Ampeg SVT CL valve's

[Mr. Foxen]

Dying caps can go pop, you'd be looking for swollen ones as an indicator.

[Anders]

Or could it be a preamptube or even the new 12ax7 tube? I'm not sure,but i've heard preamp tubes going bad making all sorts of different sounds,also bad cables(especially fried egg-sound).Just a thought.

[VTypeV4]

+1 on giving the bottles a gentle tap.. Any instabilities with the valves themselves will quickly be apparent.

[Bobo_Grimmer]

Morning, I've given them a dink and nothing noticeable happends. Ive changed all 6 power vavles and put the original 12AX7 back in and biased them. Still the same noise. It varies in volume and stops and starts.
It's made a pop sound only once, that caused the service light to flash. Hasn't done that since. I've ran the amp with both cabs, one can and left it on for a hour or so and no change. It's not doing it when sat on stand by.
I am headed out to play an open air festival in b'mouth today and I guess we'll see what happends.... I have to say I'm concerned. it's still under warranty so I can see about gwtting it looked at. Thank you for all you help guys. I appreciate it a lot.

[Mr. Foxen]

I recall a guy's ampeg doing the same thing and that was toasty caps, bit older though.

[Bobo_Grimmer]

Hum... well during sound check today it popped. When distorted and the two au7's blew. Off for warranty I guess...

[Mr. Foxen]

Should really go as soon as starts misbehaving. Using a malfunctioning amp never goes to good places.