My new amp...let's wreck it

[SILVERGUN]

OK, so I built an amp...after weeks of gathering parts, preparing a layout, drilling and cutting aluminum, and investing somewhere in the area of 182 hours,,, I am the proud father of a bouncing baby Trainwreck Express type (I didn't use the EXACT schematic or layout)......I really had no idea that there was a community dedicated to these things,,,,I saw the video with Glen and the interview with Ken, and I was moved to make THIS amp.
So I pluged it in, had a few minor problems, solved them (I'll discuss more later)....and now I have an amp that works great as-is but isn't really what "I" was looking for........here's pre-build info:http://www.el34world.com/Forum/index.php?topic=14476.
So let's do something about it...I'm going to be trying a few modifications in the coming weeks and I'll try to document them here...my goal would be to share EVERYTHING I have done, and will do, and get some sound clips up so you guys can get the feel for whats happening here.
The amp sounds great, especially cranked, but is very stiff and not very forgiving...

***DISCLAIMER***- I am not trying to build a Trainwreck Express "CLONE"...I'm trying to tweak the circuit to my tastes, and don't really have time to worry about NOS tubes, specific OT's, pre-rola Celestion's, specific capacitor/resistor types, exact layout, blah, blah, blah, blah, blah....thank you in advance for your concern, but I'm just not "that guy"
I built a nice clean circuit and it should and will sound like I want it to.....in fact I'm not going to call it a TW Express......I'l call it SG#001 or just 001

I'm trying to build an overdrive machine, with no external boost/OD/dist. pedal needed to get max OD....cleans are secondary, and the ones I'm am getting are totally acceptable....very nice actually.....the version of the schematic I used, was described as being a very mean, so I thought OK, I'll do this one....got it all wired up, and plugged in and thought "is that it?",,,, so I guess I'm spoiled, but that's the cool part of this, we can change it.

The first issue I had was a high pitch squeal which was easy to find, and the result of an obvious rookie mistake:
SOLUTION: I took the 820M "grid stopper" off the board and used a shielded wire right from the vol. pot to the resistor that I mounted on the tube socket pin....DUH!.....quite as can be now

Then I had another high pitched squeal coming from the NFB circuit if the Presence control was set to 2 or below only.
SOLUTION: I inserted a 250K pot in place of the NFB resistor and dialed in a sweetspot at 68K......replaced the stock 100K with a 68K resistor and not only did it respond better, but the Presence control squeal was gone.......the only problem with that solution was I had also reversed the OT wires during the same session, so I'm not really sure which fix solved the noise problem,,,,but, its definitely gone and the OT wires are in the right spots now

I also experimented with a pot in the PI tail resistor location, and "think" I dialed in a sweetspot of 56K
SOLUTION: I replaced the tail resistor stock value of 10K with the new 56K value  (anybody see a potential problem there?)

If you want to see anything that I haven't posted yet,,,just ask

If this hurricane doesn't blow the roof off of my house I'll try to get something recorded later this week.

THANKS to everyone for your support and guidance so far....YOU GUYS have helped to make this happen!

[stratele52]

Very nice amp . enjoy it.

[phsyconoodler]

Nice lkooking build! Well done!

I like using a PI plate trimmer to balance the PI.I used one in a recent D style build and it is absolutely the S**T ! I can dial in serious tones.

[tubenit]

I'm going to be trying a few modifications in the coming weeks and I'll try to document them here...my goal would be to share EVERYTHING

OK, great!  IF you want to really do that ............. here is a schematic that you can alter to share what you've done.  I drew it up for you just for that reason alone. You'll need ExpressSCH to modify it.

 

With respect, Tubenit

[TubeGeek]

Nice work!

Looks great

[cbass]

Looks great what schematic are you using?

[SILVERGUN]

Thanks for the kind words guys....
Jeff, I have been inspired by your generous work here and hope to share what I have done and get help with tweaking the circuit to my taste....please bear with me  while I learn how to use the Express SCH program

I'm currently trying to live through a hurricane and expect power to go out soon....real soon...winds are gusting to 60mph right now

cbass, here's the exact schematic I used, and I tried to stay as close as possible:

[cbass]

Not sure where that schematic came from but its got a lot of changes from what I know as an express.

