Major for posting your builds and passing on knowledge to those of us that dont have the full grasp on the technical aspects of your fine builds and repair info...most of my time spent here is reading new and old posts to gain some more insight on tube amps....gonna order some books this month to help learn some more basics then maybe buy a kit to help get me started...would have never thought to go here if it was not for you guys making me drool with your builds...so once again i say thank you guys for your posts....Cheers!



Paolo excuse the high jack! But Buggs you are welcome and hope I can help you, if you have any questions within my small range of knowledge? I cant speak for the other two guys, but I think they would surely be of help too. Those two are fetching Brilliant, much more so then I am.


----------



## PaoloJM

MajorNut1967 said:


> Paolo excuse the high jack! But Buggs you are welcome and hope I can help you, if you have any questions within my small range of knowledge? I cant speak for the other two guys, but I think they would surely be of help too. Those two are fetching Brilliant, much more so then I am.



No problem at all Major.

I'll second Major, ask away and I'll also try to answer from my limited knowledge.
I'm sure Jon will chime in with plenty of smart comments too!!


----------



## Wilder Amplification

PaoloJM said:


> No problem at all Major.
> 
> I'll second Major, ask away and I'll also try to answer from my limited knowledge.
> I'm sure Jon will chime in with plenty of smart comments too!!



'Tis my specialty...ESPECIALLY on new amp build threads.


----------



## PaoloJM

Got a knock on the door earlier and guess who it was?


I'll give you a clue, he drives a van....




Ah, f*ck it the first delivery just arrived!! 



 

 






Often times we seem to slag of the DSL/TSL series, particularly the transformers.
Here's why.



 

 

That's a TSL602 chassis which is in for some work. It is also 60 watts. 
I turned the OT on it's side and held it against the Marshall OT to show just how much difference there is. 
There's just no comparison, bigger really is better as far as xFormers goes.
I'm really impressed with the Hammond quality. They're big, heavy and just shout f*ck you!!
Can't wait to hear them. Thanks to Major for the recommendation.



Thought you might also be interest in seeing my work space.



 

 



That's my 2203 on the bench. It's getting a cap job and some minor mods. I'm putting progress pics of that in the JMP 50 thread if you're interested.


----------



## MartyStrat54

Everyone should have a room like this in their house. I just love the smell of solder in the morning.


----------



## MajorNut1967

MartyStrat54 said:


> Everyone should have a room like this in their house. I just love the smell of solder in the morning.



I am absolutely with you on this one Marty!


----------



## Procter2812

Hey Paolo..

you seem to have the metal ends off the DSL trannys.. How come?

Is this to help heat escape?

keep it up.. im sure it will be awesome!


----------



## MajorNut1967

Hey did you monkeys see Paolo's bloody Bean Can AMP! LOL
It's fetchin great!

[ame=http://www.youtube.com/watch?v=w_qZHzuaxBU&feature=channel]YouTube - Amp in a bean can[/ame]


----------



## Wilder Amplification

Procter2812 said:


> you seem to have the metal ends off the DSL trannys.. How come?
> 
> Is this to help heat escape?



According to "Valve Amps Demystified" by Frankie, this is correct, but the amp has to be grounded in order for this trick to work.   *sarcasm*


----------



## MajorNut1967

Wilder Amplification said:


> According to "Valve Amps Demystified" by Frankie, this is correct, but the amp has to be grounded in order for this trick to work.   *sarcasm*



 Frankie couldn't demystify a hemorrhoid, let alone a Tube Amplifier!


----------



## Wilder Amplification

MajorNut1967 said:


> Frankie couldn't demystify a hemorrhoid, let alone a Tube Amplifier!



Hence my *sarcasm* tag


----------



## PaoloJM

Hi guys,

Yup, I'd say it should be mandatory for every man to have a room or shed in the house with a lockable door and just his stuff in there.
This could be power tools and workbench, big screen to watch the footy and a beer fridge or in my case music gear and electronics stuff.
I'd go nuts otherwise, especially with two "ladies" about the house!! 

This amp cam in with no end bells on. The head DSL/TSLs have end bells of course but this is the first combo model I've seen. I would have thought there should have been end bells but there is no evidence that I can see of them being removed.  
The amp is FUBAR anyways and the guy doesn't want to pay for a new board so he left me it with me for parts.
Anyone know whether they're supposed to be there on combos as a matter of interest? I've seen many lower powered amps with endbellless transformers but not anything this size before.
In general, IMO, if the transformer is over heating then there is something wrong and removing the end bells is not the solution.

Did I miss something with Frankie and this "Valve Amps Demystified" thread?
Don't think I saw that one but sounds interesting!!

Hey Major, that's for the promotion of the bean can amp!! It still gets regular use as a signal tester although the o'scope is starting to make it redunant...


----------



## MajorNut1967

PaoloJM said:


> Hi guys,
> 
> Did I miss something with Frankie and this "Valve Amps Demystified" thread?
> Don't think I saw that one but sounds interesting!!
> 
> Hey Major, that's for the promotion of the bean can amp!! It still gets regular use as a signal tester although the o'scope is starting to make it redunant...



No you didn't miss a thread Mate! Just some opinions on "true ability!"

I want to build a fetchin Bean Can amp now, with a 12AX7 in it. LOL


----------



## MartyStrat54

I built a bass bean can amp. I used a 32 ounce can as my chassis and I was able to build a single ended amp inside using one 6L6. I also made a reverb tank out of an old tuna can and it fit right in. It has Reverb, Presence, Bass, Mid, Treble and a Pre and Master volume. Sounds great with guitar. Just like some of them old Marshall Bass amps. Anyhow, I'm going to build a guitar amp in one of these 32 ounce cans and I am going to get with Jon on building an opto-coupled tremelo unit as well as reverb, so that would be two, tuna cans. 

Hey only the best. All ceramic sockets and the best electronic parts from Chicago. All point-to-point wiring. I'm going to get started on it as soon as I finish eating all of these beans. 

I guess that brings a new meaning about, "I'm really gassing for this amp."


----------



## Procter2812

MajorNut1967 said:


> Frankie couldn't demystify a hemorrhoid, let alone a Tube Amplifier!



 that made me laugh.


----------



## MajorNut1967

Procter2812 said:


> that made me laugh.



Cheers Bro, have a smile on us!


----------



## PaoloJM

*Update: Schematic (partially) complete*

Hope everyone had a great xmas and my best wishes to all for the new year.

Been real busy and festive cheers lately so haven't had much to put into my amp design/build.
Did manage to get some time though, and here is the first draft schematics of the power supply, power amp and FX loop, drawn out using Express PCB.
Just click on the pics to get the bigger versions.
The preamp is also finished but is still in napkin format!! 


Power Supply




The bias supply is intended to have adequate range to cover both EL34 and 6L6 type valves, that's the purpose of the switch. I'll be testing out 6L6GC, KT66, KT77, EL34, 6V6 etc. once the amp is finished.
The valve emul switch will introduce some sag, reminicent of using a valve rectifier. The sag works well for blues and classic rock but I'll bypass it for hard rock and metal. This worked well in my last amp build.
The choke can be switch between a 10H inductor and a 470 ohm power resistor.
The filtering can be changed from 100u to 200u for the higher gain hard rock and metal stuff.
Each preamp stage is decoupled to ensure no motorboating or weird distortions.
The heater centre tap is referenced to the screen voltage @ around 60Vdc. DC referencing the centre tap and tightly twisting the heater wires eliminates any heater hum. This worked really well in my last build.
The third tap is providing around 6Vdc for the relays. The 1st relay will switch channels, the second kicks in the solo boost and the third switches the appropriate LED to indicate the channel. Channel LEDs are not shown here.


FX Loop and Power Amp




The FX Loop is lifted pretty much directly from The Ultimate Tone by Kevin O'Connor. It's based on a 12AT7. I selected it as, in theory anyway, it should be completely transparent. 
I originally wanted to have a properly designed SS loop, to get it truely transparent, but didn't want to mess with yet another LV supply.
The power amp design is pretty much stock stuff seen in every amp since the early Fenders. The feedback loop has a control to make the power amp feel tighter or looser. This worked really well in my last build.



Values shown may change as the design is refined. 
You should not build blindly from these schematics and there may well be errors that may lead to injury.

I'm not claiming to have invented anything here but I did spend a lot of time trying and testing things, refining things, figuring how and why certain things work (and don't), working out how to combine things and establishing what I felt would work best for me as a guitarist, so I am kinda proud of the work put in. 


As usual I'm happy to discuss any part of the design, and welcome any comments or suggestions you may have.


----------



## MartyStrat54

Looking good. I'll be staying in touch. I mean this is going to be a really killer amp. After all, it's a two channel with a lot of tweaking capabilities.


----------



## Joey Voltage

Alright I guess I will be the asshole here. A couple of observations:

100uf worth of filtering in the vintage mode is still a ton of filtering, way more (and stiffer) than you would ever even need for a build like this in modern mode. I would lower it more if this is your true goal.

swapping a 470r resistor for the choke probably wont give you the amount of sag or roundness you are looking for, especially if you plan on running the pa fairly clean.


----------



## Buggs.Crosby

I so want the Slash in a Bean can Amp...that was Fucking awesome...how much
for one and can i supply the can?
dont know all the techy stuff but that sure is alot of flexibility...why dont other companies offer options like this? is it just a cost thing...a reliability issue?
and one other question if i may...is a ss loop that much better/transparent than a valve one? if so is it just an efficiency issue from the lack heat dissipation that makes it so?


----------



## PaoloJM

Joey,
100uF is the value that the early 70s JMP50s used and that's the feel I'm looking for. The valve rectifier emulator will loosen things up even more if needed.
200uF is pretty much necessary for a modern high gainer that stays tight and doesn't get too noisy, think SLO100, Dual Rectifier etc.
I see the choke switch more for getting a more fluid feel, when using a lot of gain, for soloing. I like a really tight tone for metal riffing but find it a little stiff for lead playing, and that's where this would come in.

Buggs,
Thanks for checkin' out my vids. I'm not selling anything, but maybe some day, you never know...
A well designed SS loop will be more transparent than a valve based one. 
The objective of any loop is to drive the FX and not alter the tone made by the amp. 
Valves, by their nature, colour the tone and it's very hard to design that out.
SS devices can be made extremely linear, which is normally why we don't like the tone but we're not create tone with the loop driver, we want it to be an exact replica of the signal it's fed. 
I opted for the K O'C loop design for maximum transparency while not needing to worry about a regulated LV supply, which a SS loop would require.
Hope that answers your questions.



Well here's my preamp, at last.
The Overdrive mode switch has the second pole NC contacts inverted because I couldn't figure out how to invert the symbol!! It will work when wired up.

The clean channel is modelled after an early Fender or Mesa Lone Star, though I've placed the tone stack after the second stage which I prefer.
The tone stack switch will allow for a more mid range tone, like those American/Brittish tone switches you see on some amps.

The Overdrive channel has two "modes", overdrive and lead.
The overdrive should be pretty close to a JMP50 type tone and the lead should be more like a SLO100, 5150 etc.
Again the tone stack has a voicing switch.

Each channel has a brite switch.





Next step is to export a componant BOM, see what I have in my bag of tricks and order the rest. 
I also have the layout and the drilling templates for the chassis complete. 
Will be starting drilling and punching it during the week.


