Fuzz Face Help

[SurfaceDweller]

New builder here. I've put together 2 PNP germanium fuzz faces, battery power only. They both work great, but one of them has a "quirk".

When the guitar's volume pot is at or near 0 (off), it's like some kind of noise generator turns on. It sounds like oscillating frequencies, so I'm guessing it's some kind of radio interference. I think changing the length of cable after the pedal changes the frequency of the noise. This only happens when the pedal is engaged.

My other fuzz face does not do this. Could this be an issue with the way the circuit is grounded? To be honest I was a bit confused about where all the ground leads go...

Thanks!

 

[PedalBuilder]

New builder here. I've put together 2 PNP germanium fuzz faces, battery power only. They both work great, but one of them has a "quirk".

When the guitar's volume pot is at or near 0 (off), it's like some kind of noise generator turns on. It sounds like oscillating frequencies, so I'm guessing it's some kind of radio interference. I think changing the length of cable after the pedal changes the frequency of the noise. This only happens when the pedal is engaged.

My other fuzz face does not do this. Could this be an issue with the way the circuit is grounded? To be honest I was a bit confused about where all the ground leads go...

Thanks!

You should post pictures. Otherwise we don’t have any way of helping you.

 

[SurfaceDweller]

You should post pictures. Otherwise we don’t have any way of helping you.

It's a bit of a spaghetti fiesta in there... I've included the diagram I used for the foot switch, and the one for the rest of the pedal.

 

[Coda]

I would ground everything to the jack, with no two ground points connected (star-grounding). Secondly, Fuzz Face circuits, mainly Si ones, can squeal/oscillate due to RI. Your Gi’s might have been a bit higher gain, perhaps. The issue is about as classic as the FF enclosure. The solution is a 33p/47p cap between the base and collector of Q2…

 

[SurfaceDweller]

I would ground everything to the jack, with no two ground points connected (star-grounding). Secondly, Fuzz Face circuits, mainly Si ones, can squeal/oscillate due to RI. Your Gi’s might have been a bit higher gain, perhaps. The issue is about as classic as the FF enclosure. The solution is a 33p/47p cap between the base and collector of Q2…

I see, thank you for the advice! I may give that capacitor trick a try.

I have noticed that the issue is most apparent when running my pedalboard after the fuzz. I've read that FF's can interact badly with other pedals, and this seems to be the case.

 

[jwin615]

I see, thank you for the advice! I may give that capacitor trick a try.

I have noticed that the issue is most apparent when running my pedalboard after the fuzz. I've read that FF's can interact badly with other pedals, and this seems to be the case.

That's more so an issue with pedals before it due to impedance mismatch.
Never had much issues running pedals after fuzzes aside from input levels.