[tubenit]

while I learn how to use the Express SCH program

It's incredibly intuitive.  

You can click on components and change the values of the components.  

You can click on entire sections like a triode, LTPI, power rail, tone stack ................ etc....... and save an entire area. I have saved entire preamps, OD sections, reverbs, active FX loops,  phase invertors, PT with power rails, tone stacks ............... and so on.

You can go into the "original library of components"  (that comes with the program)  and save the parts that you need like resistors, caps, filter caps, transformers, speaker, diodes, zeners, potentiometers,  etc.............. all into a "FAVORITES" library.

They don't have a triode or pentode tube in the library of components, so I suggest you save the ones in the schematic I drew. Or draw up your own.

Almost any schematic you see me post is simply one I grabbed out of the Hoffman SCH Library of schematics and just altered.  
That's how I come up with them so quick.  This Trainwreck was a single channel AB763 about 10 min before I altered it.

BTW, the schematic I drew is the one you referenced.  They're pretty much the same.  

With respect, Tubenit

[TIMBO]

Nice work Mr. Gun, Learning how to draw the schems is a must, makes it so much easier to see whats going on. I actually find it relaxing and when you find other circuits it is some times challanging to be able to link them all tohether.

"But isn't really what i was looking for" I'm hearing ya, I'm sure Tubenit & Co. must have a mountain of half built and rebuilt amp under there belts, I just copped it from the wife (after moving house)about the half built amps that i've got in the stashed in the cupboard.

But thats the drug where addicted too.Happy TWEAKING. 

[jojokeo]

Lookin good Dave. Replace that 56k w/ a 150k or even >220k and you'll get more gain going into that last stage for more of what you're looking for. Also, a "true" wreck clone should have the Presence pot mounted further from the rest by itself, LOL! ;)  Seriously, disenguage the thing (NFB/presence) temporarily and you'll see an improvement for more gain here too. You can get a switched or push-pull pot later on if you want. Anways, two quick & easy things to get more grind & gain going for ya. Good luck on the Storm passing by - did you put lamb's blood on your front door?

[kagliostro]

Cool 

K

[stratele52]

I'm going to be trying a few modifications in the coming weeks and I'll try to document them here...my goal would be to share EVERYTHING

OK, great!  IF you want to really do that ............. here is a schematic that you can alter to share what you've done.  I drew it up for you just for that reason alone. You'll need ExpressSCH to modify it.

 

With respect, Tubenit

Great schematic you sketch Tubenit, I should learn to ExpressSCH .To bad it is not for Mac . I should use my old PC

[cbass]

Also keep in mind this circuit is prone to ultrasonic osicilations.If you have that going it won't sound very good.
Hows it clean up when you back the guitar vol. down?if its bright and jangly.You are probaly ok.

Hope the hurricane didn't hit ya to hard.

[cbass]

If you are still having problems with the prescence circuit.Try mounting the NFB resistor right on the pot.Then you can experiment with placement of the NFB wire for the most stable spot.I'd run it right under the end of your turret board

[SILVERGUN]

Thanks a lot guys.... woke up this morning and the roof is still on the house so we're okay.... running on generator power and there's no power at work... that's where the amp is.... I'll get back in there tomorrow and fire up the soldering iron

[thelonious]

Great schematic you sketch Tubenit, I should learn to ExpressSCH .To bad it is not for Mac . I should use my old PC

stratele52, old PC for ExpressSCH should work just fine, but if you want a Mac program you can try JSchem (http://dhost.info/jschem/). It opens SCH files, but will only save to JSCH. I like it just as much as ExpressSCH and use it on my Mac.

[SILVERGUN]

OK...power is back on and I'm not at work so I had some time to mess with ExpressSCH....the first thing I did was adjust any incorrect values, or values I have changed, to bring it up to date.......and you were right Jeff, it's very easy to use......
In the Paint version I have included an idea for a first real modification, to utilize the unused triode V2b....I can't stand to see those 3 pins with no wires going to them,,,especially if I'm asking for more gain......let me know if there is a "better" idea than the cathode follower....also let me know that my drawing is correct/incorrect
Took a minute to cut and paste some stuff in Paint so that guys that aren't using E SCH can join in:

**UPDATE**- this master volume idea was a horrible waste of time , but I'll leave it up for reference

[SILVERGUN]

Not sure where that schematic came from but its got a lot of changes from what I know as an express.