----------



## jcmjmp

Sweet. What kinda tone are you after on this one? It sounds like you're going for a high gain amp.


----------



## PaoloJM

jcmjmp said:


> Sweet. What kinda tone are you after on this one? It sounds like you're going for a high gain amp.



Well the theory is that the cleans should be Fenderish, the OD should be "Plexyish" and the lead should be 5150/SLOish.
The channel control and solo boost will be footswitchable.

The amp is intended for gigging and the studio. 
The power supply has a lot of flexibility for the "feel" of the amp, but they are presets. 
Idea being they'd be set in the most appropriate position for a gig. 
In the studio you could have a tight/stiff sounding metal machine for riffing and then flick a switch for a more fluid feel to cut solos without going to a different amp.
It should act a bit like a vintage/modern switch.
Different power valve types should bring out a different charactor as well as playing with the negative feedback switch.
I'm bascially hoping to cover all bases in one amp.


----------



## MajorNut1967

Looks very nice Paolo, lots of thought put into it. Would like to hear samples when done.


----------



## Joey Voltage

PaoloJM said:


> Joey,
> 100uF is the value that the early 70s JMP50s used and that's the feel I'm looking for. The valve rectifier emulator will loosen things up even more if needed.
> 200uF is pretty much necessary for a modern high gainer that stays tight and doesn't get too noisy, think SLO100, Dual Rectifier etc.
> I see the choke switch more for getting a more fluid feel, when using a lot of gain, for soloing. I like a really tight tone for metal riffing but find it a little stiff for lead playing, and that's where this would come in.



If you did the math you would see that 100uf worth of filtration for the main filter cap of a 50W build *IS* very stiff, and leaves very low ripple. Over filtering can actually lead to problems, as does under filtering. 220uf is completely unnecessary in this application, and There are tons of super tight punchy high gainers on the market that use less than this. 

Subbing a 470r resistor for a choke is going to buy you nothing but somewhat higher noise/poorer regulation, and voltage drop. If you are running the PA fairly clean like you typically would in a high gain amp where you are relying on a lot of preamp distortion, you most likely wont take advantage of the "sag" you would get from using a resistive element instead of an inductive one, because the PA will be drawing fairly constant currents from the HT If it's not being pushed, you may be better off voicing the "solo" mode to be darker and squishier, rather than relying on the 470r resistor to do it.


----------



## PaoloJM

Joey Voltage said:


> If you did the math you would see that 100uf worth of filtration for the main filter cap of a 50W build *IS* very stiff, and leaves very low ripple. Over filtering can actually lead to problems, as does under filtering. 220uf is completely unnecessary in this application, and There are tons of super tight punchy high gainers on the market that use less than this.
> 
> Subbing a 470r resistor for a choke is going to buy you nothing but somewhat higher noise/poorer regulation, and voltage drop. If you are running the PA fairly clean like you typically would in a high gain amp where you are relying on a lot of preamp distortion, you most likely wont take advantage of the "sag" you would get from using a resistive element instead of an inductive one, because the PA will be drawing fairly constant currents from the HT If it's not being pushed, you may be better off voicing the "solo" mode to be darker and squishier, rather than relying on the 470r resistor to do it.



I did do the math and looked extensively at amps I like the tone of. That's how I arrived at this values. If I find that I don't like the tone I can always change them around.

The choke is only filtering the screens and preamp, not the power valve plates, and so actually will have the opposite affect to what you describe .ie it will have more affect in a highly overdriven preamp feeding a clean power amp, and that is the purpose here.
Many, many people (myself included) notice a massive difference in high gain amps (5150 et al) when using an inductive choke. I've found that I like inductive chokes for punchy rhythm playing but miss the more fluid feel of the resistor for lead playing.


----------



## Brett Blackmore

Hi PaoloJM,

I wish I could understand all of this but I have only half a clue... I wish you well with the project. I am interested to hear the 3 channels...

ps- I agree with the solid-state vs. valve soution for the fx-loop - with SS there is a higher headroom and less hum from the heater etc...

Cheers Brett


----------



## jcmjmp

MajorNut1967 said:


> Looks very nice Paolo, lots of thought put into it. Would like to hear samples when done.



+1

This does sound like it would be part Soldano part plexi. The Soldano Lucky 13 sounds close to what this would be; at least 2/3 of it.


----------



## PaoloJM

jcmjmp said:


> +1
> 
> This does sound like it would be part Soldano part plexi. The Soldano Lucky 13 sounds close to what this would be; at least 2/3 of it.




Cheers jcmjmp and Major.
The circuit as drawn in theory should sound in the Fender clean, Plexi overdrive and SLO lead type tone region.
I'm not going to be looking for exact replicas of these tones (that'd be a bit mad!!), but I'm going for that kind of territory and then tweak it to my own taste. Hopefully I'll end up with something kinda unique....as unique as the first JTMs were from the Bassman anyways. 

Joey, I do appreciate your input, please don't feel like I'm ignoring it. If the amp does end up sounding too "stiff" then dropping the filtering a bit will certainly be the first thing I try.


----------



## Joey Voltage

PaoloJM said:


> I did do the math and looked extensively at amps I like the tone of. That's how I arrived at this values. If I find that I don't like the tone I can always change them around.
> 
> The choke is only filtering the screens and preamp, not the power valve plates, and so actually will have the opposite affect to what you describe .ie it will have more affect in a highly overdriven preamp feeding a clean power amp, and that is the purpose here.
> Many, many people (myself included) notice a massive difference in high gain amps (5150 et al) when using an inductive choke. I've found that I like inductive chokes for punchy rhythm playing but miss the more fluid feel of the resistor for lead playing.





The preamp draws next to nothing even under severly over driven situations, and draws very constant currents to boot, they will not fluctuate the HT much, if at all. I Promise you!, and will not cause significant sag to the PS, thats part of the reason you don't see a single choke in a stand alone preamp, amongst other reasons. In all the high gain amps I have replaced that resistor in, i have worked on plenty of Peavey's, the biggest thing I have noticed is better noise performance, and less voltage drop. 

Look at it, how much are you nominally drawing from your preamp? if you are assuming a measily 1Ma per triode, and even less for that cold stage, a bit more for the higher current 12AT7, doesn't amount to much does it?

now if you are assuming a 50W amp, and you have a typical supply of 450V, and even assuming the worse case 100% dissipation, which of course it wont be, you are drawing about 111ma at the plates (remember worse case scenario), and about 17MA for the screens, add that to the small 10ma or so for the whole preamp we'll call it about 140ma. Now say you want to allow only 5% ripple (which is pretty damned smooth,), a 56uf-68uf cap will do it, and would be considered stiff, 100uf allows even less ripple, and is by all means more Stiff.

Take into consideration also, you stated that you researched amps and copied certain aspects from them, most of which were 100W-120W amps.


----------



## PaoloJM

Just a quick update for ya on this project.

As you probably guessed work pretty much stopped since January, haven't been posting much here either.

Since xmas my work (the day job) has gotten mentally busy (not complaining!! ), I've moved to a new house which was unfurnished so I've assembled massive amounts of flat packed furniture, and ontop of that I've been to Paris for two weeks.

Anyways things are getting back to normal now.

The new workshop is almost up and running properly and I started working on this amp in it last week.
The amp power supply and power amp is now up and running. 
All features working as planned. 
It scoped out fine with a test signal into the phase inverter and there's no smoke or fire yet!! 

Already the originally neat and tidy wiring is becoming messy as I'm tweaking values. Wilder, Joey or some of the other guys will testify to how butchered looking a prototype amp can start to look after a few tweaking sessions. 

I've been taking pics but haven't had a chance to load them as I literally only have enough desk space cleared for the amp chassis.

I'm gonna finish furnishing and setting up the room this week (apparently women think that kitchens, living rooms, bedrooms etc. are more important than silly hobby rooms and should be done first....) and start into the preamp then.


----------



## strathaze

Buggs.Crosby said:


> <----is hiding under cover learning.....wishing i had enough knowledge to build stuff like this....i thank you Paolo...Jon ...and Major for posting your builds and passing on knowledge to those of us that dont have the full grasp on the technical aspects of your fine builds and repair info...most of my time spent here is reading new and old posts to gain some more insight on tube amps....gonna order some books this month to help learn some more basics then maybe buy a kit to help get me started...would have never thought to go here if it was not for you guys making me drool with your builds...so once again i say thank you guys for your posts....Cheers!



Same boat as you Buggs. Its frustrating kinda understanding but not quite enough to tackle a project like Paolo is doing. Do what I'm doing, I bought a epiphone valve jnr and I've added a boost switch and a master volume to it, its been great fun, a tone contol will be next. But thanks Paolo and Jon for sharing the knowledge with guys like us


----------



## MartyStrat54

Well if you realize that it is going to need some tweaking, hey it's a prototype. I do go along with Joey about making the power supply to stiff. If you derived your numbers from working amps, then it should fly, but I do have one question.

Say one channel works good with the power supply, but it's too stiff on the other two. How do you find a happy medium for three different channels that in theory want their own particular power supply to sound their best?

That's got to be one of the main tricks to building a multi-channel amp. Getting the power supply built right.


----------



## Wilder Amplification

MartyStrat54 said:


> Well if you realize that it is going to need some tweaking, hey it's a prototype. I do go along with Joey about making the power supply to stiff. If you derived your numbers from working amps, then it should fly, but I do have one question.
> 
> Say one channel works good with the power supply, but it's too stiff on the other two. How do you find a happy medium for three different channels that in theory want their own particular power supply to sound their best?
> 
> That's got to be one of the main tricks to building a multi-channel amp. Getting the power supply built right.



Stiffness of the power supply has more to do with how the power amp reacts with it. The preamp doesn't draw hardly any current (like MAYBE in the 10-15mA range max) so the supply barely notices that it's there. It's the power amp that taxes the current supply and is what makes the difference between a stiff and a saggy power supply.

That being said...you can drop the available voltage to the preamp which will reduce the headroom of the preamp itself.


----------



## Joey Voltage

Wilder Amplification said:


> Stiffness of the power supply has more to do with how the power amp reacts with it. The preamp doesn't draw hardly any current (like MAYBE in the 10-15mA range max) so the supply barely notices that it's there. It's the power amp that taxes the current supply and is what makes the difference between a stiff and a saggy power supply.
> 
> That being said...you can drop the available voltage to the preamp which will reduce the headroom of the preamp itself.



If I were even to go further and make a sweeping statement, I would say the screens have probably the most influence. the screens on El34's for example are current hogs, and enevitably are responsible for taxing the plate supply!


----------



## Joey Voltage

MartyStrat54 said:


> Well if you realize that it is going to need some tweaking, hey it's a prototype. I do go along with Joey about making the power supply to stiff. If you derived your numbers from working amps, then it should fly, but I do have one question.
> 
> Say one channel works good with the power supply, but it's too stiff on the other two. How do you find a happy medium for three different channels that in theory want their own particular power supply to sound their best?
> 
> That's got to be one of the main tricks to building a multi-channel amp. Getting the power supply built right.



Well I guess my point originally was that there's only so far you should go, (or have to really), in order to get the desired result. and sometimes what appears to be a cut and dry issue, really isn't. (there can be ill effects in overfiltration too)

also when I first saw the scheme, I thought some things looked a little redundant, and probably could have been simplified just for the sake of sanity.


