First Post - Project Question

[Mike6158]

T4 Input amp
C: 5.723 VDC
B: 1.526 VDC
E: 0.952 VDC

(...)

T1 Output
C: 4.055 VDC
B: 0.647 VDC
E: 0.0514 VDC

That's a little weird. With a 100R emitter resistor and 10k collector resistor for T4 it's unlikely that you would be getting 0.9V at it's emitter. In fact, those voltages look like perfectly reasonable measurements for T1 (and vice versa - the T1 measurements look like they belong to T4). Are you sure you didn't mislabel the measurements?

I just checked and that's exactly what I did (wrote them down wrong). The schematic reads left to right T4 - T3 - T2 - T1 and when the board is right side up the component order is the exact opposite. I noticed that yesterday when I was testing with the scope and sig gen so I installed the board upside down in the vice but it never clicked that I took the readings backwards the day before.

Corrected

T4 Input amp
C: 4.055 VDC
B: 0.647 VDC
E: 0.0514 VDC

T3 and T2 Clipping section
T3
C: 4.095 VDC
B: 0.644 VDC
E: 0.058 VDC

T2
C: 4.084 VDC
B: 0.64 VDC
E: 0.048 VDC

Wiper on the tone control: 1.772 VDC (this was correct)

T1 Output Amp
C: 5.723 VDC
B: 1.526 VDC
E: 0.952 VDC

[balkanizeyou]

So the voltages look reasonable for a big muff. You can try incresing R6 value to 15k to get a little bit more volume out of this and achieve a more central bias of the T1 stage, but I doubt it would make a big difference.
I haven't used it in years, but I remember my muff being pretty loud. Assuming the board is fine, maybe there's something wrong with your offboard wiring? Doesn't sound like it, but would be worth checking anyways.

[Mike6158]

Right now the off board wiring is much longer than it will be and basically just splayed out on the test bench like on octopus

Into a 60's vintage Gretsch tube amp it's got ok volume as long as I crank the pi volume to full output. Into solid state Marshall Mini Stack II head not so much unless I click in the over drive button. In fact, I can barely hear it.

I'll put it in an enclosure, shorten the wiring up, and see what happens. Right now, on average, the wiring for the pots and jacks is over a foot long. That can't be a good thing.

I appreciate your help 

[balkanizeyou]

do you experience a volume drop when engaging the effect? If yes, than I'd suspect that something may be wrong in here.
If not and your problem is that it's not much louder than the clean signal and doesn't drive your amp like crazy, then I think that's just the nature of the beast. If you want the volume but don't want to change the way it sounds, you can just add a simple booster between the muff and your amp. If you need more output from the board you have and don't want to add any additional circuitry, you can change the clipping diodes to diodes with a higher voltage drop like LEDs - although be warned, that it will greatly affect the sound and lower the distortion/compression.

[Mike6158]

do you experience a volume drop when engaging the effect? If yes, than I'd suspect that something may be wrong in here.
If not and your problem is that it's not much louder than the clean signal and doesn't drive your amp like crazy, then I think that's just the nature of the beast. If you want the volume but don't want to change the way it sounds, you can just add a simple booster between the muff and your amp. If you need more output from the board you have and don't want to add any additional circuitry, you can change the clipping diodes to diodes with a higher voltage drop like LEDs - although be warned, that it will greatly affect the sound and lower the distortion/compression.

I don't really know. The bypass switch is just a jumper right now and I was concentrating on testing the effect. But, all settings on the guitar the same- the effect volume is much, much lower when I play through it. Ie, I can plug the guitar into the same input jack on the amp and it sounds normal. Go thru the effect and the effect volume is much, much lower. Even on the scope, amplitude is lower. Which sounds to me like something is wrong now that I type that. I think I'll go back to the original schematic and make sure my schematic, especially components, matches the original.

[Mike6158]

I was starting to wonder if some of the low output problem is because of my guitar. I borrowed a friend of mines ProCoRat and MXR DynaComp to see how they compared. The guitar is an old Ibanez that I bought in 1989 or 1990. It's pretty beat up. The MXR Dyna Comp behaves like my Big Muff ∏ meaning the volume drops significantly when it's switched in. The ProCoRat is the other way around and the volume is higher thru it, depending on the settings of course, vs bypassing it. I guess that negates the guitar suspicions...