Schematic came from page 7 of this PDF: (kinda cool because there are a couple nice variations to try there)

Only problem is that his idea of the meanest amp is not the same as mine....

Presence circuit is OK now, and clean sounds are really good, and definitely get better as you decrease guitar vol.

[SILVERGUN]

a "true" wreck clone should have the Presence pot mounted further from the rest by itself, LOL! ;)

I knew I could count on you to lighten this up.....yeah, I left the knob off in hopes that I wouldn't insult anyone
 

[SILVERGUN]

Spent a little more time and was able to transcribe Paint jpeg to SCH file, which now includes possible mod1...
Let me know what you think tubenit.......it takes a little getting used to, but very cool FREE program....at least this way we're carving the same type pictures into the cave walls

[tubenit]

OK,  let me toss out some thoughts and observations and considerations.

The Trainwreck has two fairly high gain stages going into a more "relaxed" 3rd triode with no cathode cap & with lower gain PLUS a grid resistor dropping volume in front of that.  Note that the Trainwreck uses 22uf cathode caps on those first two gain stages.

So you kind of have two very cranked gain stages into a very low gain stage.

The Dumblish amps use 4 moderate gain stages in series.

In contrast to that, the Dumblish amps tend to use 5uf caps (or maybe 10uf on a few models) in those first two gain stages going into OD stages also with 5uf caps.  In the OD stage, the coupling caps are reasonably small.  I also have seen a BadCat type preamp and OD schematic that had some low cathode cap values & low coupling cap values between gain stages.

I think you will find a very difficult time getting a clear non-muddy tone by adding another gain stage with those first two cathodes having 22uf caps.  That's my unscientific opinion from experimenting. I think you'll get grit and grind but will lack a sweet musical harmonic tone.

I think the cathode follower that you've added will change the original tone but will not increase the gain at all.  That's my guess. Having said that,  I built a Double C amp for a friend sort of doing what you are doing.  A triode into a triode into an OD stage with a triode with a cathode follower  (this Double C amp is in the ExpressSCH Library for you to look at)

So in my thinking, IF you actually want to increase the gain by adding another triode gain stage,  I think you're going to have to significantly lower the cathode cap values on V1-3 & V1-8.   You might be able to use 10uf on V1-3, then 5uf on V1-8  & then add something like the Dumblish OD section with 5uf or 2.2uf cathode caps. 

I also think you'll need to lower the .1 coupling cap into the LTPI to a lower value like .002 to .01 range.

Anyhow, those are some of my thoughts.  My guess is the 22uf caps will just give you high gain mud IF you add a triode gain stage and don't lower the 22uf values. And too high of coupling cap values in the OD stage will give you mud also, IMO. 

With respect, Tubenit

[tubenit]

I want you to take a close look at these 3 different high gain preamps (& OD).

What do you notice about the size of the coupling caps between stages?

What do you notice about how volume/gain is dropped by resistors and/or pots between stages?

What do you notice about the size of the coupling caps with 3 gain stage amps compared to 4 gain stage amps?

Ponder that ............. and then post what stands out to you about increasing gain on amps with varying gain stages.

Remember ........... IF you really aren't going for a Trainwreck amp tone but simply want a GREAT amp tone that is actually perhaps
innovative and cool sounding .............. you have alot of options to consider to make this your own design. (sort of)

With respect, Tubenit

[SILVERGUN]

OK,  let me toss out some thoughts and observations and considerations.

