Webster TP45 conversion

[ElusiveMoose22]

Hello All!  I'm new to the forum and also mostly new to amp building.  I'm looking for some input/help on the following from all members experienced in converting old PA tube amps into guitar amps. Any help given would be much appreciated!

I have a Webster TP45, 30 watt tube PA that I've restored to original working condition + adding a grounded power supply, a guitar jack input in channel 1 and an output jack and the speaker send for ease of running into guitar cabs.  She fires up on all tubes, has all channels working, and sends out a LOUD, clean, and clear signal to the speakers.  I've attached a schematic with the signal path of the mic 1 input highlighted.  It's really a very good and clean PA design.  Now to mess it up and make it a good guitar amp design lol  .

Running the guitar into the amp as is works okay, but it leaves a bit to be desired as a guitar amp.  It's very full frequency, but still kind of on the sterile sounding side. Also you couldn't make this amp overdrive with a guitar signal no matter how hot the pickups are.  Of course as a PA it was designed to defeat distortion and remain clean to top volume  .  On the plus side, this sucker is the loudest 30 watts I've ever heard in my life.  I'm a gigging musician and not squeamish about volume, but going into a 1 x 12 open back cab, I can't stand much past 3/10 on the volume before it starts to get unbearably loud.  I'm pretty sure the very low resistance on the negative feedback line helps contribute to the super loud volume.

I've also attached a scan of the modifications I'm proposing to make this better for guitar.  I could sure use some help/guidance on these changes to see if I'm on the right track or if anyone sees something off in my changes or knows a better way to do this.  I'm hoping to achieve the following:

1.  I'd like to keep the basic design in place, but change the values of the caps and resistors for mic 1 channel to be better suited for guitar.  I'd also like to do some similar light modification to the output section to make it more prone to breakup when driven. 

2. All three input channels share a 750ohm/200uf cathode.  I'd like to separate channel one from this so I can voice it better for guitar, but leave the other 2 inputs as is for now.  Can this be done by placing the 2.2k resistor and 22uf cap where I've added them?

3. Adding 68k grid stopper and changing the other resistor to 1m makes this first gain stage look a bit closer the old 1960 Vox AC30 ef86 normal channel schematic.  I think this is a good place to start no?

4. Adding 1k grid stoppers and 470k screen resisters at the 6L6 power tubes to get the power section to break up a little sooner.

5. Increase resistance on the negative feedback line to help the amp overdrive sooner, and also maybe slightly decrease the overall volume.

6. What did I miss, anyone see some other obvious changes they would make that I'm not addressing here?  I think the rest of the circuit is good for guitar:  2 EF86 gain stages, a James TS sandwiched between 2 triode gain stages, into a cathodyne phase inverter, into the 6L6GC power tubes... it's a bid of a long chain for a guitar amp but we should be all good here right?

Thanks again in advance for any responses! 

[sluckey]

Don't put 470K resistors on the 6L6 screen grids. Here's a little something that will be easy to do and give you an idea if you like the Vox sound. Also easy to undo if you don't like it. Just disconnect the left side of that .047 cap that feeds into the PI. You may want to disconnect those Zener clamp diodes too. Now rewire your Mic 1 preamp to look like this Vox preamp and connect to the dangling end of that .047. This should give you plenty of signal to drive your power amp.

[ElusiveMoose22]

Thanks sluckey! Mind explaining why no on the 470k screen resisters?  Just curious as to where I went wrong there so I can learn and understand for future projects.

I had considered an idea like that. I don’t know how Voxy it would sound with the 6L6’s in the power section, but it could be interesting lol. I’m not specifically going for Vox over any other sound, I was just already aware of their early pentode circuit and thought there was similarities here.  I’ve also seen a few Dr. Z schematics with EF86’s in the preamp section. Is suppose the same could be done tying any version of those to PI in the same place. My only dislike on this is tone control situation. About the only thing that I can figure to be done is placing a cut pot between the PI and power tubes ala Vox style.  But I’m not a big fan of just the cut control, I prefer have a way to shape the midrange a little more. I’m happy with the existing James tone stack, but it needs those other tubes to drive the signal through it into the PI. I don’t think that just the single pentode stage will give enough signal to pass through the volume and then tone stack without being boosted along the way, right?

[sluckey]

470K is extremely high. 6L6s would be happier with 470Ω or 1K. I suggested the vox preamp just because you had so many EF86s in there already. It would be very easy to try. The cut control will not work with a cathodyne PI. That's something I just recently learned.