----------



## PaoloJM

Yep, things have changed a fair bit since the original schematics I posted.
Some simplification and consolidaiton of functions.
The more I thought about it the more :eek2::eek2::eek2: I thought Joey was right :eek2::eek2::eek2::eek2:. 

The power supply now has one simple vintage/modern switch.
Vintage mode has 64uF main filter with a 150 ohm sag resistor, modern has 164uF without the sag resistor. This is instead of two seperate functions previously.
When everything is up and running fully I will also try it with 32uF and 132uF for the main filtering. The 64uF cap is a dual 32uF can.

I've kept the choke/resistor switch, 'cos I like what it does in a 5150.

The FX Loop is now a simple series loop, designed to be as transparent as possible. 
The more I read and tried out other guys parallel loops the more it seemed like I was adding the series/parallel switch function just 'cos I could. 
The FX that I use all work far better in a series loop.

The preamp is now intended to be a straight up two channel, clean and dirty.
I've decided to keep the tone stack switching and Mesa style solo boost function though. The solo boost is a great function on a Dual Rec IMO.


Martystrat, to answer your question; in modern mode I want a crystal clear clean sound and a tight overdrive. In vintage mode I want a loose, slightly overdriven clean and a loose, creamy overdrive. 
This power amp design should serve both well. 
I don't really see a time where I'd want vintage clean and modern overdrive, or vise versa, though it could be done with relays.
My playing styles and the two bands I'm in fall into two rough catagories; blues/classic rock and hard rock/metal.

Remember my original concept; 
This amp is going to be the ultimate amp for my personal use, so everything is designed around my requirements. 
I'm not really trying to imagine what functions other people might want as I'm not planning on selling any.
Sounds egotistical but f*ck it, I studied and practised for long enough, now I'm reaping the rewards.


This is why I love this forum, intelligent input from knowledgeable guys. Please keep the comments and suggestions coming.


----------



## Joey Voltage

PaoloJM said:


> The FX Loop is now a simple series loop, designed to be as transparent as possible.
> The more I read and tried out other guys parallel loops the more it seemed like I was adding the series/parallel switch function just 'cos I could.
> The FX that I use all work far better in a series loop.



IIRC, you are using O'Connors loop? O'Connors loop is way over engineered for what it is really doing, and can be simplified to allow the same if not better performance, with the same functionality and not so many parts or board space required.


----------



## PaoloJM

Joey Voltage said:


> IIRC, you are using O'Connors loop? O'Connors loop is way over engineered for what it is really doing, and can be simplified to allow the same if not better performance, with the same functionality and not so many parts or board space required.



Yeah I was.
Ditched the idea now though. I didn't really need or want a parallel loop and the KO'C one seemed to be more of a lesson on virtual earth mixers than a practical loop to me.
Gone for a simple series loop similar to the one below from the valvewizards page, but with a few changes to fit it within my circuit.


----------



## jcmjmp

PaoloJM said:


> Yeah I was.
> Ditched the idea now though. I didn't really need or want a parallel loop and the KO'C one seemed to be more of a lesson on virtual earth mixers than a practical loop to me.
> Gone for a simple series loop similar to the one below from the valvewizards page, but with a few changes to fit it within my circuit.



That looks a lot like the Silver Jubilee loop. Why not try the SDM loop (you can get it from MetroAmp)


----------



## Joey Voltage

PaoloJM said:


> Yeah I was.
> Ditched the idea now though. I didn't really need or want a parallel loop and the KO'C one seemed to be more of a lesson on virtual earth mixers than a practical loop to me.
> Gone for a simple series loop similar to the one below from the valvewizards page, but with a few changes to fit it within my circuit.



The only thing about merlins loop is that you are limited on how much return gain you have, but the 12au7 driver is probably the best choice you can use. I would reccommend a 12DW7 for a best of both worlds scenario, although if you are using rack stuff you probably don't need more return gain. Also Ve stages for the return are also about as good as you can get for that application because of their head room, large bandwidth, and ability to hide aging, but O'connors is way over engineered, and has unecessary parts, that cause more phase shifts with in the loop. I have an easier one that I may shoot you that sounds really good, and is just as full featured as oconnors, uses less parts, and has a true mix function.

I'm a big fan of tube loops mostly because of their ability to swing large signals, and because they overdrive more gracefully if you do happen to overload them.... something SS has yet to accomplish.



jcmjmp said:


> Why not try the SDM loop (you can get it from MetroAmp)



because that costs money, and I think the point is to learn how to stand on your own feet, when you are designing


----------



## PaoloJM

Joey Voltage said:


> The only thing about merlins loop is that you are limited on how much return gain you have, but the 12au7 driver is probably the best choice you can use. I would reccommend a 12DW7 for a best of both worlds scenario, although if you are using rack stuff you probably don't need more return gain. Also Ve stages for the return are also about as good as you can get for that application because of their head room, large bandwidth, and ability to hide aging, but O'connors is way over engineered, and has unecessary parts, that cause more phase shifts with in the loop. I have an easier one that I may shoot you that sounds really good, and is just as full featured as oconnors, uses less parts, and has a true mix function.
> 
> I'm a big fan of tube loops mostly because of their ability to swing large signals, and because they overdrive more gracefully if you do happen to overload them.... something SS has yet to accomplish.
> 
> 
> 
> because that costs money, and I think the point is to learn how to stand on your own feet, when you are designing




Cheers Joey, if you have a design that you don't mind sharing with me then that'd be cool. Thanks very much for your input.

Just finished off testing the power amp and supply.
Pushing out a clean 66 Watts with no cross over distortion, which isn't bad for a pair of 6L6GCs. That's using a 1k signal into the PI and measuring across an 8 ohm, purely resistive load.
Clipping/slight cross-over only begins at 8 on the master volume (it reaches 66 Watts @ 7) so it's meets the clean power amp criteria. EL34s will begin to break up much earlier which is part of the overall plan.
It's been running for over 10 hours now on the bench with no issues and has passed the chop stick poking test!!

I promise I will post pics soon, including the scope traces so far.


----------



## Wilder Amplification

PaoloJM said:


> Cheers Joey, if you have a design that you don't mind sharing with me then that'd be cool. Thanks very much for your input.
> 
> Just finished off testing the power amp and supply.
> Pushing out a clean 66 Watts with no cross over distortion, which isn't bad for a pair of 6L6GCs. That's using a 1k signal into the PI and measuring across an 8 ohm, purely resistive load.
> Clipping/slight cross-over only begins at 8 on the master volume (it reaches 66 Watts @ 7) so it's meets the clean power amp criteria. EL34s will begin to break up much earlier which is part of the overall plan.
> It's been running for over 10 hours now on the bench with no issues and has passed the chop stick poking test!!
> 
> I promise I will post pics soon, including the scope traces so far.



66 watts out of a pair of 6L6s...that sounds like a very healthy power supply and a good match on the plate load.

If you posted it earlier I didn't see it...what's the Zp-p load on the OT you're using? And what B+ are you seeing?

I just got the plate transformer in for the dual rail prototype. 450VAC @ 500mA on the HT winding with a 6 amp heater winding, which gives me PLENTY of reserve current on the heater winding for channel switching circuit, although I may instead elect to have a 24VAC CT winding on the screen tranny. Next month hopefully I'll be getting the screen tranny and the output transformer for it. Workin' on gettin' the big/more expensive parts in first (always easier to do things that way ). It'll be going in a JCM800 size chassis.


----------



## PaoloJM

Wilder Amplification said:


> 66 watts out of a pair of 6L6s...that sounds like a very healthy power supply and a good match on the plate load.
> 
> If you posted it earlier I didn't see it...what's the Zp-p load on the OT you're using? And what B+ are you seeing?
> 
> I just got the plate transformer in for the dual rail prototype. 450VAC @ 500mA on the HT winding with a 6 amp heater winding, which gives me PLENTY of reserve current on the heater winding for channel switching circuit, although I may instead elect to have a 24VAC CT winding on the screen tranny. Next month hopefully I'll be getting the screen tranny and the output transformer for it. Workin' on gettin' the big/more expensive parts in first (always easier to do things that way ). It'll be going in a JCM800 size chassis.




Z p-p is 4,300 ohms B+ is 423Vdc and V scr is 420Vdc.
Obviously I only expect to see around 40 Watts clean with an EL34 as the plate load is not ideal.

Are you drilling your chassis yourself?
I must go back and read your build thread in more detail. It seems like our concepts aren't a million miles removed ie big, bold, clean power amp and most of the tone shaping happening in the preamp.
I'm looking forward to seeing some pics and hearing the clips.


----------



## Wilder Amplification

PaoloJM said:


> Z p-p is 4,300 ohms B+ is 423Vdc and V scr is 420Vdc.
> Obviously I only expect to see around 40 Watts clean with an EL34 as the plate load is not ideal.
> 
> Are you drilling your chassis yourself?
> I must go back and read your build thread in more detail. It seems like our concepts aren't a million miles removed ie big, bold, clean power amp and most of the tone shaping happening in the preamp.
> I'm looking forward to seeing some pics and hearing the clips.



According to my power calculations on your setup -

Zp-p / 4 = Zp-ct

4300 / 4 = 1075 Ohm Zp-ct

423^2 / 1075 = 166 Watts Peak

166Wpk / 2 = 83Wavg

83Wavg x 0.7(70%) = 58 Watts

Not too far off from what you're seeing...you're actually seeing about 80% of the primary Wavg according to my math.

Now with EL34s, if this amp had a 480 volt plate voltage, EL34s would be an excellent candidate for a 4.3K load since isn't too far off from the 4.5K load that the load line gave me for EL34s at that voltage. According to my calculations above, with the increased plate voltage you should see roughly about 75 watts provided a stiff supply voltage without exceeding the average plate dissipation. BUT...

The exception would be that you'd wanna dual rail your screens down to about 400 volts due to the screen voltage limit of EL34s (425-450 max).

Our goals aren't that far removed at all. But since you're using 6L6s due to their plate voltage handling limit they're not very well suited to dual rail operation like KT88/6550s are.


----------



## PaoloJM

Wilder Amplification said:


> According to my power calculations on your setup -
> 
> Zp-p / 4 = Zp-ct
> 
> 4300 / 4 = 1075 Ohm Zp-ct
> 
> 423^2 / 1075 = 166 Watts Peak
> 
> 166Wpk / 2 = 83Wavg
> 
> 83Wavg x 0.7(70%) = 58 Watts
> 
> Not too far off from what you're seeing...you're actually seeing about 80% of the primary Wavg according to my math.
> 
> Now with EL34s, if this amp had a 480 volt plate voltage, EL34s would be an excellent candidate for a 4.3K load since isn't too far off from the 4.5K load that the load line gave me for EL34s at that voltage. According to my calculations above, with the increased plate voltage you should see roughly about 75 watts provided a stiff supply voltage without exceeding the average plate dissipation. BUT...
> 
> The exception would be that you'd wanna dual rail your screens down to about 400 volts due to the screen voltage limit of EL34s (425-450 max).
> 
> Our goals aren't that far removed at all. But since you're using 6L6s due to their plate voltage handling limit they're not very well suited to dual rail operation like KT88/6550s are.