Thanks buddy,,,that's what I'm looking for....I appreciate you taking the time to guide me
I'm definitely into the Dumble stuff and will evetually head in that direction 100%

I'll start slow and try to document everything and hopefully get some recording done at each stage of mod. so you'll be able to hear what we're doing.....there's only one big problem that I'll try to fix in the next week,,,I don't really have any good speakers..I sold my 4x12 w/ vint.30s and haven't replaced it so what you hear will be coming out of some cheapo Celestions I have laying around...I figure that if I can get a decent sound out of those, then it should sound great with some new G12H 30's or something like that

[SILVERGUN]

What do you notice about the size of the coupling caps between stages?

What do you notice about how volume/gain is dropped by resistors and/or pots between stages?

What do you notice about the size of the coupling caps with 3 gain stage amps compared to 4 gain stage amps?

I printed that out and will be staring at it for the next 1/2 hour.....
This is the part that I really NEED to understand....I know that.
Coming from welding machine repair, I thought this stuff would be easier, but with tube amp circuits, it seems like the more I learn, the more I need to learn.....in my spare time I'm still trying to digest IMPEDANCE

[tubenit]

OK,  .......... just to continue to stir your thinking (and I am NOT handing you a script ........... strictly to get you to think creatively).......

Again, I am keying off your idea of a high gain amp that doesn't have to sound like a Trainwreck but that sounds really good.

IF I was given the task of trying to have 3 gain stages that were clear OD tone and NOT muddy,  I might consider something like this.

1)  paralleled V1 triode for 30% more gain with no floor noise increase
2)  very low insertion loss tone stack
3)  a 250k trim pot instead of 56k resistor to ground
4)  switchable NFB on/off
5)  you will have to experiment with coupling cap values and cathode cap values where I show a range to consider. I would NOT use any
     cathode cap above 10uf. I personally would try the lower indicated values first and then increase IF needed.
6)  250p  smoothing cap
7)  120p enhance cap on the LTPI plate resistor
8)  I think there is a chance the volume pot would need to be lowered from 1M to 500ka


Again, I am not suggesting that you build this but thought I'd toss it out to demonstrate something a little outside the box that might sound pretty cool.  So I'm not trying to give you an amp design but instead inspire you to think creatively but with reason based on observing what others have done successfully.

So IF you came up with something like this that sounded great, then you'd have something that would be pretty unique.  I've looked at ALOT of schematics and haven't seen anything that had this same topology and approach.

With respect, Tubenit

[cbass]

I think jojo meant the change the 56k resistor on the third gain stage going from the grid to ground.

[SILVERGUN]

I think jojo meant the change the 56k resistor on the third gain stage going from the grid to ground.

Thanks cbass, I'll check with jojo on that one....it does seem like an awfully high value for that PI position

I obviously have some more reading to do...

Ahhh yes, I see it now....he say's "going into that last gain stage"........rookie

I went back and fixed the jpeg, hopefully before anyone else saw it

[SILVERGUN]

OK,  .......... just to continue to stir your thinking (and I am NOT handing you a script ........... strictly to get you to think creatively).......

Again, I am keying off your idea of a high gain amp that doesn't have to sound like a Trainwreck but that sounds really good.

Great stuff there T,
I am going to have to do some more reading so I can catch up.....this is not a one time fling for me at all and I really must understand this stuff to move forward...

I don't care at all about keeping the TW circuit in tact other than keeping the one aspect that I did fall in love with which is the amps tendency to jump into harmonic feedback very easily when cranked (mine does do that)...it was my understanding that the higher value bypass caps in the first 2 stages were partially responsible for that,,,,and if I have to live with a little mud- that's ok
BUT, that's not saying I'm not listening.....I WILL try lower values in both positions, one at a time, and record their effect
I do want to keep it a simple circuit, and it really doesn't sound BAD as-is, I just want it to sound more bad-ass
I'm interested in learning, and the good news is, I am not in a hurry to have a completed amp.

The minute I "finished" this amp and plugged in,,,I knew it wasn't finished

Thank you so much for your help

[tubenit]

OK,  a couple more simple ideas to try.

1)  PAB (preamp boost) - try simply disconnecting the bass to treble pot connection, if you like that  put a mini-toggle there

2)  try a .03 cap for the mid cap in the tone stack.  Simply use insulated alligator clipped wires to parallel a .01 w/.03.  I find the .03
     reduces some mid tones that make an amp sound muddy.

