Thomas Vox - germanium transistors and heat?

[MWaldorf]

I've got a Thomas Vox V1031 that's stock and in very nice condition, with one exception - after it's been on a while, there's an unpleasant distortion at higher volumes. Shutting off the amp and letting it sit solves the problem. Could this be an issue of the germanium power transistors getting hot? Before I take the amp apart and messing with things, I'm thinking it might be time to install silicon transistors (and adjust bias accordingly)

Thanks, Mel

[Mick Bailey]

Even if you decide to swap out the Ge transistors, you should first determine what's wrong. If it isn't the transistors you could complicate further diagnosis by introducing changes. A can of freeze spray should pinpoint any thermal issue.