I'm doing a simple fuzz build completely from salvaged parts but I didn't have that much material to begin with so the diversity of my transistor options is quite poor.
How freely can one replace transistors suggested in the directions with other transistors of same type (npn/pnp). How will "wrong" transistors affect the function of the pedal? Would a fuzz turn into a boost pedal or would the finished pedal only fail to match the tone of the original pedal?


EDIT: I've got a pair of silicon BC238's and I'm supposed to use "NKT275 or other good germanium transistor of the PnP Configuration"

-will the silicon change nothing but the tone?
-are bc238's pnp or npn?
I'll just have to reverse the electrolyte capasitators and the bat if they're npn rite?
Last edited by taatelikoira at Nov 9, 2008,
Go here for some good info: http://www.datasheetarchive.com/
Has loads of info on not just transistors, but various IC's etc.
Even has a cross reference option so you can see what transistors can be substituted.
most transistors of the same type can be subsituted. same type means both polarity (pnp, npn) and well, type (mosfet, bjt, etc). all of them will differ even if they are the same type, but that shouldnt really change too much. other than tone and headroom of course.

the BC238 seems to be an npn transistor though, so you will have to change the polarity of the entire circuit. that means if something is at +9V it needs to be at -9V, and vice versa. and electrolytic caps and anything else with polarity will need to be reversed (except diodes). so basicly yes, battery and capacitors are the main things (and probably only in your circuit). could turn it into a boost or could just have different fuzz characteristics. its worth a shot if youve got no other use for these parts.