All you need to drive that power amp is one tube. The EF86 is simple and easy. But you could do a Fender/Marshall preamp with a 12AX7 and put a TMB tonestack between the two triodes. Or do an Ampeg preamp with a 12AX7 and a James tonestack. These are just suggestions based on my familiarization with these circuits.You have a lot of options. Should be a nice amp.
 

[DummyLoad]

see attached - that's what i'd do. keep most of the topo - ditch MIC1 and MIC2 EF86 and cut the summing R's out + phono convert phono pot to Master Vol with the wiper feeding V4 pin2. clip the zeners out + 470K grid leak. change 750R to 2.2K and clip the wires to the other unused EF86 cathodes. it will have A LOT of gain - maybe too much.

if it has too much gain, then add an input jack to V2 for a low input.


--pete

[ElusiveMoose22]

Okay sluckey and DummyLoad, thanks again, I appreciate the input!  So taking what both of you told me, here's what I think I want to try now (updated schematic attached).

1.  I like disconnecting the phono line and using the phono volume pot to be a master volume before the PI.

2.  I'm also worried about there being too much gain after disconnecting 2/3 mic channels and the phono.  If I'm understanding it correctly, in the original circuit each channel has a 1m resistor just after the volume pots, phono included.  Then in the mixing channel there's a 1m resister from grid to ground making parallel resistance between all channels.  Isn't this helping attenuate the signal a good bit?  I understand these pentodes have a lot of gain, so by removing 2 mic channels and the phono I'd be increasing the gain from the left over mic channel by like 75%?  What about leaving the other mic channels intact and seeing how that sounds?  I'm not necessarily looking for a high gain monster, but I do want the amp to overdrive when pushed.  Also I like the idea of being able to use those channels re-voiced for a different instrument or input in the future.

3. I see where I got off on my values for the grid stopper and screen resisters at the power tubes.  I had been looking at EL84 schematics in other amps, but EL84's are true pentodes and need the higher screen resistance.  I got the new values from looking at multiple Fender blackface circuits with 6L6's, like the bandmasters and bassmans of the early 1960's.  These new values should work okay to help earlier breakup in the power section right?

[sluckey]

Looks like a good plan.

[DummyLoad]

if you're going to leave all 3 of the EF86 input pentodes in place - i wouldn't use a 2.2K to bias all 3 - leave the 750R in place  with the 750R that's like having a 2.2k (close enough) under each EF86.

suggestion: lose one EF86 use a 1.2K cathode R for the remaining two and strap one pentode as a triode, that's the "clean" channel - bond the inputs together or use a toggle switch to select either input or both - see sluckey's amp scrapbook for the proper switch & schema on how to do that.

personally, i'd split the cathodes and tune to taste with appropriate bypass cap for each pentode.

--pete

[ElusiveMoose22]

Thanks Pete, good catch on the shared cathode resister value!  I may move closer to the direction you’re suggesting. I want to try it out to see how it sounds with all three channels before I remove any from the circuit. Hopefully I’ll have time to work on it this weekend and see where I’m at after these changes.

[ElusiveMoose22]

For everyone who has contributed or is following along, the latest update is that I got my start working on making the amp changes Sunday.  I was able to finish soldering in resistors and two guitar jacks at the input stage.  I also removed the phono line and located the point I need to insert the old phono volume pot to make it a master volume.  Then I located the insertion point for the 1.5k grid stoppers and 470 ohm screen resistors in the power section.  That one will take some tricky rewiring and soldering to fit everything in there correctly.  There are a lot of tight spots in the exhisting point to point soldering, so it's a bit tricky and slower going than I'd like.  I'll be working on it again next weekend and hope to finish it up.  With a little luck I'll be able to post a vid of the results in the next week or 2 for anyone interested in how it turns out.  Thanks again all!

[sluckey]

A popular method to install 470Ω/3W screen resistors is to mount them directly on the 6L6 sockets between pin 4 and 6. And the 1.5K stoppers can mount between pins 1 and 5. Of course this assumes your PTP layout is not already using pins 1 and 6. Here's a pic...

     http://sluckeyamps.com/6v6plexi/P-6V6_05_big.jpg

This is the method Fender used.