3)  try reducing the .1 cap into the LTPI to .047 or .02.   Unsolder one end and "clip in" a .047 or .02

4)  add smoothing cap and especially the enhance cap  (82p- 120p range)   Again you can (SAFELY) clip on those caps and try them

5)  undo one end of the 22uf cathode caps and clip in 10uf on the V1       Clip in a 10uf or 5uf on the second gain stage

6)  reduce 47k to 33k or 27k input resistor

7)  paralleled triodes in V1

8)  you can try a 68k slope resistor which will increase gain. You can clip in a paralleled 330k to get a 76k value there and try that

9)  clip in a paralleled 82p - 180p range cap across the 500p treble cap. This definitely
     will give you a gain/overdrive increase

Easy things to try in an effort to improve tone and/or increase gain.  Keep working with the amp until you get a  "WOW" factor going.

With respect, Tubenit

[SILVERGUN]

I would really like to start with a master volume because my old ears cant handle the volumes that this thing sounds best at...
What do you think of my original mod for the cathode follower master?.....how about that cap value I inserted?

Do you consider a master vol. a LAST step once you have the amp "voiced"?

[cbass]

heres some ideas you could try.

[tubenit]

I would really like to start with a master volume because my old ears cant handle the volumes that this thing sounds best at...
What do you think of my original mod for the cathode follower master?.....how about that cap value I inserted?

I would be inclined to try a PPIMV master volume, but what you have there is OK if you like it?  The PPIMV would allow the phase invertor to still be "cranked" and (I think) do a better job at preserving the high gain tone.

The CF is fine & I think it will simply change the tone and do nothing significant for gain.  Try anything from .001 to .01.  I'd probably start with .0047.

With respect, Tubenit

[SILVERGUN]

heres some ideas you could try.

Thanks again cbass, I cant open that file with E SCH

[cbass]

Sorry I have know idea on how to change the file type.

[cbass]

I would recommend the ppimv also.Really an attenuator is the best way to tame these amps.Some folks like vvr but I've never tried it.

I think you can see it now.I tried to make the values red where there are changes.I added a high cut control and a fast gradual switch like on the comets.I find them very useful however YMMV.The CF doesn't add any gain in this situation. But it causes compression I think

[darkbluemurder]

The cathode follower master would cut down the signal going into the phase inverter (PI) so that both PI and the power tubes operate in the cleaner range. The PPIMV would allow you to cut the signal after the PI, i.e. it lets you hit the PI hard. The side effect is that the presence control will not work as well when the PPIMV is turned down, due to the fact that the feedback loop decouples if it does not get enough signal. If this bothers you, change the 5k pot to a 4k7 resistor, keep the 0.1uf cap there and add a cut control like Vox AC-30 (I learned this from Larry aka novosibir).

EDIT: cbass already posted the idea with the cut control.

Tubenit posted some very good ideas. I especially like idea no. 2.

Cheers Stephan

[SILVERGUN]

6)  reduce 47k to 33k or 27k input resistor

It feels like I'm hitting the front end extremely hard and I was considering increasing the input resistor value.?...I assume that will reduce the front end "spank" I'm getting??

I was also going to suggest to others to use low output pickups with this design....all of my stuff is high output, but I haven't tried the '57 classic+ in my LP yet

[SILVERGUN]

The CF doesn't add any gain in this situation. But it causes compression I think

That's a good thing...this thing could use a little compression....it sounds and feels very raw to me

[tubenit]

It feels like I'm hitting the front end extremely hard

I think the 22uf cathode caps contribute significantly to feeling like it's being "hit hard". At least that has been my experience. I quit using 22uf caps yrs ago. I think they made my amps sound muddy/gritty/grainy.

When I first starting building/designing amps (all the way back to the Carolina Blues Special),  I used center off spdt switchs on the V1-3 cathode with paralleled caps. I found that I preferred 2.2uf, 5uf or 10uf and consistently disliked the tone I got with 22uf caps which sounded harsh to me. I never could get the clarity on my amps that I wanted with 22uf caps. I began looking for (& found) other ways to increase gain/overdrive without increasing grit. I like smooth gain.

