My Laney Ironheart 60H is acting up. Truth is, it's been headed this way for a month or two, now.
Every so often, I'll get a really decent hum or buzz going - usually after the head has been on a while. Then, it'll suddenly start feeding back a little. I can reproduce the hiss/buzz with or without the effects loop connected. The feedback issue - not a scream or squeal, but rather more of a groan that gets increasingly louder until you flip the amp into standby - really only happens when I have an overdrive going.
It's not consistent, though. Sometimes, I can turn it on for a short time and have no issues.
Choice of guitar doesn't matter, choice of cable doesn't matter, etc.
I'm thinking tubes.
So, also open for testing suggestions, I'd like recommendations for tubes: brands, etc.
I'm considering switching from 6L6 to EL34 power valves.
The others are 12AX7.
EL34B. Do it.