[ElusiveMoose22]

Sluckey, thanks for the tip, unfortunately though pins 1 and 6 are already in use. Hence the slow going. No worries though, it will just take me some time to carefully rework things to fit my new resisters in the correct order within the tight quarters provided. Slow and steady, but done correctly like anything that’s worth doing lol.

[sluckey]

pins 1 and 6 are already in use.

Yes, back in the true PTP days the layout people were very good at grabbing unused tube pins and using them as tie points.

Could you post some pics of this amp?

[ElusiveMoose22]

sluckey,
Here’s two pics from when I first got the amp, before I’d done any modification or replaced any caps and added a 3 prong power cable.  I’m afraid if you want any pics of its current state, or close-ups of a specific section, it will have to wait until this weekend. The amp is currently at a garage I keep projects at, but I only drive out to it on weekends. If you do want to see something specific though just let me know and I’ll be happy to snap a pic and post it this Sunday. Thanks again for your continued input and interest!

[ElusiveMoose22]

Alright, managed to get some real work done this past weekend and finally have some results to post! Attached is an updated schematic showing all the changes to the circuit that I have completed. Also here are links to 2 short videos of me testing the amp in its current state with some single coils and humbuckers. I'm pretty happy with the results so far.   

The next order of business I believe is to make some adjustments to the Tone Stack. I'm happy keeping the basics of the current TS circuit in place, it is essentially a passive James/Baxandall TS, but the values of the capacitors around the tone pots are not ideal for guitar signal. I managed to get some decent tone out of the current set up, but required some very extreme settings between the bass and treble pots to do so. The bass is overwhelming everything unless I cut it out almost entirely.

Can anyone suggest some new capacitor values to start with that would allow the tone controls to make less high-fi frequency adjustments and more focused adjustment to the 60hz - 10khz range? FYI, the bass and trebble pots are both 2M, this seems very high for tone control, should I change those out as well?
Attached Files

[shooter]

I'm thinking out loud 
put a 2meg in parallel with the pot, poor mans 1meg
the TS recovery tube has a common Rk & cap, is that 50uF, or 50 volts?
if I was bored I'd give each half it's own R, and play around with cap values on the 1st half, I like 2.2uF as a start.
you're on your own with the TS, I've downsized to a 1 knob, maybe, and leave TS stuff on the guitar, or "built in", no user adjustable parts   

[shooter]

you're schematic hurt my brain, still in-progress

EDIT: TS change, cleaned up some, please verify

[ElusiveMoose22]

I'm thinking out loud 
put a 2meg in parallel with the pot, poor mans 1meg
the TS recovery tube has a common Rk & cap, is that 50uF, or 50 volts?
if I was bored I'd give each half it's own R, and play around with cap values on the 1st half, I like 2.2uF as a start.
you're on your own with the TS, I've downsized to a 1 knob, maybe, and leave TS stuff on the guitar, or "built in", no user adjustable parts 

Shooter,
Thank you for the input!  I'll have to look again inside the chassis but I believe the cap in question is a 50uf.  I know I definitely need to change the cap values just before and after the treble pot, as they stand now the treble sweep doesn't seem to effect anything lower than 1.4k.  It's my understanding that raising both cap values around the treble pot will move the range of the treble sweep down to lower frequencies more effective for guitar.  And I believe the inverse is true for the caps around the bass pot?  Meaning if I lower those cap values it will move the effective range of the bass sweep up into higher frequencies?

I'd like to keep the dual bass/treble control configuration since those two pots exist already, my only concern is being able to achieve something closer to a traditional guitar amp sound, having at least a bit of a mid scoop.  I'm also playing with the idea of modifying the TS to be like an old Fender Deluxe Reverb with treble and bass pots and a fixed value for the mids, but I may try just playing with the cap values in the existing circuit first to see what can be achieved without major changes.

[ElusiveMoose22]

you're schematic hurt my brain, still in-progress

   Yeah this is my first amp conversion and as I've been learning on the go I've come to realize that I did not choose an easy one to start with.  Needless to say my brain has been fried a few times in this process lol!

You're mockup does look very close thank you!  Looks like you're missing the .001uf cap after the treble pot though.  I think everything else is pretty accurate.  Thank you for taking that on, I tried to make a mock up of the entire circuit on LTSpice but that program is not as intuitive as I'd hoped it would be and I'm pretty much lost  .  All you help and input is much appreciated!

