Red Llama Squeal

[skypn]

I have just bread boarded a Red Llama, and there is this piercing high squeal, kinda strobing, riding over what otherwise is a great sound. If I adjust the pots, it kinda goes away, but only if the knobs are in a "sweet spot". Ive checked my connections and values. And usual suspects?
TIA

[madbean]

It's a pretty high gain circuit so squeal on a breadboard is a possibility. But, you should not have any at lower gain settings.

[skypn]

Ok, I've just re-tested it, and the squeal is pretty much throughout the whole range of the pots, except a couple spots in the middle. I'm using a schematic other than the Snarkdoodle. I checked the Snarkdoodle's BOM. I've used all MLCCs, and no film caps. I did use the one 10uf electrolytic. Could that contribute to the problem? Should I go ahead and etch a pcb, to eliminate any bread board issues? 
TIA

[madbean]

MLCC can be microphonic so maybe. But the squeal going away only in the middle of the range is pretty bizzare. Possibly the issue is in the breadboard itself. Or maybe the pots need contact cleaner.

[skypn]

Thank you for the leads. I'll etch and see how that sounds. Also, I didn't trim *any* of the leads so I guess I do have a few antennas going on

[midwayfair]

Did you breadboard in all the power filtering? Ignore this if you're using a battery, though.

Just to clarify, this circuit has a LOT of gain, and almost anything creeping in can cause some issues. Ground your unused op amps, and put a resistor in series with your input voltage to make the filter caps work better. Keep your inputs and outputs separate.

[skypn]

Here is a schematic of the power

I also tried it with a battery, no change. There is a resistor at the input. I changed the mlcc to films.
This is how the op amps are being used

Pins 14 and 15 are connected to the gain, and 9 and 10 to the volume. All the pins marked in red are connected to 9v+, pin8 to GRD. All others are not connected.
Its sounds like I'm trying to tune in an old fashion radio when adjusting the volume in the middle. I tried another pot of the same value to no avail.
I hope I have given all the facts needed to help without over kill.
TIA 

[midwayfair]

Here is a schematic of the power

Put a resistor in series with the diode.

You can start with something as low as 100R, but I would actually just go with a 1K.

[skypn]

Put the resistor before or after the diode?

[skypn]

MUCH better. I put the resistor before the diode, then after, not any difference, but either way MUCH better than before. Thank You!