EP/OCD combo by Mas Effects - Question about feedback/oscillation

[PangeaDestructor]

Before I pull this pain in the butt back out of the enclosure and post pics, I'm just wondering if there is anything in the schematic itself that would be the likely culprit here. Everything is working great on my most recent build of this, except for one thing - with the EP in front of the OCD, the pedal starts producing feedback when the boost and ocd gain knobs start both approaching noon or one goes higher. Like the signal is just getting too hot in there when the knobs get turned up.

Does anything stand out just based on the schematic, that could be causing this, and any value or component adjustments based on the schematic that might remedy the feedback when boosting into the ocd side?

 

[swyse]

It could be input wires too close to output wires/pcb as well, i'd try moving wires if you haven't yet. Nothing on the schematics stood out to me as something that would cause an issue.

 

[PangeaDestructor]

Ok, here's an interesting twist - if i turn down my guitar's tone knob, the frequency changes and when tone gets low enough the squeal goes away entirely. it's totally muffled sounding, but I've tried two guitars with HBs and single coils with the same effect.

There is no squealing without a guitar plugged in.