[shooter]

I did a little more and updated the schematic.

besides the TS you have a lot of "built in" tone circuits.  when I get to a convenient place i'll color up what I see.  The one that stands out is a .001 5.1k on the PI grid.
I used something similar, but I think it was for taming Highs.

Is your bass "bad, like muddy, muffled, or just too much, or is it more not enough treble?

[ElusiveMoose22]

Is your bass "bad, like muddy, muffled, or just too much, or is it more not enough treble?

It's just too much bass, very clear but too much.  Everything is probably still a little too full frequency as the original design was for high-fi amplification.  I think I may change the .02uf cap just after the recovery tube and before the treble pot.  I think if I drop that value much lower to .001uf or so it should shave off a lot of the bass signal that's lower than 100hz or so, correct?  Or is there a better place to do this? 

Also any idea as to what the purpose is for the 100pf cap and 360k resistor in parallel just before the bass pot?  I'm assuming they are trying to narrow or tame the signal a bit there as well?

[shooter]

added more schematic

100pf cap and 360k

I believe it's a parallel band pass? filter
google up series and parallel RC filters, and find your calculator 

aside;
my last build I stole some of the filters Bogner used in the Estacy, then I got with a guitar guy and "tweaked".  Those helped get my TS to a 2 position pot, left of center, right of center 

[DummyLoad]

from shooters' draft. value suggestions. start with the coupling caps, then tune the TS for the x-over points.

--pete

[shooter]

Thanks Pete, I'm more a "have gator clip will tune" kinda guy 
I finished the re-draw, added the .sch for your editing pleasure

[ElusiveMoose22]

Shooter & Pete,
Thanks again for the input guys!  Upon further research and playing around with simulations of other James/Baxandall tone stacks it seems there's no way I'm going to get enough of a mid scoop to arrive at a tone I'm used to.  I think the best way forward is to redo the TS circuit in the old Fender Deluxe Reverb style.  Treble and Bass pots with a fixed Mid value. 

Any reasons this might not work?  I understand this will load the signal down more than a James TS but I think I have sufficient gain stages to recover and boost the signal back up again before the output tubes.  Any ideas where the new TS should go?  I'm thinking between the 2nd EF86 and the 1st 6CG7 triode? 

[shooter]

Any reasons this might not work?

should work, but you commented like to keep close to original design (paraphrased n to lazy to look:)
If you haven't switched, "dialing" in tone is more artistic than brute force.  Take each stage, tweak it and take notes, move right, repeat, or not 

[ElusiveMoose22]

Any reasons this might not work?

should work, but you commented like to keep close to original design (paraphrased n to lazy to look:)
If you haven't switched, "dialing" in tone is more artistic than brute force.  Take each stage, tweak it and take notes, move right, repeat, or not 

Fair enough point haha  . I did finally manage a mock up in LTSpice though and I haven’t been able to find a combo of cap changes yet that is capable of dialing in the frequencies I’d like to be hitting. I think the mid scooping limits of the James TS is where my problem lies. Therfore the best way forward is to change to something that lends itself better to that purpose. Running the changes in LTSpice does give the benifit of seeing the changes before doing all the work, so I will keep tinkering there before making physical changes to the circuit. We’ll see what happens *fingers crossed* lol

[shooter]

I did finally manage a mock up in LTSpice

I gator clip a cap in parallel with a cap in the signal path that "looks cool", and ask the player; "better / worse" 

[ElusiveMoose22]

Here's an updated schematic for the tone-stack changes I'm considering. Much thanks again to shooter for all his work drawing up the nifty simplified schematic!  It made it much easier to draw out these changes as the old schem was a bit crowded. 

After getting some help on another forum, I placed the Fender style TS between the first pair of triodes because the 6FQ7 tubes have a much lower output impedance than the pentodes I'm using in the first 2 gain stages.  The triodes should be much better for driving the heavy load of the Fender TS.

I also placed a voltage divider where the old bass control was to attenuate the signal coming from the pentode stages so all that preamp gain doesn't overdrive the triodes too hard.

Anyone see any potential issues, changes, or things I missed?  Thanks in advance for any input! 

[ElusiveMoose22]

One more update with 1 small change and 1 note:

Upon suggestion I upped the grid leak resister after the TS to 1M, and I made note of the shared cathode bias between the first 2 triodes.  If I find the cathode bypass cap needs to be adjusted to change the amp voicing it will effect both triodes in the tube, whereas separating and biasing the triodes individually will allow greater flexibility in fine tuning the frequencies I want to highlight in the amp voicing. 