Just rechecked the scope as I thought the reading was a shade higher than expected with that B+ myself.
The centre line was slightly off centre giving me a more generous V rms than I deserved!! The probes are on a factor of 10 to read properly on the screen, meaning a slight shift from centre can mean a pretty high error as I've just seen!! 
It looked like I had around 32 V peak but when centrered properly it actually only reads around 30 V peak, giving around 55/6 Watts using Vrms.
The joys of a good old CRT scope!!


I'm not there with the dual rail idea, but it's like an interesting idea. I read a bit about it in my RCA Receiving Tube Manuals. Can't wait to see how yours turns out.
I'm deliberately keeping B+ lower so that I can also use 6V6s in there too for a different flavour.


----------



## Wilder Amplification

PaoloJM said:


> Just rechecked the scope as I thought the reading was a shade higher than expected with that B+ myself.
> The centre line was slightly off centre giving me a more generous V rms than I deserved!! The probes are on a factor of 10 to read properly on the screen, meaning a slight shift from centre can mean a pretty high error as I've just seen!!
> It looked like I had around 32 V peak but when centrered properly it actually only reads around 30 V peak, giving around 55/6 Watts using Vrms.
> The joys of a good old CRT scope!!
> 
> 
> I'm not there with the dual rail idea, but it's like an interesting idea. I read a bit about it in my RCA Receiving Tube Manuals. Can't wait to see how yours turns out.
> I'm deliberately keeping B+ lower so that I can also use 6V6s in there too for a different flavour.



Well how about that? That puts you right in at about 4-6% of my calcs. Funny how the math works ain't it? 

Yeah it'll be a few months before I have the working prototype. But it's definitely in process of. Will be interesting to see what it's like to play through it.

BTW since you're in Ireland, ever listen to the band Fastway?


----------



## PaoloJM

Wilder Amplification said:


> Well how about that? That puts you right in at about 4-6% of my calcs. Funny how the math works ain't it?
> 
> Yeah it'll be a few months before I have the working prototype. But it's definitely in process of. Will be interesting to see what it's like to play through it.
> 
> BTW since you're in Ireland, ever listen to the band Fastway?



Yup, your maths are spot on.
I had calculated something around that aswell based on the PT stated secondary Vac.
Of course real life and theory are never quite the same, but it's pretty darn close!! 

Months for sound clips of your amp? I don't have kind of time, speed things up!! 
I'll bet it'll be like driving a monster truck. Many other amps floundering about but the power and precision of the big boy just crushes them all. Starting to wonder if 56 Watts is gonna be enough!!


----------



## Wilder Amplification

PaoloJM said:


> Yup, your maths are spot on.
> I had calculated something around that aswell based on the PT stated secondary Vac.
> Of course real life and theory are never quite the same, but it's pretty darn close!!
> 
> Months for sound clips of your amp? I don't have kind of time, speed things up!!
> I'll bet it'll be like driving a monster truck. Many other amps floundering about but the power and precision of the big boy just crushes them all. Starting to wonder if 56 Watts is gonna be enough!!



Well if my model proves a success...you just may start seeing some 200 and 300 watt valve guitar amps around. Since the solid state guys got smart and started up'ing the ante in regards to stepping their output power up high enough to compete with the valve amps, we gotta do something to keep the "valve watts are louder than solid state watts" tradition alive. 

I'm curious as to which speakers to pair this sucker up with. I'm thinkin' either the Celestion K100s or...quite possibly...the EV M-12L. Now THAT would "bring the br00tlz bra". 

What's the source current rated at on that PT? I set mine at 450VAC @ 500mA based on a 600V loaded B+ -

Zp-p = 5K

600 x 2 = 1200Vpk-pk

1200^2 / 5K = 288Wpk

288Wpk / 2 = 144Wavg

144Wavg / 70% =100Wavg

Zp-ct = 1250 ohms

600V / 1250 Ohms = 480mA Ipk

Which also works out as -

288Wpk / 600Vpk = 480mA Ipk

Or -

600 x 0.707 = 424.2Vrms

480mA x 0.707 = 340ma Irms

424.2Vrms x 340mA = 144Wavg

If my math is right, depending on the % regulation of the PT I'm thinking this thing ain't gonna even come close to sag...with a total 100uF filtering at the reservoir cap this thing may prove to be too tight...who knows?


----------



## PaoloJM

Here's the progress pics eventually...


These are old pics now but show the chassis after I drilled it, primed and laquored it.


 

 




Everyone loves the heaters shot, hope my twists are up to scratch!! 


 




It got to a point on the power amp that so many things were "tweaked" on the power board after it was up and running that I decided to take the power board back out and tidy everything up. 
It's important for me to ensure that the amp will be reliable and easily maintainable, and so a backwards step was required.
The amp will benefit from it in the long run, I hope.
The bias circuit may still require tweaking but that's ok, you can see a piggy backed resistor in there at the moment on the power boards pics below.
The 7806 regulator will be fitted tomorrow and the board will be re-installed.
I'm hoping to have that, as well as the FX Loop, finished by tomorrow evening so I can plug a guitar in for the first time.


Power transformer installed


 


All X formers installed





This is the EZ Board for tube town. Not very professional looking but perfect for a proto-type build like this.





Power amp end after the power board has been removed.





Here's the power board as it is today.


----------



## Wilder Amplification

That's a pretty damn beefy output tranny for a 50-60 watter. I'd have some pics up of the dual rail build if Heyboer would hurry up with my screen and output trannies.


----------



## PaoloJM

Wilder Amplification said:


> That's a pretty damn beefy output tranny for a 50-60 watter. I'd have some pics up of the dual rail build if Heyboer would hurry up with my screen and output trannies.




Yup, cool isn't it?  I was real impressed with the hammond iron.

Looking forward to seeing the dual rail, not sure if I've ever seen a real one.


----------



## MajorNut1967

PaoloJM said:


> Here's the progress pics eventually...
> 
> 
> These are old pics now but show the chassis after I drilled it, primed and laquored it.
> 
> 
> Everyone loves the heaters shot, hope my twists are up to scratch!!
> [
> 
> It got to a point on the power amp that so many things were "tweaked" on the power board after it was up and running that I decided to take the power board back out and tidy everything up.
> It's important for me to ensure that the amp will be reliable and easily maintainable, and so a backwards step was required.
> The amp will benefit from it in the long run, I hope.
> The bias circuit may still require tweaking but that's ok, you can see a piggy backed resistor in there at the moment on the power boards pics below.
> The 7806 regulator will be fitted tomorrow and the board will be re-installed.
> I'm hoping to have that, as well as the FX Loop, finished by tomorrow evening so I can plug a guitar in for the first time.
> 
> 
> Power transformer installed
> 
> All X formers installed
> 
> 
> This is the EZ Board for tube town. Not very professional looking but perfect for a proto-type build like this.
> 
> Power amp end after the power board has been removed.
> Here's the power board as it is today.
> ]



Bloody beautiful Paul! I like the welded corners good taste. Aluminum Chassis got to love it. Those EZ boards are great love the proto-type look. And Hammond Tranformers it will sound great. Excellent work on a true proto-type.


----------



## Wilder Amplification

PaoloJM said:


> Yup, cool isn't it?  I was real impressed with the hammond iron.
> 
> Looking forward to seeing the dual rail, not sure if I've ever seen a real one.



If you've seen an Ampeg SVT or an old Music Man amp, you've seen a dual rail amp.

I just drew up the graphical component layout of the plate/screen power supply board this morning -






The mains is jumper configurable for 120 or 240VAC operation.


----------



## PaoloJM

Wilder Amplification said:


> If you've seen an Ampeg SVT or an old Music Man amp, you've seen a dual rail amp.
> 
> I just drew up the graphical component layout of the plate/screen power supply board this morning -
> 
> 
> 
> 
> 
> 
> The mains is jumper configurable for 120 or 240VAC operation.



Efficient use of resistors for the main cap voltage balance, charge drainage and heater centre tap supply. Why use four when three would do!!

Are you doing anything to loosen up the screen supply? 
Seems like a a good xformer hooked directly to the full wave would have very little impedance and so be quite stiff.
If it's Wilder proprietry info then that's cool!!


----------



## Wilder Amplification

PaoloJM said:


> Efficient use of resistors for the main cap voltage balance, charge drainage and heater centre tap supply. Why use four when three would do!!
> 
> Are you doing anything to loosen up the screen supply?
> Seems like a a good xformer hooked directly to the full wave would have very little impedance and so be quite stiff.
> If it's Wilder proprietry info then that's cool!!



Remember? It's a "br00tlz" amp! It's supposed to be stiff! 

Actually...I'm gonna wait until I build it, then see what it gives me. If nothing else I just may incorporate the choke/sag resistor switch, using something like an 820R for a sag resistor (screens on KT88s at full output only draw about 15mA a piece and since they're on their own dedicated rail you'd have to use a higher value to get it to sag). For now though the choke is a Mercury MC10-H 10 Henry choke.

Yeah the "split bleeder" arrangement was something I came up with while I was trying to simplify the schematic. Using a 180K and a 39K with a 300 volt supply gives about a +53V elevated reference while also yielding a 219K total resistance, which is close enough to 220K.

Another thing this amp will feature is 4 speaker jacks. 2 x 8 ohm, 1 x 4 ohm, and the other will be switchable between the 4 and 16 ohm tap. This will give the ability to run singles of each impedance, doubles of 16 or 8 ohm, as well as being able to run a single 16 along with a single 8 ohm while still keeping the impedance matched.


----------



## Wilder Amplification

You know Paolo...I think you may have just given me a kick ass idea on my build...

I wonder how valve rectified screens would work/sound/feel on this bitch? Maybe switchable screen rectifiers?


----------



## Joey Voltage

Wilder Amplification said:


> You know Paolo...I think you may have just given me a kick ass idea on my build...
> 
> I wonder how valve rectified screens would work/sound/feel on this bitch? Maybe switchable screen rectifiers?



wouldn't bother, If you use valve rectification, I would use parallel valves and use it for the plate supply like Bruce did, especially if you use the plate supply for the preamp as well, will be beneficial concerning noise as well this way. If you are just trying to loosen the screen supply, a simple resistor will work fine, cost less, require no extra holes, and save you from worrying about extra filament supplies.

also one critique, I would move the elevated supply further downstream. the cleaner the better. drawing it from the first preamp stage node will be the most ideal, and may also help contribute a nicer load on the supply when you are taking measurements without valves in.


----------



## Joey Voltage

Wilder Amplification said:


> That's a pretty damn beefy output tranny for a 50-60 watter.



Should be.. It's a Hi-Fi tranny with a 30hz -30Khz response at a -1db deviation. It's not rated, or intended for a guitar amp, and if you play your cards right, you can use it for a 80-100W guitar amp, easily!


----------



## MajorNut1967

Joey Voltage said:


> Should be.. It's a Hi-Fi tranny with a 30hz -30Khz response at a -1db deviation. It's not rated, or intended for a guitar amp, and if you play your cards right, you can use it for a 80-100W guitar amp, easily!



You think any of the early or proto-type output transformers were specifically built for guitar amp or for that matter now day's even. Whether its Hi-Fi or not doesn't matter anyway. I think this first below par thing you've ever said, don't! And any of you who don't believe Hammond transformers aren't suited for guitar, better think again; Traynor and some others have always used the H trans. Just cause it dont say: Drake or Dagnall or MM on it!


