Diode was indeed flipped in the schematic, thanks for the catch.
Corrected a typo...Congrats guys !... That's a superb team effort and great show of talent as I watched this thread unfold.
Now, sorry for the noob question here, but doesn't that GC92H Ge diode fall in the unobtanium bin ?
Is there a known replacement or an equivalent part that would be easy to get ?
So, PedalPCB layout Tone control as per Original cuts Treble clockwise from 12 O'clock & cuts Bass counter clockwise from 12 O'clock.Quite good, I think—it's a pretty saturated-sounding fuzz, but there's a nice raggedness to the high end that makes it seem a bit more articulate than a big muff or something else with similar topography. It's an excellent bass fuzz, even with the 10nF cap in there. I've not played an original supa fuzz but I've built a copy of that circuit and found it too bassy to be usable; this is a much better sounding pedal and sits really nicely between what you might expect from a medium-gain TB circuit and an actual big muff.
I agree that the Tone control makes more sense Reversed so Treble is Clockwise from 12 O'clockOK, so!
I built the circuit on vero with the following parts:
Q1: 2N3440 / hfe 110
Q2: BC549C / hfe 513
Q3: OC140 / hfe 85 / leak. 0.00mA
D2: 5.1V zener
Q3 collector biased to 2.6V
Outside of those component choices, the only sub was a B20K for the W20K.
I honestly can't tell any meaningful difference versus the original. Sounds great, overall volume is about the same as stock - unity at ~2 or 3:00, good amount of output past that point. Extremes of the tone control sound about the same, and I can find a spot near the middle that's about identical.
I used the dirtbox effects layout I linked earlier, so consider that verified (fyi, the tone control is wired in the reverse from the original in that layout, but that might also be more intuitive...).
I'm stoked - thanks again for all the help in this!