I probably won't get to making the TS changes for another week or so, but I will post more vid results and updates for those that have been following once I get the work done 

[sluckey]

The shared cathodes absolutely need to be separated. As shown you have a positive feedback path between the two triodes and that sets the stage for a screamer.

[ElusiveMoose22]

The shared cathodes absolutely need to be separated. As shown you have a positive feedback path between the two triodes and that sets the stage for a screamer.

Interestingly I think the positive feedback path you're referring to has always been there, even in the original design right?  I'm looking at the original hand drawn schematic and shooter's printed schematic before the TS was changed and moved.  If I'm reading correctly we haven't changed anything except placing the entire TS where the treble used to stand alone and placing a voltage divider where the bass pot was before the first triode to simulate the attenuation that the bass pot previously provided to the signal before we moved it. The rest of the circuit remains intact as it was designed, shared cathode bias and all...   I've never had any positive feedback screams from this amp in my tests before and after modding it, and I've cranked it pretty loud.  
Or am I missing something here that you see? 

I'll probably separate the cathodes anyway as it will be easy enough to do.  It couldn't hurt to be on the safe side lol.  Just want to understand as I'm still learning here.  Thanks in advance for any explanation :-)

[shooter]

I've never had any positive feedback screams

It's not that it WILL, but it could.  there are a lot of early examples from the big guys that have shared parts, best practice separates them to avoid the possibility, and it does make stage tuning easier.  The same goes for PS taps,1 tube, 2 tube on same tap, ok, add a 3rd stage and you're asking for trouble

[ElusiveMoose22]

It's not that it WILL, but it could... 
...best practice separates them to avoid the possibility, and it does make stage tuning easier.

Makes sense and seems like sound advice to me, thanks!

[PRR]

> the positive feedback path you're referring to has always been there, even in the original design

Yes. But it is a low-gain tube, significant loss in the tone network, and loss across the cathode network. *In the original* it was marginally stable. If you are going to hack the tone networks, spend the 62 cents for separate cathode networks.

[ElusiveMoose22]

So I was able to do some work on the amp on Sunday, but did not finish as much as wanted. I have all of the old TS circuitry out and I got the capacitor and 2 resisters in where the old bass control was. Next weekend I will still have to wire in the new TS and separate the cathodes of the dual triode that are tied together. Hopefully I will be able to get all that done and have another update and video of how it sounds.

In other related news I discovered something interesting while working on these updates Sunday. At the first 6FQ7 dual triode in the signal chain, where I'm making all these changes, the triodes were originally wired in backwards. Meaning where the schematic shows connections at pins 1, 2 & 3 in the amp those connections are actually at pins 6, 7 & 8. And the reverse was true, where the schematic shows connections to pins 6, 7 &8, in the amp those connections are actually at pins 1, 2 & 3. It's definitely the original soldering and wiring connections so this happened when the amp was manufactured in the 1960's. I know it doesn't matter to the amps functionality which triode is wired in first as long as the anodes, cathodes and grids are connected to the correct circuitry components, but I couldn't believe this made it past the original inspection lol. Anyone else ever run into something like this or is it actually a regular occurrence and I just haven't happened across a switch up like this before?

[sluckey]

Or another possibility... The schematic is wrong.

[ElusiveMoose22]

Or another possibility... The schematic is wrong.

Certainly possible!  Though if I remember correctly I think the original hand drawn schematic I posted was a photocopy of one somebody found inside an instruction manual banded to another unit somewhere.  Could be one somebody else drew in there and not a manufacturers schematic though.    Took me a good 45mins to figure out what the heck was going on though before I realized what was up. 

[shooter]

update 2.1
let me know if mid should be adjustable

I went ahead and split yur cathode and penciled in suggested values 

EDIT:  cleaned up schematic

[ElusiveMoose22]

update 2.1
let me know if mid should be adjustable

I went ahead and split yur cathode and penciled in suggested values 

Thanks for the update shooter!  Mids are fixed 
those are actually 2 of the cap values I'd already picked to try out, one for each side haha!  I'm going to try no bypass caps first and then add one to the first triode for comparisons sake.  Then I'll try one at the first and second triode together if needed and change the values around to see what works best.