My guess (& I could be totally wrong) is that a 27k input resistor with a 5uf cathode cap would give great gain without a tone of sounding like it's hit hard?
And that may not be the case?

With respect, Tubenit

[SILVERGUN]

OK here's the breakdown for tonight...I'm gonna keep it simple, and keep the board as in tact as possible...
1) I'll record sound clips of the amp AS-IS
2) Experiment with lower value cath. bypass caps in both V1a+b ( I dont have many "in stock" values, so I'll have to try what I have (2.2uf maybe?)
3) I'll  increase the value of that 56K going to ground before V2a grid (i'll try a pot and see if i can dial it in)
4) Wire V2b as pictured above for a cathode follower to feed pre-PI master (save the PPIMV for later)
5) Try the PAB and install a switch if I like it
6) Clip in a 100pf cap parallel with the 500p treble cap
7) Clip in enhance cap around 82K PI plate resistor
8) Fix the incorrect wiring of my Cliff input jack
9) Record more sound clips in hopes that I improved something

Maybe not in that order, but I'll try to take my time and see what each change brings to the table....I can't say thanks enough....stay tuned
Unfortunately, I work a little slow ...amp is at work and mods don't start until 5:01 EST

[tubenit]

All of those sound like a very good plan. I look forward to hearing and hearing of the results.

Experiment with lower value cath. bypass caps in both V1a+b

IF you have limited cathode caps and values & can only lower one of those than lower V1-b. Maybe try a 2.2 in V1-b and listen. Then parallel a second 2.2uf for 4.4uf on V1-b & listen again.

With respect, Tubenit

[SILVERGUN]

On my lunch break I took some V ac-dc readings...just for the record
This is where we stand: Input is 124 vac...sec. is 340-0-340...rectified and filtered B+ 480vdc to plates(higher than I had anticipated)
470vdc to screens...-45vdc bias on pins 5....bias at idle reads 18mv, with cathode resistor method...running 2 new Tung sol 6V6 and they don't seem to be bothered by the 480v
I had some old EL 34s in there and I expected them to sound better, but they really didn't, plus they increased the clean headroom, which really isn't what I'm looking for here, I like the lower output and perfect breakup of the 6V6....plus they hurt my ears less

I experimented with a Variac on the input and took it down to 105vac input, which lowered the B+ to 410, which was my target, and I cant say I heard a huge difference...it did seem to make the amp feel slightly less stiff....maybe even "brown"

[SILVERGUN]

All I can say is WOW!!!!

Talk about bringing an amp to life!!!!......so this is what you guys do in your spare time
I am having more fun in the last 2 hours than I have had in the last 2 years.....some changes bring monumentus leaps in improvement while others are subtle, BUT, it's all coming together....
Once I got past being afraid to mess up my beautiful board, I have found the secret to the tube universe....this thing RIPS

I'll be back with the results, I'm keeping great notes, but I could do this for days....only problem is my ears can't take anymore, so I'm gonna take a minute and wire the master in, which will probably bring about another wave of changes.......

If you see my wife---tell her I love her..................this could be awile

[tubenit]

All I can say is WOW!!!!

Cool, sounds like you got it into the "WOW"  zone!

I have found the secret to the tube universe....this thing RIPS

Man, your enthusiasm is remarkably fantastic!  Congrats!  You got me chuckling pretty good with the "secret to the tube universe" line.

 

If you see my wife---tell her I love her..................this could be awile

 

Looking forward to the review and notes.   With respect, Tubenit

[SILVERGUN]

And then the master volume crashed the party......0 out of a possible 10....really bad ....it figures, because it was the only thing I added to the design......all of the magic is gone unless you turn it all the way up, which obviously defeats the purpose, and even then it sucks tone and sounds like crap.....boy, tonight is an eye opener.....guess what I'll be doin for the next half hour??....it's coming out!!!

T, everything I tried before this was WIN, WIN, WIN, WIN....I'm not gonna let it get me down......not every idea is a good idea...that's one of my favorite sayings

[tubenit]

I have the PPIMV on the D'Mars OD Special and like it alot.  I think it maintains a good tone down to about "4".

