Harmonic Jerkulator oscillation noise?

[Gregory Kollins]

I built Escobedo's Harmonic Jerkulator, and I'm having a small issue. The circuit works, but at low gain levels (100k pot next to input) there is a very constant volume ringing tone, very close to an E note. At first I thought it was feedback (this is what it sounds like) but I muted my strings and it kept on. The guitar comes through over the ringing, but it does not stop when I play. Does anyone have any idea why this would happen?

Edit:
I used a .1 cap instead of the .05, as was shown on the home-wrecker site. I wouldn't think this would cause the problem, but then again, I have no idea what is, so I might try switching it out for a .047 cap.

Schematic:

[mac]

Try a cap, ceramic or poly > 0.1uf, across the 22uf from emiters to ground. If the 22uf has a high internal resistance it can not bypass the AC signal to ground and cause motorboating.
Also try a big cap, >22uf, across the power rails.

mac

[Gregory Kollins]

Thanks, I'll try it out and post.

[Gregory Kollins]

The cap on the power did the trick. Thanks for the help!