Ampeg V4B advice?

[hublocker]

I'm only getting minimum volume out of either channel on my V4B but when I play with the "Low boost" rocker switch suddenly all the volume is there.

Lots of crackles and pops with the volume controls too.

Should I take it in for service or get a spray bottle of DeOxit?

The amp hasn't been on the bench or really used much for about 25 years.

[Alex1984]

Tech time, even if there's no problem, it'd be great to get that head up to spec.

[beatsbears]

Probably needs new caps at least, bad power to your tubes can seriously cut your volume and tone.

Maybe other things as well, your tech should know what to do.

[johnk_10]

IMO, it has nothing to do with tubes or caps and is more likely dirty contacts on your bass boost switch and pots.

[beatsbears]

Even if the caps aren't causing the problem, if it hasn't been used much or seen a tech in over 20 years you should probably still get them replaced, IMO. The older ones were only really rated to last a bit over 10 years and even if it hasn't been played much those older caps wear out just from age.

But johnk is probably right about the pots needing cleaned.

[Bassmec]

Originally Posted by beatsbears

Even if the caps aren't causing the problem, if it hasn't been used much or seen a tech in over 20 years you should probably still get them replaced, IMO. The older ones were only really rated to last a bit over 10 years and even if it hasn't been played much those older caps wear out just from age.

But johnk is probably right about the pots needing cleaned.

Great Amp deserves properly looking after.

[derridiandrift]

Originally Posted by johnk_10

IMO, it has nothing to do with tubes or caps and is more likely dirty contacts on your bass boost switch and pots.

John's on the money here.

The amp might need caps if it's been sitting for a very long time, but that would be a completely different problem from what you're describing with the rocker switch.

[SwansonEricJohn]

Yeah, sometimes my old(er) amps need the switches moved back and forth a few times and the pots turned. My V4 switches have this "netherworld" where there is sometimes no sound. I think the contacts are dirty.