I built one of these on stripboard from the circuit in the schematics. 4 caps, 4 resistors and 2 transistors. Everyone who has heard it can't believe the sustain on this unit and the extreme fuzz available from such a small board. The sustain rivals my Big Muff Pi! I used 2n2 caps in place of the 2n and 47n in place of the 50n in the schematic as they were all I could get. All 4 resistors are 470k. I used a 470k pot in place of the 330k for the fuzz and a 100k in place of the 33k for the volume.
I tried the following transistors;
BC109C and 2N3904 too much gain at high settings with howling and buzzing
2N2222A poor sound
Un Numbered Motorola good fuzz and sustain but noisy
BC184C superb right up to full settings!
I have yet to try some BC108 and BC107 transistors but I didn't have time over the weekend!
I will measure them tonight. I tried some BC108s last night and they sound good initially but have a very strange decay sound to them. I tried a mix with one BC108 and a BC184C in both positions and the strange decay sound was still there both ways round. I also tried the mix positions with 2N2222A transistors and BC109cs but neither sounded as good. I had some BC107s but I can't find them.
The BC 184c transistors measured 545 and 555 on my DMM. The BC109cs were typically around 650. I found a couple of previously used BC107s which sound excellent but give less than unity gain across the board. I couldn't measure them as I had cropped the legs and they wouldn't reach the contacts in the DMM. I hope this helps,
Did you use a mix of BC108/109? Whenever I use a 108 I get a superb initial fuzz which decays to a 'farty' sound whatever the second transistor is. I have tried BC108, 108B etc and all have had the same effect. As I have said the BC107 sounded fantastic but the gain is less than unity so when I activate the circuit the volume drops even at full gain. I might build a second board and try it again, or try a slightlydifferent layout with some 'L' configuration transistors ie 'BCE' as I bought a mixed bag which has loads of this type some with very low hfe.
