Tube amp troubleshooting

[Spivonious]

So I'm at practice last week, and we've been playing for about 30 minutes.

All of a sudden, the volume on my amp drops down to almost inaudible. I check out the tubes, and they're all glowing normally. After a couple of minutes, volume returns.

Any ideas?

[Shawn Lutz]

sounds like you have some output tubes getting ready to die

[VitaminG]

could be dirty loop sockets too. Try some contact cleaner & work a jack in and out of the socket. I've had this happen to tube & SS amps

[Jayster]

hehehehehehehe, I recently had a problem like this. It turned out for me - that my input jacks internal prongs had somehow gotten bent and would make contact with each other ! After finding and correcting that, I stopped having this problem. I know, strange.
I'm not saying this is your problem, just something else you may decide to look at.
Good luck finding and fixing this quickly, nothing sucks worse then you're own equipment is letting you down !
Jay

[Spivonious]

Okay, so it's probably not something internal? That's what I was worried about.

I'll take a look at the loop jacks and input jack, and if they both look fine, I guess it's time for new tubes. They are still stock...I guess 2 years out of them is pretty good.

[phill_up]

could be dirty loop sockets too. Try some contact cleaner & work a jack in and out of the socket. I've had this happen to tube & SS amps

I will never change tubes again without working contact cleaner in & out of the sockets with the old tubes! The inverter tube was the guilty culprit when this happened to me. I took the inverter tube and very gently rolled the pins closer to the center of the tube with my fingers, contact cleaner again and I have not had one problem out of it since.