Fuzz face craziness when guitar volume is off and sometimes on

[AntKnee]

Let me first say that I've been reading up on this topic for a couple days now, and yes, it is a common problem for fuzz face circuits to hum and play the radio when the guitar volume is down. My problem may be a more extreme symptom of the same problem, but I'm bringing it up here anyway.

A friend asked me to look at his fuzz pedal because he said it recently started making lots of wild noise when he turned his guitar volume off. Knowing that this was common with some fuzz circuits, I said I would look at it.

A bit of history on the pedal itself... It was built in 1997, by a local Austin amp guru named John Bessent. This was long before most of us were building pedals and way before you could have the parts delivered to your door. It was built on perf and appears to have had a jack replaced along the way and some wear and tear. It's not the neatest build I've seen, and until recently it was functioning just fine.

After giving it a good look, I concluded it is a very basic fuzz face clone, and actually has fewer components than any of the
layouts I've seen online. Upon testing the pedal myself... Wow, this really makes some noise. It goes in to full on oscillation, pitch shifting synth like madness when the guitar is off. It makes different sounds depending on pickup selection. Once it starts making noise, you can manipulate the pitch and/or frequency with the fuzz knob. It sounds more like a Machete than a fuzz face.

So, can I tame this thing and if so, how? Have the transistors gone out of spec or something?

Here's a pic and parts list:
Caps: 22uF, 2.2uF, 10n, 4.7nF
Resistors: 330R, 33K, 100K, 8.2k
Transistors: C1815 (NPN)

[Bret608]

That actually sounds to me like one of the ground connections in the build has gone dodgy or intermittent. My Fuzz Face build did the same thing on my test rig when the ground wire in the rig was coming loose from the lug it was soldered to. Take a look at that purple wire that's laying across the tip of the output jack. Has it gotten worn over time from having a plug inserted and removed over and over?

I'm also wondering why the builder tacked that 4.7n ceramic cap across that resistor. An attempt to tame noise or something?

[AntKnee]

If anyone was curious how this resolved...
It turns out the enclosure lid was pressing down on the electrolytic on the edge of the board, which was causing it to make various kinds of crazy noise. It was kind of fun to play around with, honestly. I replaced it with a low profile capacitor and rearranged the guts a little to ease the pressure on the board and now it works fine.