----------



## MajorNut1967

PaoloJM said:


> Yup, cool isn't it?  I was real impressed with the hammond iron.
> 
> .



I'm glad you chose that H Iron Paolo, then you can truly judge for yourself!


----------



## MajorNut1967

So Paolo are you related to the Earl of Cork, the Boyles?


----------



## rads

MajorNut1967 said:


> I'm glad you chose that H Iron Paolo, then you can truly judge for yourself!



Hi Major, i saw your JCM800 thread was using Magnetic trannys.
How are they compared to Hammond?
My friend recommended me to use Hammond, but my budget only for those magnetics, since the shipping cost to home (+ custom fee) is killing me..
And their comparation demo was quite interesting, yet no hammond was tested.


----------



## PaoloJM

Joey Voltage said:


> Should be.. It's a Hi-Fi tranny with a 30hz -30Khz response at a -1db deviation. It's not rated, or intended for a guitar amp, and if you play your cards right, you can use it for a 80-100W guitar amp, easily!



Yup, the SLOs use HiFi OTs too I think. Joey can you verify, you the man on the SLOs?
The idea was that the OT should not effect the frequency reponce of the amp, I'm a control freak!!


----------



## Joey Voltage

MajorNut1967 said:


> You think any of the early or proto-type output transformers were specifically built for guitar amp or for that matter now day's even. Whether its Hi-Fi or not doesn't matter anyway. I think this first below par thing you've ever said, don't! And any of you who don't believe Hammond transformers aren't suited for guitar, better think again; Traynor and some others have always used the H trans. Just cause it dont say: Drake or Dagnall or MM on it!



re-read what I said wasn't dissin' the transformer dude, was commenting on why it is so large and, and presenting the idea to Paolo, or anybody else that since it wasn't rated or intended specifically for guitar amp use, it can be used for a much higher power build if he wanted.


----------



## Joey Voltage

PaoloJM said:


> Yup, the SLOs use HiFi OTs too I think. Joey can you verify, you the man on the SLOs?
> The idea was that the OT should not effect the frequency reponce of the amp, I'm a control freak!!



Yes Indeed the SLO's OT is a Hi-Def tranny. You can probably get something comparable by specing one with a 20Hz - 20Kh frequency response and a 2.2K reflected primary (100W), but the problem is that these specs really tell you very little about the OT, or how it sounds, and I don't think anybody to this day has even attempted to reverse the DeYoungs that are in there. The closest you can get Off the shelf is the Onetics one, and it's bloody expensive. That transformer is really the key to getting that amp to sound right, It's one of the reasons that circuit sounds sub-par, or just straight up bad in every other amp that copies it.

Part of the reason he also might have spec'd it that way is because the slo uses quite a bit of feed back in comparison to some others that are not particularly stable with less, although I may be giving him too much credit.


----------



## PaoloJM

Joey Voltage said:


> Yes Indeed the SLO's OT is a Hi-Def tranny. You can probably get something comparable by specing one with a 20Hz - 20Kh frequency response and a 2.2K reflected primary (100W), but the problem is that these specs really tell you very little about the OT, or how it sounds, and I don't think anybody to this day has even attempted to reverse the DeYoungs that are in there. The closest you can get Off the shelf is the Onetics one, and it's bloody expensive. That transformer is really the key to getting that amp to sound right, It's one of the reasons that circuit sounds sub-par, or just straight up bad in every other amp that copies it.
> 
> Part of the reason he also might have spec'd it that way is because the slo uses quite a bit of feed back in comparison to some others that are not particularly stable with less, although I may be giving him too much credit.



Yeah, I was figuring a difference of 20 vs 30 Hz in low end would make much difference in a guitar amp. My thinking was that my circuit (pretty much SLO) would sound somewhere between SLO and 5150 which wouldn't be a bad place to be IMO.
London Power also use these and I've heard good things so I'm hoping it works well.
Time will tell I guess.
This OT should all be man enough for impedance mis-matching too.


----------



## jcmjmp

Love it so far. I can't wait to hear some clips.


----------



## Joey Voltage

PaoloJM said:


> Yeah, I was figuring a difference of 20 vs 30 Hz in low end would make much difference in a guitar amp.



For the circuit in your scheme, most likely not.



PaoloJM said:


> My thinking was that my circuit (pretty much SLO) would sound somewhere between SLO and 5150 which wouldn't be a bad place to be IMO.



maybe Somewhat, but another part of the way that circuit sounds is in the supply voltages around 360VDC for the preamp, 380 for the PI, and later gainstages, and 470 or so for the PA. The back to back CF's, and the larger plate loads matter too. part of the 5150's magic lies in that extra gain stage even though it isn't contributing much, and that unity gain VE stage that drves the TS. I would say yours may be closer to an XTC/recto hybrid from what I remember.


----------



## MajorNut1967

Joey Voltage said:


> re-read what I said wasn't dissin' the transformer dude, was commenting on why it is so large and, and presenting the idea to Paolo, or anybody else that since it wasn't rated or intended specifically for guitar amp use, it can be used for a much higher power build if he wanted.



Joey I was giving you crap! sorry it was a joke. LOL


----------



## MajorNut1967

rads said:


> Hi Major, i saw your JCM800 thread was using Magnetic trannys.
> How are they compared to Hammond?
> My friend recommended me to use Hammond, but my budget only for those magnetics, since the shipping cost to home (+ custom fee) is killing me..
> And their comparation demo was quite interesting, yet no hammond was tested.



Rads howzit Mate! 

I don’t think it’s even about comparing. It’s more like this. “the Hammond transformer is made much more refined then the usual production transformers (Drake, Dagnall, RS and Partridge) and there is a mystique that these production transformers were of high quality. This wasn’t true they just worked and were cheap and sound good. So Since I wanted a stock type trans I gave Magnetics a shot and it happened to work out. And why didn’t I buy a MM trans, over priced whooya. 

Ok why no test of a Hammond trans in the comparison mostly be because they don’t advertise as “Guitar amp ultimate transformer” Like Mercury Fagnetics, Heyboer, Weber. They business is much more then just transformers and I believe this because the tranny’s are much more refined sounding some Marshall enthusiast may not like them either! But when I build my Baby Major clones I only use Hammond trannys. But for a stock 50 watt or 100 Watt EL34 amp Magnetics Components or Heyboer, but just my opinion! By the way Hammond is now making a line of drop-in replacements for most popular guitar amps so we’ll see how the public bites.


----------



## solarburn

MajorNut1967 said:


> Rads howzit Mate!
> 
> I don’t think it’s even about comparing. It’s more like this. “the Hammond transformer is made much more refined then the usual production transformers (Drake, Dagnall, RS and Partridge) and there is a mystique that these production transformers were of high quality. This wasn’t true they just worked and were cheap and sound good. So Since I wanted a stock type trans I gave Magnetics a shot and it happened to work out. And why didn’t I buy a MM trans, over priced whooya.
> 
> Ok why no test of a Hammond trans in the comparison mostly be because they don’t advertise as “Guitar amp ultimate transformer” Like Mercury Fagnetics, Heyboer, Weber. They business is much more then just transformers and I believe this because the tranny’s are much more refined sounding some Marshall enthusiast may not like them either! But when I build my Baby Major clones I only use Hammond trannys. But for a stock 50 watt or 100 Watt EL34 amp Magnetics Components or Heyboer, but just my opinion! By the way Hammond is now making a line of drop-in replacements for most popular guitar amps so we’ll see how the public bites.



I LoL'd


----------



## Joey Voltage

Marshall/Fender Ot's are really just a small part of what Magnetic Components really does too (they used to be called Marvel Magnetics, you can see why they probably changed it) . They are a pretty big OEM manufacturer like Hammond, and I think guitar amp tranny's are quite new to them. I wouldn't think twice about using one, have before, good priced, and they grabbed a bunch of good engineers from Schumacher before they lost the death struggle with Mercury Fagnetics. It's too bad they only offer a limited range, or will only do a 25 piece minimum order for custom designs.


----------



## Wilder Amplification

Joey Voltage said:


> Marshall/Fender Ot's are really just a small part of what Magnetic Components really does too (they used to be called Marvel Magnetics, you can see why they probably changed it) . They are a pretty big OEM manufacturer like Hammond, and I think guitar amp tranny's are quite new to them. I wouldn't think twice about using one, have before, good priced, and they grabbed a bunch of good engineers from Schumacher before they lost the death struggle with Mercury Fagnetics. It's too bad they only offer a limited range, or will only do a 25 piece minimum order for custom designs.



Actually...according to literature on the Magnetic Components site they've been making guitar amp trannys for a long time. Some OEMs used their stuff and rebranded them. They'd have an EIA code of "166" on them if they were made by Magnetic Components...and I seem to recall seeing that EIA code on a few old Fender transformers.


----------



## Joey Voltage

Wilder Amplification said:


> Actually...according to literature on the Magnetic Components site they've been making guitar amp trannys for a long time. Some OEMs used their stuff and rebranded them. They'd have an EIA code of "166" on them if they were made by Magnetic Components...and I seem to recall seeing that EIA code on a few old Fender transformers.



Very possible! I have no doubt their stuff has been used in guitar amps previously, as they have been the house brand company for antique, CE dist, Mojo, and a few others for many years. I also know a few boutique companies that use them. the "newly breaking out" in the guitar amp business was in regard to branding themselves. although I really wish they hadn't gone the paper bobbin snake oil route...... That was recent.


----------



## rads

great info guys...
Major, Jon and Joey...a bunch of thanks for you guys..


I'm ordering a set of JCM800 2204 transformer from Magnetics Comp.


----------



## Wilder Amplification

Joey Voltage said:


> also one critique, I would move the elevated supply further downstream. the cleaner the better. drawing it from the first preamp stage node will be the most ideal, and may also help contribute a nicer load on the supply when you are taking measurements without valves in.



The reference has 210uF of total filtering...how much cleaner do you want it? There's no current being drawn from it since it's just a floating point reference (except for what the 39K divider resistor is drawing, which isn't more than 1.5mA) so it's not like the HCT is gonna tax it at all.


----------



## PaoloJM

Wilder Amplification said:


> The reference has 210uF of total filtering...how much cleaner do you want it? There's no current being drawn from it since it's just a floating point reference (except for what the 39K divider resistor is drawing, which isn't more than 1.5mA) so it's not like the HCT is gonna tax it at all.




That's of course assuming that your heater CT is actually in the centre. 
Knowing you I'd guess you a pair of well matched 100 ohms in the instead though.


----------



## Wilder Amplification

PaoloJM said:


> That's of course assuming that your heater CT is actually in the centre.
> Knowing you I'd guess you a pair of well matched 100 ohms in the instead though.



Actually the voltages on my heater CT are pretty damn close. However, I may try both the CT itself and the 2 x 100R artificial CT and see if I notice a difference. Chances are there won't be though.


----------



## Joey Voltage

Wilder Amplification said:


> (except for what the 39K divider resistor is drawing, which isn't more than 1.5mA) so it's not like the HCT is gonna tax it at all.



It's not about taxing anything


----------



## MajorNut1967

solarburnDSL50 said:


> I LoL'd



I'm sorry that was a typo! Sorry Solar I would never say anything ill about those over-priced assholes.


