Debugging A Fuzz Face...

[ddavis20341]

Hi all,

So I picked up a fuzz face clone from Big Knob Pedals a little while back, and absolutely love it. But as I was going to take the battery out of the pedal a couple of weeks ago (to finally be rid of it), I accidentally knocked the leads of the LED together, and maybe into the jacks as well, which caused the LED to flash on for a second. I immediately took the (live) battery out and let the pedal sit for a while before testing it. It still produced a fuzz sound, but the fuzz was definitely different than before (a lot more noise and more of a nasally, gated type of fuzz). I didn't have any extra LEDs on hand, so I continued to play on it for another week or so before new ones came in. I swapped the LED for a fresh one, but the pedal still doesn't sound like it did before (still a load more noise and not as smooth, volume and attack have to be up way higher for the same output level as lower settings before).

I don't really have any idea of how to go about troubleshooting this, what voltages everything should be, etc., other than just swapping the transistors. Any help would be really appreciated. I will post pics below.

[mattlee0037]

The indicator LED shouldn't have anything to do with the sound of the pedal as it isn't in the audio circuit. I can't read the transistor type (big metal cans) but you can google "_________ datasheet" to find the pinout (which leg is base, collector and emitter). Then Q2 should have a bias of about -4.5v or 4.5v at the collector if I recall correctly.

[ddavis20341]

Great, I figured the LED wouldn't have affected it at all, but I wasn't sure if any other components were somehow damaged in the process. The transistors are an MP39B and an MP20B (the silicon is a 2N3094), so I will check out the voltages and go from there.