HT8950 (DBA Robot) oscilating/whining?

[commathe]

Has anyone else here had issues with this or know what might cause it? I have built it off the attached schematic:


However, on my breadboard all I get is a whine that vaguely interacts with the guitar but completely overpowers it. It does a bunch of weird things like stops making sound when I play certain notes on the guitar and then starting up again when I play certain other. I can't figure out what is causing it though. Would it be possible that stray breadboard capacitance is allowing it to oscilate by sending the output back to the input? The two pins are quite close. I've tried using small caps to filter the power rails but that had no effect.

[garcho]

I've breadboarded the HT8950 many times, with a few different inputs and outputs, never with any problems. Take some voltages and double check all the wiring and pins.

[commathe]

Will do. I already tried a second chip to check if the first one was bust or something. Looks like I'm going to end up stripping everything off the board and starting from scratch and being extra vigilant. I feel like I double and triple checked everything already but it's definitely pointing towards me having done something wrong.

[garcho]

Sometimes starting over from scratch ends up being the most efficient way.