----------



## Wilder Amplification

Joey Voltage said:


> It's not about taxing anything



The reason I mentioned about taxing is that the ability of a filter cap to provide enough filtering is governed by how much current the filter cap's storage capacity can source vs how much the load is pulling from it (supply and demand). Obviously, if there's not enough filtering to satisfy the load placed on the caps, you'll have some ripple. But with 210uF total filtering at that point in the circuit, 1.5mA ain't shit for a load on the caps so there shouldn't be any ripple worth mentioning at that point.


----------



## Joey Voltage

Wilder Amplification said:


> The reason I mentioned about taxing is that the ability of a filter cap to provide enough filtering is governed by how much current the filter cap's storage capacity can source vs how much the load is pulling from it (supply and demand). Obviously, if there's not enough filtering to satisfy the load placed on the caps, you'll have some ripple. But with 210uF total filtering at that point in the circuit, 1.5mA ain't shit for a load on the caps so there shouldn't be any ripple worth mentioning at that point.



Think about what I said originally and potential benefit it would have........ I'm not going to give it away that easily , It may be a greater one over economizing over a .13 cent part. Also I do see a potential flaw in your original supply design, I don't know if you have fixed it though........


----------



## PaoloJM

Quick progress report.

Was playing an SD1 through the Loop return tonight at low volumes, my 2.5 year old is in bed.
Sounds great at low volumes anyway!
I'm as far as the DC coupled cathode following in the OD channel.
Two more valves to wire, the switching circuitry, tone stack for the clean channel and I'm good to go. Weeks of tweaking will follow no doubt...

I'm off to bed, it's 2.27am and I started at 7pm yesterday!!


----------



## Joey Voltage

PaoloJM said:


> Quick progress report.
> 
> Was playing an SD1 through the Loop return tonight at low volumes, my 2.5 year old is in bed.
> Sounds great at low volumes anyway!
> I'm as far as the DC coupled cathode following in the OD channel.
> Two more valves to wire, the switching circuitry, tone stack for the clean channel and I'm good to go. Weeks of tweaking will follow no doubt...
> 
> I'm off to bed, it's 2.27am and I started at 7pm yesterday!!



Ooooh! one thing i looked at your pre scheme a little just now, I would watch some of it a little in the OD channel, you may run into some blocking, or woofyness. there are a couple of things that jump out. Here are some things to consider once you build it: the first coupling cap is rather large for the nearly fully bypassed cathode, and with that load, especially when the gain pot is up past 5 or 6. I would either lower the coupling cap to 470pf - .001uf, shelf the 470K source, or shelf the cathode. 

the other potential I see is the .022uf bypass between the second and 3rd stage. you are basically creating a short with that cap... that 470k source is basically not there for all audio frequencies. I would lower it if you want to achieve any useful shelving, or get rid of both the 470K series, and .022uf bypass, as it is essentially the same thing with out either.


----------



## PaoloJM

Joey Voltage said:


> Ooooh! one thing i looked at your pre scheme a little just now, I would watch some of it a little in the OD channel, you may run into some blocking, or woofyness. there are a couple of things that jump out. Here are some things to consider once you build it: the first coupling cap is rather large for the nearly fully bypassed cathode, and with that load, especially when the gain pot is up past 5 or 6. I would either lower the coupling cap to 470pf - .001uf, shelf the 470K source, or shelf the cathode.
> 
> the other potential I see is the .022uf bypass between the second and 3rd stage. you are basically creating a short with that cap... that 470k source is basically not there for all audio frequencies. I would lower it if you want to achieve any useful shelving, or get rid of both the 470K series, and .022uf bypass, as it is essentially the same thing with out either.



Hey man, thanks for the input. Just spotted the .022uF in the schema now. It should read .0022uF, I was copying and pasting componants to save time. I think I'm gonna make it partially switchable, maybe put a 82k in series and using a by-pass switch to bring it in partially or fully, like a upper mid boost switch.

That's why should not just blindly follow published schematics folks!! 


On the first coupling capacitor, I can't shelve the 470k as it would also drop top end from the clean channel and I definitely don't want that.
I want a full bandwidth gain stage on the input so shelving the cathode isn't an option.
I was hoping that a 500k with a brite cap as the dirty gain control (the plexi switching option is now gone for simplicity) should bring in the shelving I want. Of course dropping to a 250k pot with brite cap might just seal the deal, hopefully. I'll find out on tomorrow I reckon.


----------



## Wilder Amplification

PaoloJM said:


> Hey man, thanks for the input. Just spotted the .022uF in the schema now. It should read .0022uF, I was copying and pasting componants to save time. I think I'm gonna make it partially switchable, maybe put a 82k in series and using a by-pass switch to bring it in partially or fully, like a upper mid boost switch.
> 
> That's why should not just blindly follow published schematics folks!!
> 
> 
> On the first coupling capacitor, I can't shelve the 470k as it would also drop top end from the clean channel and I definitely don't want that.
> I want a full bandwidth gain stage on the input so shelving the cathode isn't an option.
> I was hoping that a 500k with a brite cap as the dirty gain control (the plexi switching option is now gone for simplicity) should bring in the shelving I want. Of course dropping to a 250k pot with brite cap might just seal the deal, hopefully. I'll find out on tomorrow I reckon.



For full bandwidth stages, have you ever tried diode biasing them?


----------



## Joey Voltage

PaoloJM said:


> On the first coupling capacitor, I can't shelve the 470k as it would also drop top end from the clean channel and I definitely don't want that.
> I want a full bandwidth gain stage on the input so shelving the cathode isn't an option.
> I was hoping that a 500k with a brite cap as the dirty gain control (the plexi switching option is now gone for simplicity) should bring in the shelving I want. Of course dropping to a 250k pot with brite cap might just seal the deal, hopefully. I'll find out on tomorrow I reckon.



Ah, I see. if the cap is small enough though, 470pf or so, the high frequency roll off when the clean is in would only be 7K - 8K, which isn' t too bad........


----------



## PaoloJM

Finished the dirty channel.
Sounds great at low volume anyway.
The treble control is doing some odd things and I'm not sure that the feedback loop is working right but they're probably just silly errors.

Clean channel and switching circuitry to go.

Will post clips and pics when I've time.


Wilder, at one point I was toying with the idea of using a LED to bias the stage and mount it through the chassis as a stand-by light.
Then I went down the voltage regulator route for my switching and LEDs, a great decision as it happens, and kinda forgot about it.
Maybe on another project.


----------



## PaoloJM

First clips at low volume with the digi cam.

[ame=http://www.youtube.com/watch?v=mSdXtThkHDc]YouTube - 50 Watt First Amp Demo[/ame]


----------



## solarburn

More more more!


----------



## PaoloJM

solarburnDSL50 said:


> More more more!



Cheers dude,

Some more tweaks done. I'm going for the 5150 type "brootz" tone here.
Still at real low volumes (you can hear the pick attack again) but you should get the idea.
You opinions and constructive criticisms are welcome, it'd be great to hear what you guys think tone wise.

[ame]http://www.youtube.com/watch?v=9RiNRg5Mq7E[/ame]


----------



## Wilder Amplification

I didn't know Flogging Molly sounded like that.  jk

Just got the rest of the iron in for mine today. Will be takin' and postin' pics soon.

I've got a 5H and a 10H choke here, and will probably end up getting a 3H from MM as well to figure out how much choke I want on the screens.

As soon as I have a blank chassis, some filter caps, valve sockets and a pair of KT88s I'll be mock wiring the power amp up and testing it out.


----------



## solarburn

PaoloJM said:


> Cheers dude,
> 
> Some more tweaks done. I'm going for the 5150 type "brootz" tone here.
> Still at real low volumes (you can hear the pick attack again) but you should get the idea.
> You opinions and constructive criticisms are welcome, it'd be great to hear what you guys think tone wise.
> 
> YouTube - 60 Watt Dirty Channel test



That was a good brootz tone. Thick and chunky bottom end with definition. Liked the bit of lead tone it has on single notes. Seemed to have good mid character(didn't sound scooped out). Do a little bit more lead while you are demonstrating the rhythms so I can here sustain and how/when it goes into musical feedback. Are you using a cab and what speakers if you are? Hows if feel in the room? I know its low volume here are you able to crank it at all to feel it too? With all that gain is it noisy feedback wise? How about background hiss?

Sounds real good man. I like it.


----------



## Joey Voltage

It's getting there, definitely has that SLO mid character


----------



## PaoloJM

Wilder Amplification said:


> I didn't know Flogging Molly sounded like that.  jk
> 
> Just got the rest of the iron in for mine today. Will be takin' and postin' pics soon.
> 
> I've got a 5H and a 10H choke here, and will probably end up getting a 3H from MM as well to figure out how much choke I want on the screens.
> 
> As soon as I have a blank chassis, some filter caps, valve sockets and a pair of KT88s I'll be mock wiring the power amp up and testing it out.



Cheers Wilder.
Now hurry up and get your amp done, pressure's on!! 



solarburnDSL50 said:


> That was a good brootz tone. Thick and chunky bottom end with definition. Liked the bit of lead tone it has on single notes. Seemed to have good mid character(didn't sound scooped out). Do a little bit more lead while you are demonstrating the rhythms so I can here sustain and how/when it goes into musical feedback. Are you using a cab and what speakers if you are? Hows if feel in the room? I know its low volume here are you able to crank it at all to feel it too? With all that gain is it noisy feedback wise? How about background hiss?
> 
> Sounds real good man. I like it.



Thanks man. The amp is driving my 2 X 12 which is loaded with a V30 and a G12H. My girlfriend and baby are heading out for the day on Thursday so I'll get some recording done at a decent volume then. Can't bring it to my rehearsal space to record because there's wires still hanging out of it and I've no head shell yet!
I'm real happy noise wise so far, I stopped playing dead a few times so people could hear relative noise levels and it's pretty low I think for such a high level of gain. It feeds-back with the gain on 10 but the clean channel is not yet wired and it's gain control acts as an additional load on the dirty channel, so I'm not going to worry about that yet. It's clean as a whistle all the way to about 8/8.5 and I think wiring the clean channel will solve the rest, it's an easy fix if not.



Joey Voltage said:


> It's getting there, definitely has that SLO mid character



Cheers Joey, I'm gonna leave tweaking now until I get some proper volume going. I suspect the amp is going come alive a lot more once the power valves start doing their thang. I'll assess it properly then.
By the way, I took your advise re using a 1uF on the first stage. It let's you role up the resosance and bass tone control a little for low end power rather than low end distortion. You were right, it just seemed a little wooly in the first clip with 10uF in there.
Depending on how the high volume testing goes I may actually try a .68 or.47uF there.



I think the FX Loop is working great but I've no proper loop FX to test. Even the crappy Boss ME-50 crappy out after 9 years the other day. The only FX I use are wah and a clean boost, must go out and get a delay or something...


