Fuzz Phase

thepedalarchitect · Post by **thepedalarchitect** » 25 Apr 2023, 20:20

Hi guys,

it's me again. Does anybody of you build the Fuzz Phase pedal:

https://pcbguitarmania.com/wp-content/u ... g-Docs.pdf

I was wandering if there are Ge-Transistors (T1 - T8) in addition to Q1-Q4. There are no further informations in the instructions but the circuit and pcb says you will need 8 soviet Ge-trannies (7x MP37, 1x MP42).

Do I need specific hFE for this build so I have to select them?

Maybe sobody can help me because he / she already build this pedal.

thepedalarchitect · Post by **thepedalarchitect** » 06 May 2023, 07:18

Does anybody build this pedal and could help me out with the transistors?

mauman · Post by **mauman** » 12 May 2023, 21:29

I haven't built this, but MP-37 are low-gain Russian NPN germaniums, and MP-42 is PNP. Typical beta/hfe seems to be 15 to 30, see this thread: viewtopic.php?t=25749

thepedalarchitect · Post by **thepedalarchitect** » 19 May 2023, 17:29

Yeah. I know the values of these transistors but they aren't on the parts list and instructions but on the circuit and PCB.
That's why I was a bit confused. I will use some transistor sockets and will try out MP37 and MP42.

mauman · Post by **mauman** » 19 May 2023, 20:30

Not to knock PCBguitarmania, but this is supposed to be their support forum and they're absent.... I did join their FB group to see if they're alive, and they do seem to be active over there, if you have more questions. There's no updated schematic for this PCB that lists those Ge transistors in the BOM, though.