Ampeg VT120 Acting Funny

[harmonix]

Hi all, newb here.


I have had an Ampeg VT120 sitting around for 2 years and not sure what is really wrong w/ it, and don't want to dish out tons of cash for something that can mean just tube replacement, etc. I've read that these amps are awesome, but I just haven't heard the full potential of the am.


It comes on and has normal volume once it's on. After a while (seems once tubes warm up) the volume goes DOWN. If I turn up all the way, I can get okay room volume, but at times it goes back to full volume and LOUD.

Not sure what I would need to do, so I've been using it as a cab for a no name v-4 clone head.

Any suggestions, comments, and what not?

[bluesfreak]

Hi,

For detailed TS it would be required to measure heater and plate voltages to see if they brown out but usually such symptoms are caused by dirty/corroded input and/or FX send/return jacks. If present jumper the FX loop with a patch cable and check, also giving the input jack a good shower with DeOxit would be first action. All further TS would require to work on the powered amp open so it is a job for a qualified technician...

just my 2c
bluesfreak