Opamp Squeal

[Faber]

Hello all.  I've recently been working on a simple non inverting opamp distortion.  I have two problems.

1.  There's this really bad high pitched squeal whenever I'm not playing.  Input/Output caps are 1uF each and the cap in the feedback circuit (to ground) is 0.1uF.
2.  When I try to soft clip, it kills the signal and it starts breaking up like mad.  I've tried Si and LED (maybe Ge?).

Other info:  I have the gain set at 1001 (maybe too high?) and the large caps are because I'm trying to make a dark, bassy distortion.

[Brian Marshall]

cap values don't mean much without knowing what is going on around them.

the squeal might be due to layout.  If you have a ridiculous input impedance like 10M or something that could do it too.  Try putting a small capacitor in the feedback loop of the opamp.

[Paul Perry (Frostwave)]

That gain is asking for trouble, or at least asking for critical layout.
Physically large caps don't help either.
I imagine when it clips, combined with the high gain, the bias goes off & the whole thing goes to hell.

[Faber]

Well, according to what I know from the AMZ Impedance article, the input impedance is 2.2M (from the resistor biasing the opamp... there's a fix!).
I'll tone the gain down, use both the opamps, and do the small cap thing.

Thanks!!!

[Faber]

I did the small cap thing and tuned the gain down to 101.  It's a lot better now.

Thanks again!