Peavey triple xxx changing channels on its own???

[Danglin' Fury]

Sooo.... I have a Peavey Triple XXX on the bench and, at rest, it is cool. Put it in Crunch or Ultra mode and start playing... and the amp changes between Crunch and Ultra whenever it wants to. The guy that owns it has no footswitch so it does it without one plugged in. Any ideas? It doesn't switch in clean mode and it only switches when you start playing. Weird.

[Enzo]

Try various panel switch settings, and bang on the top with your fist. Does the amp switch when you bang it?

MY first suspects are the footswitch jack on the rear, and the circuit board it is on, plus the ribbons to the main board - if that model has them. Look close at the jack and resolder it.


That switching is simple relays, but there is also a transistor at the FS jack to complete the switching circuit when no FS is in use. If the resustir that holds its base up or the transistor itself is flaky, this could result.