Vox AC30 TB (2002 Model) Squeals when switched from standby to fully on

[imsilly]

I just purchased a vox, it had been stored away for 5 years and had never been played other then to test it worked. After about 1 hours play the amp suddenly starts emitting a loud hiss/squeal, so I quickly flipped it to standby. After a few minutes I switched it back on, no hiss/squeal but the volume was extremely low.

This pattern keeps repeating itself. Is there something I can do to fix it or will it need to go to a shop? Preamp valves was my first guess, its still got the same valves as when it was manufactured, or could it be something else?

[Garydean]

Have you tried swapping the first preamp tubes or output tubes? They usually don't go bad if they sit for 5 years but maybe the amp was jarred or bumped at one point. Had it been in the cold just prior to turning it on? I would look at tubes first.

[Robert M. Martinelli]

Your problem seems to rise after a while, so it could be related to a thermal drift of some sort....so....

+1 for a possible "bump/fall" or a mechanical shock of some sort in the past. Check for bad/oxidized/cracked solder joints or contacts.

Another thing I would not overlook is the tube sockets, if the amp's been stored away for a long time ( with temperature and humidity changes ) chances are the sockets could be oxidized, and this can give strange symptoms like the ones you're experiencing.

Hope this helps

Best regards

Bob