Amp repair help….

[Mikeyboyeee]

I’ve got the V2, and you have to manually change the cord to the preferred amp’s input, and it does have that issue. It’s a great unit.

When I plug into each amps input, no issues. When I go thru the amp to switch inputs, I have a problem.

 

[glpg80]

Update! I finally got around to troubleshooting and with no preamp tubes installed, there is now air raid siren. The only time it happens is when I put a tube in V2. Tried many different tubes, with no avail. Suggestions? Thanks fellas!

Air raid siren? Does it change pitch?

V2 and V3? With no V1? Do you know if stock the first stage is V2a or V1B? Marshall liked to switch between them for the first stage.