Ge Big Muff oscillation

[Greenhill]

Heya!

I made a fuzz kinda like the two first transistor stages of the Big Muff, using old PNP ge-transistors - shorting Q2 emitter to ground for more gain. Before adding the diodes I tried it out. It oscillates and sounds like a old fishingboat idling - weird noises.

When I turn the sustain (trim pot) down it stops, but it doesn't distort anything then, even when I clip on the diodes.



Voltages:

Q1
C:4.51 B:0.17 E:0.08

Q2
C:5.06 B:0.24 E:0.00

Yes - it's positive ground.

Any ideas ?

[brett]

Hi
sounds like a grounding problem. The sustain pot runs to ground, right? (ie +ve)
Keep the 100 ohm resistor on the emitter of Q2 - it doesn't affect gain (unless you put a large value resistor in there).
cheers

[Greenhill]

Thx I'll check for grounding problems then - will report back

[Greenhill]

Note to self: remember what wire is ground and what is output.

Thx Brett