In the polysix circuits, there are lots of .01uF, not .1uF. I'm not familiar yet enough with circuit theory to say wether or not those are the decoupling caps for the polysix. Can someone tell me?
My high pitch (and i call it pitch because it's audio range) noise that happens once in a while, is seeming likely to me to be a cap issue somewhere. I'm hesitant to start recapping things without having more of a target. Though i suppose it couldn't hurt to do the two big power ones and the five or six other small ones that are on the same power board.