Miss Piggy -low guitar vol give strange noise

[brett]

Hi.  I have this strange thing happening when I'm using my Miss Piggy (a fuzzface with doubled-up base-emitter junctions).  

It makes a strange sound, a little like radio static, but only when the volume is between 0 and 1 (ie virtually all the way down).  It's not loud, like an oscillation, but it's definately there.  It's not low, like a ground hum, nor is it a constant "shoosh" like transistor noise.  Compared with the circuit noise when the fuzz control is at 10, I'd say it's a little louder.

Any ideas what might cause such a noise??

For reference, here's a layout of the Miss Piggy..  Besides this minor problem, it's a totally awesome fuzz.

[Elektrojänis]

It could be radio interference but it just did not tune into any channel.

A long time ago, I built a basic fuzzface using 2n3906 for the transistors. It worked quite nicely with the standard component values, at least what comes to biasing (at least what I can remember of the sound, no gating, it does not exixt anymore though). It had only one problem... Some radiostations sounded through it. The radiostations were very quiet though but when I turned my guitar volume or tone totally down the radio stations became a lot louder.

How about a small cap from input to ground or from base of Q1 to ground?

[brett]

Thanks.  I'd heard of the FF radio interference thing, but not that it can get louder as the volume approaches zero.  I'll put a small cap (100pf) from the base of Q1 to ground and see if that solves it.

Thanks again.