2:90/TriAxis badly misbehaving

Well, here's one that made me **** my pants:

Let me start off by saying that I keep my amp(s) in a controlled environment free from dust, moisture, extreme hot/cold and away from prying hands. It's literally just sitting there until it's rehearsal time.

The other day, my TriAxis sounded like it had gain maxed out and the clean channel was ear-splitting loud. It turned out the final "Output" pot suddenly had only two settings: 0 and max. Ran it into the PA board, same issue. Turned it off and borrowed my bandmate's ENGL E530 preamp.

So we hook the thing up to my 2:90, I play one song using the 2:90+E530 combination and out of nowhere, the 2:90 loses 80% of it's volume (on channel A). If I turned the volume up to max, it was like having the volume on 10 o'clock. Terrified, I turned the whole thing off and played the rest of rehearsal with my GT-6 going into the PA :roll:

Now comes the weird part: I take the amp home, hook it up, works normally. Gain level normal, 2:90 working fine, tubes glowing nicely, no odd behaviour after 1 hour of continuous playing. Everything check check check. Yay. My least favourite kind of problem. The one that comes and goes for no reason. :x

Does anyone have any idea what the living hell could've happened? Only thing I can think of is dodgy power supply.

Bad /intermittent cable , corrosion on plugs or jacks , on both guitar signal path and speaker cables or a problem with the switch track cables, Dirty Pots ? Good places to start.

+1 for dirty/aged pots

Thanks for your responses, guys.

I had tested all my cables and they checked out.

I jumped to the pot conclusion as well, but that wouldn't explain the 2:90 going silent. Is there a way to clean the pots without taking them out?

I went through the setup at the rehearsal space with the other guitarist and the only thing we could think of is the extension cord (regular white multi-socket extension) that I use might be dodgy. I'll prod around with my multimeter but I can't get to my amp right now since we only practice during weekends.

I have confirmed that it was a bad power supply. Eliminated the extra extension, plugged straight into the main extension, all fine. Also fine on two concerts. Verdict: no juice, no party :lol: