Marshall AVT50 Pops when Switching Channels

[morta]

Folks, I have a Marshall AVT50 that makes a very LOUD popping noise when I switch between channels. I see a few other occasions of this issue on the net, but haven't seen any solution - probibly didn't look in he right places... Has anyone else experienced this issue and maybe has come accross a fix? Thanks, Al

[morta]

Folks, Two points of clarification on this...

1. The noise it makes is actually a dramatic, momentary, increase in volume vs. a "pop", and
2. This occurs both when switching the channel selector on the face of the Amp and also using the Footswitch


Thanks for any pointers you can offer..... Al

[gain-wire]

Well, the first thing that comes to mind is dirty relay contacts.

however if this amplifier uses JFETs to switch between channels, then it might just be a loose connection or component somewhere in the channel switching circuit. You'll have to take it apart and measure some voltages. And try to write to Marshall for a schematic, you'll need one.

cheers