[ElusiveMoose22]

After working several hours Sunday and then finally clearing some space at home to bring the amp back and do some final tinkering on Monday I am pleased to announce that the mod to Fender AB763 style tone-stack is a success!  I'm much happier with the sound I'm getting out of it now, the Midrange and Bass frequencies are much more under control. Here's a low gain test with single coils:

And here is a higher gain test with a bridge humbucker:

Please take into account that these vids were from a spare room at home this morning so I was only able to test at bedroom volume levels. I don't really have the output section of the amp working too hard at these volumes so all the gain and compression you're hearing is coming from the preamp. As a result the higher gain is a little fizzy sounding in the second vid.

When I'm able to open the master volume all the way I can get fully clean output plenty loud enough to gig with, or push it a little more and get an edge of breakup sound. But I can also dial the master volume back to 7-8 and push the preamp volume even more and get some medium to high gain sounds also at gigging volume. It's not quite cranked Marshal territory, but I'd say it's pretty close to a classic AC/30 going full tilt. Some real high end sizzle but still a fairly thick and chewy distortion. I'll try to post a vid of this next time I know my neighbors aren't home and I can get away with the volume lol 

At any rate I'm pretty happy with this overall design and the results I'm getting so far  . I will need to tinker with a few things here and there, but the amp is definitely at a usable stage right now. I'll need to play it a lot more, run pedals through it, and get it out for some gigs before I know what else might need tweaking, but I'd say it's probably 95%-98% there.

Tell me what you guys think, I'm curious to know other peoples thoughts 

[ElusiveMoose22]

Tried some pedal combinations this morning to see how the amp takes them.  Four pedals on in this vid and the amp still has plenty of headroom and dynamics stay in tact pretty well even with multiple effects running:

I'd say it takes almost all my pedals really well except for my tube screamer and klon style pedals.  Even after scooping and taming the midrage with the new tone-stack all my drive pedals with a pronounced mid hump sound just a little too honky.  They would still be usable in certain situations with single coils, but probably not usable at all with humbuckers.  I think it's the pentodes in the preamp just wanting to push frequencies around 500hz-800hz in front of everything else.  They grab that mid boost from a tube screamer or klone and run with it lol.  Still experimenting though so we'll see what other effect do and don't work well and if the amp can be tweaked to be friendlier with all of them.

[shooter]

don't know enough about pentode pre tubes, but my brain says circles 1 n 2 might be areas to tweak freq 
circle 3, you might be able to remove both R & C 

[ElusiveMoose22]

don't know enough about pentode pre tubes, but my brain says circles 1 n 2 might be areas to tweak freq 
circle 3, you might be able to remove both R & C 

Thanks shooter, I'm looking into those first resister and cap combos you circled and will see what I can learn.  On the third one I know it's there to pass high frequencies to ground.  I bypassed that once to see what it sounded like and for guitar it didn't make much of a difference, but the amp was a little less stable when driven hard.  I decided to leave it in for now.

[sluckey]

Those first two circles wont affect tone. The resistor is just a B+ dropping resistor for the screen and the cap is a filter cap.

[shooter]

Thanks, I got the drop R, the cap however was "looking" like possibly a series RC circuit

[John]

Those first two circles wont affect tone. The resistor is just a B+ dropping resistor for the screen and the cap is a filter cap.

On the preamp tubes, those act as bypass caps for the screen much like K caps do. By lowering value it boosts less bass freq. I've tried the "morph" control in Merlin's book, and decided I like it fully bypassed. For a PA system, I can see that they'd be more critical. All THAT said, I have more tone shaping success with the K caps on the small pentodes, just like any other preamp tube.

[ElusiveMoose22]

With regards and thanks to shooter for his help with the previous schematic drawings, I went back and did a final schematic myself of how the amp currently sits.  I'm very happy with all the modifications I've made.  There are still 2 inputs and the 2 corresponding pentodes in the preamp.  I plan to leave Input #3 in place as a microphone input, but I will go back eventually and utilize the pentode from Input #2 to drive a tremolo circuit.  Not sure when I will get to it but I'll update the schematic one last time once I do.  Thanks again to everyone who helped along the way with this project 

[shooter]

to leave Input #3 in place as a microphone input

the architecture of the amp looks like it'll make  a crazy screaming harmonica amp 
Mr. Dillon look out 

[ElusiveMoose22]

the architecture of the amp looks like it'll make  a crazy screaming harmonica amp

My thoughts exactly!  Now if only I didn't suck at the harmonica lol