----------



## Joey Voltage

PaoloJM said:


> Cheers Joey, I'm gonna leave tweaking now until I get some proper volume going. I suspect the amp is going come alive a lot more once the power valves start doing their thang. I'll assess it properly then.
> By the way, I took your advise re using a 1uF on the first stage. It let's you role up the resosance and bass tone control a little for low end power rather than low end distortion. You were right, it just seemed a little wooly in the first clip with 10uF in there.
> Depending on how the high volume testing goes I may actually try a .68 or.47uF there.



heh, I had a sneaking suspicion you were going to go that route




PaoloJM said:


> I think the FX Loop is working great but I've no proper loop FX to test. Even the crappy Boss ME-50 crappy out after 9 years the other day. The only FX I use are wah and a clean boost, must go out and get a delay or something...



Which one did you end up going with? probably the VW one as it is the easiest to install.


----------



## PaoloJM

Joey Voltage said:


> heh, I had a sneaking suspicion you were going to go that route
> 
> 
> 
> 
> Which one did you end up going with? probably the VW one as it is the easiest to install.



I ended up with a redesigned VW version. Using a 12AU7 was causing a larger voltage *DROP* in the preamp B+ than I wanted due to the 8mA + that it draws.
I opted for a 12AT7 instead which is a nice compromise. It's noise free and appears pretty tranparent with an OD or Wah.
Can't really test it properly though as I don't own a proper loop type pedal at the moment. 
If it's still not perfect when using a delay/chorus etc. I'll go back to the 12AU7 plan, but have the Loop as a sperate node in the power supply. At the moment V1 is seperate taken from the PI, and the rest are all dropped in series from the PI supply.

Thanks very much for your input, mate.


Amp update: Everything is finished now, clean channel and switching. Clean sounds great at low volume, switching is clean and absolutley zero pops so I'm delighted. My daughter has the chicken pox and she doesn't like when daddy plays his amp too loud so I'll have to wait a few more days to crank it and make some proper clips for you guys.


----------



## solarburn

Hope your daughter gets to feeling better soon. Look forward to hearing this new amp!


----------



## Wilder Amplification

PaoloJM said:


> Using a 12AU7 was causing a larger voltage in the preamp B+ than I wanted due to the 8mA + that it draws.
> I



With a preamp tube drawing current like that, wouldn't it cause a LOWER voltage in the preamp B+ due to the extra current draw creating more of a voltage drop across the power supply decoupler resistors?


----------



## Joey Voltage

Wilder Amplification said:


> With a preamp tube drawing current like that, wouldn't it cause a LOWER voltage in the preamp B+ due to the extra current draw creating more of a voltage drop across the power supply decoupler resistors?



I think he just forgot to put the word drop in there, although the 12AT7 is a high current valve as well.


----------



## Wilder Amplification

Joey Voltage said:


> I think he just forgot to put the word drop in there, although the 12AT7 is a high current valve as well.



Ah LOL...I didn't even think about that but I see it now.

Funny how you forget one word and it becomes a completely different sentence...or the words where you change one letter in the word and it becomes a completely different word.

Hell...rearrange the first and last letters in the word "this" and you've got "shit".


----------



## PaoloJM

Joey's right, forgot the word drop. Post edited now.

The new 12AT7 cathode following buffer will drawn 4.5mA instead of the 8mA of the VW 12AU7 version.
Still plent of current to make for a noise-free, hopefully non tone sucking loop,
and less voltage drop across the decoupling resistors. Yielding me an extra 40Vdc ish for V3 and V2.
As Tesco says "every little helps".


Hey Wilder, see how close G is to T on your keyboard? Heard a story recently where a guy signed off a business letter to the director of some company and closed it with the words 

_Kind Retards,
His company name (whatever it was)_


----------



## Wilder Amplification

PaoloJM said:


> Joey's right, forgot the word drop. Post edited now.
> 
> The new 12AT7 cathode following buffer will drawn 4.5mA instead of the 8mA of the VW 12AU7 version.
> Still plent of current to make for a noise-free, hopefully non tone sucking loop,
> and less voltage drop across the decoupling resistors. Yielding me an extra 40Vdc ish for V3 and V2.
> As Tesco says "every little helps".
> 
> 
> Hey Wilder, see how close G is to T on your keyboard? Heard a story recently where a guy signed off a business letter to the director of some company and closed it with the words
> 
> _Kind Retards,
> His company name (whatever it was)_



LOL now that's funny shit. Ain't spelling, grammar and semantics a bitch?


----------



## Joey Voltage

PaoloJM said:


> The new 12AT7 cathode following buffer will drawn 4.5mA instead of the 8mA of the VW 12AU7 version.
> Still plent of current to make for a noise-free, hopefully non tone sucking loop,
> and less voltage drop across the decoupling resistors. Yielding me an extra 40Vdc ish for V3 and V2.
> As Tesco says "every little helps".



12AT7's are fine so long as you don't clip them, AT7's sound terrible when clipped. thats what I'm using currently in the loop I sent you, (although it was designed for the 12DW7, I just didn't have one) and there is no change in tone other than what the Effect affects (I may even post a clip of it).

a parallel feed from the PI node would still drop the PI node by the same amount, and consequently the preamp supply with it, but you would be able to better compensate this with a parallel feed. what are your supply voltages currently?


----------



## Joey Voltage

Here, here is a demonstration using the same loop I gave you with a 12AT7, doesn't do shit to the soundso long as you don't clip the AT's. the amp is up louder than it seems, but you can still here the pick. Not really meant to be a hijack but more of a thumbs up-do 1t, it works vote of confidence! type of thing.

[ame=http://www.youtube.com/watch?v=vfWxHtQOmWI]YouTube - MOV03009.MPG[/ame]


----------



## rads

a bit change, to the mid-treble freq i guess. 
I'm listening via earplug. The tone when loop was on was a bit duller.

Btw, can i use this in JCM800 2204???
Or kurts effect loop still does better???


----------



## solarburn

I listened to it with my good plugs too and you can here a difference but I bet it doesn't translate to much live...

joey you feel any loss of subtle dynamics at all? If not I would find it a non-issue what bit of change there is.


----------



## PaoloJM

Joey Voltage said:


> Here, here is a demonstration using the same loop I gave you with a 12AT7, doesn't do shit to the soundso long as you don't clip the AT's. the amp is up louder than it seems, but you can still here the pick. Not really meant to be a hijack but more of a thumbs up-do 1t, it works vote of confidence! type of thing.
> 
> YouTube - MOV03009.MPG



Hey man, good demo, thanks.
What exactly are looking at here? What is the unit you're switching? It looks like some rack gear from the vid.
I can also hear a roll off in the highs but it's quite subtle and not what I'd call tone sucking. 
My loop is non-switchable series type so there's no by-pass to compare too. Might install a foot-switch at some point, my regulated LV supply (7806) is only drawing 340mA of a potential 1 amp, it's heat-sinked to the chassis and doesn't even get warm at the moment.
Thanks again for the demo.

PS: Is that the riff from Wonder Boy?


----------



## Wilder Amplification

PaoloJM said:


> What exactly are looking at here?



I thought we were listening...not looking



PaoloJM said:


> What is the unit you're switching?



Are you really concerned with his "unit"?



PaoloJM said:


> I can also hear a roll off in the highs but it's quite subtle and not what I'd call tone sucking.



Define "tone sucking"




PaoloJM said:


> PS: Is that the riff from Wonder Boy?



To me it sounded like a bad attempt at "The Way It is" by Tesla (he left out the "high E string ring")


----------



## PaoloJM

Wilder Amplification said:


> I thought we were listening...not looking
> 
> 
> 
> Are you really concerned with his "unit"?
> 
> 
> 
> Define "tone sucking"
> 
> 
> 
> 
> To me it sounded like a bad attempt at "The Way It is" by Tesla (he left out the "high E string ring")



We were listening, noticed asmall amount of high end roll off and then wondered what exactly the set up was, as there may be factors other than the loop itself causing this effect.

I'm sure Joey has a fine "unit" but I was more enquiring about the thing he was switching in this video. 

My definition of tone sucking would be anything that significantly/noticeably effects/affects (which is fucking which? ) the tone adversely. Most people seem to use it for when the high end gets rolled off, but I'd also use it if the bottom gets pulled or goes flubby or if the midz get sucked out (unless of course that's what you actually wanted).


[ame=http://www.youtube.com/watch?v=lHY5L47tcHk]YouTube - Tenacious D-Wonderboy[/ame]

Damn must be breaking copyright by trying to link that vid.


----------



## Joey Voltage

The perceived roll off in highs on the camera is due to the effect, they are still there, trust me my ears wanted to bleed, The patch I had has multiple delays, reverb and a detune effect so it is bouncing that sound all over the room, which is not exactly dry to begin with, and the camera is picking it up. It's doing exactly what I would expect a chorus, multi-delay,and reverb to do really. 

The unit is an eventide H-3000se

And no don't getall excited LOL it is not an attempt at tenacious or tesla, (I don't think I know songs by either) or any song really, just an impromptu progression..... a DMaj progression with the borrowed chords BbMaj, and C, Aeolian, countless bands use all the time in various ways. Something I knew I could play and flip the switch atthe same time really.


----------



## Wilder Amplification

Joey Voltage said:


> The perceived roll off in highs on the camera is due to the effect, they are still there, trust me my ears wanted to bleed, The patch I had has multiple delays, reverb and a detune effect so it is bouncing that sound all over the room, which is not exactly dry to begin with, and the camera is picking it up. It's doing exactly what I would expect a chorus, multi-delay,and reverb to do really.
> 
> The unit is an eventide H-3000se
> 
> And no don't getall excited LOL it is not an attempt at tenacious or tesla, (I don't think I know songs by either) or any song really, just an impromptu progression..... a DMaj progression with the borrowed chords BbMaj, and C, Aeolian, countless bands use all the time in various ways. Something I knew I could play and flip the switch atthe same time really.



LOL...had to bust your balls on that one a bit. You gotta admit it does sound kinda like that shit.

On that perceived roll off in the highs...are you sure that's not due to the solid shielded titanium wire you used in the amp you're playing through? Or maybe it was those NOS carbon comp resistors you used?


----------



## solarburn

Wilder Amplification said:


> LOL...had to bust your balls on that one a bit. You gotta admit it does sound kinda like that shit.
> 
> On that perceived roll off in the highs...are you sure that's not due to the solid shielded titanium wire you used in the amp you're playing through? Or maybe it was those NOS carbon comp resistors you used?



I thought it was due to switching the loop on and off.

Could have been them time based effects swirling in and out at the same moment...I guess...


----------



## Joey Voltage

Wilder Amplification said:


> LOL...had to bust your balls on that one a bit. You gotta admit it does sound kinda like that shit.



I haven't heard that song for 12 years, I guess I have to go check it out now. EDIT: i listened to it, way more Zeppelin sounding than I was thinking



Wilder Amplification said:


> On that perceived roll off in the highs...are you sure that's not due to the solid shielded titanium wire you used in the amp you're playing through? Or maybe it was those NOS carbon comp resistors you used?



Yeah Yeah Yeah Sozo boy! maybe it the piece of coaax between my MV, and PI


----------



## Joey Voltage

solarburnDSL50 said:


> Could have been them time based effects swirling in and out at the same moment...I guess...



Might justbe better to do an effect rather than 4 or 5 together I guess.


----------



## Joey Voltage

PaoloJM said:


> My definition of tone sucking would be anything that significantly/noticeably effects/affects (which is fucking which? ) the tone adversely. Most people seem to use it for when the high end gets rolled off, but I'd also use it if the bottom gets pulled or goes flubby or if the midz get sucked out (unless of course that's what you actually wanted).



