Here's a doozy; as soon as the machine is turned on, the -32 sound board produces this absolutely horrible high pitch sound that doesn't stop. I've reflowed input headers, recapped the board, and tried another 8ohm speaker. The volume and pitch pots do seem to work (in that they affect the sound being created).

I was going to check the TIP29C transistor... anything else I should check or look at?

Thank you for pointing me in the right direction. I noticed R22 was burned but tested in spec. Replaced that, checked everything else in that circuit just to make sure. R36 tests 83ohms which is kinda high (supposed to be 75ohm) but I left it because I don't have an on-hand replacement. Everything else was good.

R22 was the issue!