GE Fuzz Face with Small Bear matched set - unwanted gating

[drummer4gc]

Hey everyone,

I purchased a matched set of PNP germaniums from Small Bear for a Fuzz Face clone, but the sound I'm getting is really gated and not the smooth Fuzz Face tones I've heard from other pedals. I sent the following info back to Small Bear, because their customer service is always fantastic, but I figured I'd run it by the fine folks here too for some other perspectives.

Q1 is an OC76 and Q2 is an OC77. I've got them on a breadboard right now using the following resistor values. With no input, the voltages on the transistor pins are as follows:


Battery - 9.06

Q1 (OC76, hfe=80, L=178)
C - .69
B - .11
E - 0



Q2 (OC77, hfe=118, L=217)
C - 3.51
B - .68
E - .55

The resistors in the circuit (don't have a corresponding diagram, but it should be fairly obvious which resistor is which):
R3 - 27k
R4 - 680R
R5 - 10k
R6 - 120k


I tried lowering the R5 resistor from 10k to 8.2k which brought the Q2 C voltage up to 4.5. This was an improvement but it still sounds gated and not correct. Then I replaced everything with an appropriate trimpot dialed into the given values and tried to go at it from that angle, but there are too many combinations to make this a worthwhile attempt without a little guidance.

I know the fuzz face questions get sort of old, but I've searched and researched and read up plenty. I know that this is an art that requires more than "4.5v on the Q2 collector"....anyone have ideas?

Thank you,
Matt

[Kipper4]

Check this out. Hope it helps

http://www.diystompboxes.com/smfforum/index.php?topic=98002.0

[LucifersTrip]

If there aren't any errors in the build and the transistors are good (they look good by the numbers), then you shouldn't have to do much more than tweak the two collector resistors....but try not to alter either too far from the stock values.

If you haven't already, try Q2 C voltage in the 5V - 6V range.

[rousejeremy]

Are you sure you are using the right pinout?

[drummer4gc]

Ugh. My breadboard testing rig (jacks and hookup clips) has a 100k volume pot built in so I don't have to wire up a volume pot every time I test a circuit. Turns out the fuzz face sounds like crap with that value! Hooked up a 500k proper volume pot and it sounds like I expected it to.

Thanks for your help and suggestions!

Matt