To me tone sucking in a loop is significant loss of treble and volume, although what you said about the bass and clarity also stands up. 

although it gets a little seedy here, as some effects by nature (or the quality of) will naturally do this most analogue (and some digital) Choruses... maybe most time based effects for example will do this somewhat regardless of how good the loop is by nature, and what they do. so it boils down to whether or not it is an adverse change that is the key like you said. and if you really hated to alter the sound somewhat, why the hell would you use the effect in the first place.


----------



## PaoloJM

Joey Voltage said:


> To me tone sucking in a loop is significant loss of treble and volume, although what you said about the bass and clarity also stands up.
> 
> although it gets a little seedy here, as some effects by nature (or the quality of) will naturally do this most analogue (and some digital) Choruses... maybe most time based effects for example will do this somewhat regardless of how good the loop is by nature, and what they do. so it boils down to whether or not it is an adverse change that is the key like you said. and if you really hated to alter the sound somewhat, why the hell would you use the effect in the first place.



Agreed totally. That's why I was asking what the exact set up was.
Was afraid originally that it just the loop by-pass, with nothing in the loop itself, that you were switching. 
Any analog effect will be darker in tone, that's why people love/hate them. Not to mention 4 to 5 of them being a bit darker.
I've a MXR Carbon Copy and 10 band graphic come the loop this week so I'll be able to see how mine performs.

The little one is feeling much better so I'll be able to record decent clips of the complete amp this week. I'll probably do a uTube running through all the features and then post a few SoundClips of specific tones recorded with a mic.
It'll still be in tweaking phase as I haven't done any real decent volume testing yet.


----------



## Wilder Amplification

PaoloJM said:


> The little one is feeling much better so I'll be able to record decent clips of the complete amp this week. I'll probably do a uTube running through all the features and then post a few SoundClips of specific tones recorded with a mic.
> It'll still be in tweaking phase as I haven't done any real decent volume testing yet.



Make sure that when you do the A/B clips between carbon comp and carbon film resistors that you turn the camera mic off axis slightly on one of the vids so that we'll actually hear a tone difference between the two.


----------



## PaoloJM

Wilder Amplification said:


> Make sure that when you do the A/B clips between carbon comp and carbon film resistors that you turn the camera mic off axis slightly on one of the vids so that we'll actually hear a tone difference between the two.



Mines got the straight up metal film mode too!!
That gives teh real brootz towanz.


----------



## Wilder Amplification

PaoloJM said:


> Mines got the straight up metal film mode too!!
> That gives teh real brootz towanz.



We need to hear some real Irish rock through that thing...some Fastway perhaps?


----------



## PaoloJM

Wilder Amplification said:


> We need to hear some real Irish rock through that thing...some Fastway perhaps?




Thought those guys were brittish? 
Maybe some Lizzy or Kerbdog...we're kinda limited for good heavy rock here.
Not sure how a banjo, bodhran or fiddle would sound through it...might have play some brit/american stuff too.


----------



## Wilder Amplification

PaoloJM said:


> Thought those guys were brittish?
> Maybe some Lizzy or Kerbdog...we're kinda limited for good heavy rock here.
> Not sure how a banjo, bodhran or fiddle would sound through it...might have play some brit/american stuff too.



Everyone but the singer is. David King is from Ireland.

Believe it or not...he is now the founder/frontman for the Celtic punk band Flogging Molly.


----------



## MajorNut1967

Wilder Amplification said:


> Celtic punk band Flogging Molly.



Sounds like an old girlfriend or something!


----------



## Joey Voltage

Wilder Amplification said:


> Make sure that when you do the A/B clips between carbon comp and carbon film resistors that you turn the camera mic off axis slightly on one of the vids so that we'll actually hear a tone difference between the two.



Nah dude that was two different carbon films! LOL


----------



## Joey Voltage

PaoloJM said:


> Thought those guys were brittish?
> Maybe some Lizzy or Kerbdog...we're kinda limited for good heavy rock here.
> Not sure how a banjo, bodhran or fiddle would sound through it...might have play some brit/american stuff too.



I dunno man, you guys have some pretty good native Rock guitar players that came from there though. John Sykes, Gary Moore, Vivian Campbell etc... and a lot of the brittish rock bands have a few of you integrated... Scotts too.


----------



## PaoloJM

Joey Voltage said:


> I dunno man, you guys have some pretty good native Rock guitar players that came from there though. John Sykes, Gary Moore, Vivian Campbell etc... and a lot of the brittish rock bands have a few of you integrated... Scotts too.



Yup, must do some more research and my Irish bros.
Don't forget that I'm still in my 20s, I'm not up with all the old fogeys!!

Well, as mentioned, the little one is better so here's the clip.

I recorded it at reasonable volume with the digital camera and so it clips and compressed/pumps quite a bit.

I dialed in a glassy type clean and brootz type dirty just to show the amp functions.
I'm using my standard Marshall channel/reverb foot-switch for the channel switching and solo boosting, though the solo in the vid here just compresses even more!! 
That's my crappy old squire strat with hum-bucker bridge as I wanted to really test out the noise levels.

[ame]http://www.youtube.com/watch?v=3GSw3vt823k[/ame]

What do you think?
LEDs too much?
How's the tones?
Noises levels, channel switching pop? I think they're pretty good tbh, I can't hear any channel switch noise other than the mechanical noise of the floor-switch itself.

I promise I will make proper SM57 -> protools unedited recording later in the week.


----------



## solarburn

Tones sounds great. OD side is really thick and defined. I have to remind myself this is a 50 watter and not a 100. Lots of oomph! Can it do mid gain stuff or is this just a ball kicker? That was quite a difference in character going from the nice clean to that high gain setting all at once.LOL


----------



## Wilder Amplification

PaoloJM said:


> I dialed in a glassy type clean and brootz type dirty just to show the amp functions.



It's "brootlz" bruah!


----------



## Procter2812

PaoloJM said:


> Yup, must do some more research and my Irish bros.
> Don't forget that I'm still in my 20s, I'm not up with all the old fogeys!!
> 
> Well, as mentioned, the little one is better so here's the clip.
> 
> I recorded it at reasonable volume with the digital camera and so it clips and compressed/pumps quite a bit.
> 
> I dialed in a glassy type clean and brootz type dirty just to show the amp functions.
> I'm using my standard Marshall channel/reverb foot-switch for the channel switching and solo boosting, though the solo in the vid here just compresses even more!!
> That's my crappy old squire strat with hum-bucker bridge as I wanted to really test out the noise levels.
> 
> YouTube - 50 Watt amp demo 2
> 
> What do you think?
> LEDs too much?
> How's the tones?
> Noises levels, channel switching pop? I think they're pretty good tbh, I can't hear any channel switch noise other than the mechanical noise of the floor-switch itself.
> 
> I promise I will make proper SM57 -> protools unedited recording later in the week.



mate that sounds awesome.. can i have one?


----------



## PaoloJM

solarburnDSL50 said:


> Tones sounds great. OD side is really thick and defined. I have to remind myself this is a 50 watter and not a 100. Lots of oomph! Can it do mid gain stuff or is this just a ball kicker? That was quite a difference in character going from the nice clean to that high gain setting all at once.LOL



Cheers, mate.

The clip below is using a Les Paul in standard and less gain.



Procter2812 said:


> mate that sounds awesome.. can i have one?



You'll need a lot of money!! 
Thanks for the comment.






Here's my latest soundclip.
I'm going for more "classic" tones here. 
I'm using my Les Paul in standard tuning, there's a carbon copy and MXR EQ in the loop and a boss OD up front.
I'm just switching channel and FX and playing whatever came into my head.

I set up the EQ to do more of that Mesa tone. It's pushed @ 120Hz, scooped a little @ 500 and 1k and pushed a little @ 6k and 8k for that snarl.

Again it's low volume digital camera but I will definitely be making miked clips next week.

[ame]http://www.youtube.com/watch?v=TH37ZstzXnU[/ame]

Let me know whatcha think tone wise.


----------



## jcmjmp

Is that the bridge pickup the whole time? It sounds like some of it is neck and some is bridge. There are tone differences I hear.... are those just different modes on the amp?

The basic tones are nice. Hard to tell from a youtube clip.


----------



## PaoloJM

jcmjmp said:


> Is that the bridge pickup the whole time? It sounds like some of it is neck and some is bridge. There are tone differences I hear.... are those just different modes on the amp?
> 
> The basic tones are nice. Hard to tell from a youtube clip.



The only function on the amp being switched here is the channel control.
The chain is Les Paul => Dunlop Wah => Polytune => Boss SD2 => Amp => Send to MXR EQ => Carbon Copy => Return => 2X12 with G12H and V30

The sequence of the video follows roughly:
Neck pickup with no FX
Neck with carbon copy set on modulation for a kind of mild chorus
Neck with carbon copy on dirty channel
Bridge on dirty with no FX
Bridge on dirty with a clean boost from Boss SD2
Bridge on dirty with clean boost and EQ set with pushed lows and highs
Same as above with the carbon copy


The MXR 108 is also an amazing pedal.
I was playing it last night in front of my JCM800. 
It really allows you to sculpt the tone. You can bring more lows without adding muddy low mids. Coax more upper mids if you want. 
I was setting it to compensate for the Fletcher Munson (sp?) curve, used a pretty clean boost, and it is very convincing for bedroom levels.
It'll also be a useful tool for figuring out mods I think.
It's extremely powerful and highly recommended.

Next week will definitely bring the miked clips of the amp.
I'll accompany each clip with the amp and FX (if any) settings.


----------



## PaoloJM

Finally.....


Here's a link to sound-click where I've uploaded a few miked up tone clips.

http://www.soundclick.com/bands/default.cfm?bandID=1067692

There's some clean, OD and heavier tones.
I'm use my Les Paul throughout.
Everything is recorded straight with SM57 => MBox => ProTools LE and there's a touch of reverb on each track.
My recording skills aren't great but you should get the picture.

The cleans and pushed clean are using the vintage supply mode and the rest are using the modern one.

Again input, thoughts and criticisms would be appreciated.


----------



## PaoloJM

Set up a Netmusicians to direct link the clips.

Clean

Pushed clean

Mid gain

Higher gain


----------



## thrawn86

Likey likey. I just listened to the two Youtube vids......the Strat sounded a bit 'tinney' on the clean, but when distorted it went away. I know it's because of the camera because the LP didn't have the same problem. Sounds great.


----------



## PaoloJM

thrawn86 said:


> Likey likey. I just listened to the two Youtube vids......the Strat sounded a bit 'tinney' on the clean, but when distorted it went away. I know it's because of the camera because the LP didn't have the same problem. Sounds great.



Cheers man, I'll have more clips to post soon.
I'm gonna spend more time getting specific tones like thrash metal, blues, classic rock etc.


----------



## TwinACStacks

PaoloJM said:


> Thought those guys were brittish?
> Maybe some Lizzy or Kerbdog...we're kinda limited for good heavy rock here.
> Not sure how a banjo, bodhran or fiddle would sound through it...might have play some brit/american stuff too.



 Yeah But Nazareth live just a Tad bit to your East....

BTW: the clips sound awesome Paolo.

 TWIN


----------