Glad some of the other mods to try were useful.

With respect, Tubenit

[SILVERGUN]

Guys, let me start by thanking Tubenit AGAIN for your his help....without your timely posts, "suggestive reasoning" and true directing skills, I would not have had the confidence to try everything that was on my list last night.....I had a "breakthrough"  experience, and it helped me accomplish something that I had wanted to do for years, and that alone is priceless.....THANK YOU!
You other guys know who you are and I really appreciate all of your input.....the fact that you guys take the time to help people you've never met still surprises me and inspires me to do the same....THANK YOU!

-I started by attempting to record some sound clips which was a total failure, and I apologize, because you guys deserve to hear what we've accomplished here,,,I'll work on that
-The first big changes came as I started to experiment with the bypass caps on V1a+b...I first disconnected the 22uf on V2b and tried it like that:
reduced gain, less harsh sounding, reduced bass response, reduced cool feedback effect,,,didn't like it.
-I then inserted a 1uf in it's place, and got a significant mid boost that sounded much better than having no cap there, but brought back some harshness, and was still lacking the bass response I originally liked
-Then just to go to the extreme, I disconnected both bypass caps at the same time and BLAH!!.....flat, lifeless, but the ability to feedback was not totally gone, which led me to believe that not all the magic is in those stages (that was an important lesson, because I had assumed it was)
-So then I reversed the previous values and put the 22uf back on V1b while switching the 1uf over to V1a....now we're on to something (unfortunately I was limited to those 2 values in stock here so I stopped there)
-The results made me play guitar for about 10 minutes with a huge smile on my face....I saw the light!!!
-The front end harshness was no longer an issue...it felt like a "real" amp now..it had ok gain and nice punchy upper and lower mids that just rounded out the whole tone beautifully...the feedback was more controllable...it didn't feel like I was wrestling with feedback anymore
-Feeling like I was halfway home I decided to leave those 2 caps in those positions and move on to that 56K resistor going to ground before V2a that jojo had originally mentioned.....MAN, DID THAT EVER LIGHT THINGS UP!
-I inserted a 250K pot in there and dialed it in , and it was literally like having a dial-up-distortion control....I sat there for 5-10 minutes just trying to dial it in and of course wound up on the high side, settling down at 220K, where it just seemed RIGHT...I also went back and experimented with the bypass caps again, but the values I had originally settled on were the best.....right about now, my ears are telling me to cool it, so i took a break and tried the master vol. idea i had posted
-I wired it just as I had drawn it in the schem. and it couldn't have been any worse...horrible, waste of time, tone sucking, useless,  but a good lesson...let's leave it at that ,,,,it's gone now, never to return again
-I tried the PAB mod by disconnecting the wire from the mid pot to bass pot, and it didn't make much of a change, but it did make for some flabby/muddy bass, brought back some harshness, so I reconnected it and liked it better like that
- I then clipped a 100p cap parallel across the 500p treble cap, and it gave it a nice treble boost (I couldn't believe the change), but it wasn't the direction I wanted to go and it made me question if i want to reduce the value of the 500p that's there......next session
-Then I tried the enhance cap, and again, couldn't believe the difference that made....I clipped a 100p parallel accoss the 82K plate resistor in the PI and it made a very ODD change...it added an almost clanky/honky effect to the OD tone and when i turned the vol. down on the guitar it added an effect similar to the sound of the piezo pickup on my Parker.....hard too describe,,,but not useful in this instance

-Last but not least I tried my resistive load attenuator, and that also acted a TONE SUCKER,,,it did it's job but also took away a lot of nice top end and a lot of favorable feedback and speaker interaction...but it has done that with every amp I have tried it on, even though the author says it wouldn't...here's the plans for that attached:

That's it for now....back at it tonight with a different guitar....and another attempt at recording

[llama]

I say Bravo to you, and all the souls who help with this awesome endeavor.  I absolutely love this!

Great job.  Can't wait to hear it!

[cbass]

Glad it's more to your liking. I've tried a lot of different things with this type of  circuit and that schematic I posted is very close to what I found to sound the best out of all the things I tried.Its basically a komet concorde.