Did a quick search and found nothing, so sorry guys if it has been asked before. And again if it's a n00b Q, amps aren't my thing!

# The valve line-up in a 100 watt amplifier is shown in pairs - 2 on the left (1 & 2) and 2 on the right (3 & 4).
# When replacing power valves in matched pairs, replace (1 & 4) and (2 & 3).

Is this true for all 100 watt valve amps?

If so, then I've got a problem. I can get about ~5mins playing time before I hear a pop through the speakers and the sound dies. I think it might come back on a very low volume, but I don't leave the amp on long enough to find out.

My valves are fine, I've had them for a while though (bought the amp in 2006, played it heavily until mid/late 2007 since then it's been collecting dust 'till now). I had a tech take a quick look at them also, he said they were fine too. Guitars and cab are fine too.

It's an Ashton VP100H amp. For those that don't know it, it runs 4 EL34s and 4 12AX7s. 100w.

Any thoughts?
So did you recently change the power tubes or no?

Your problem could be the preamp valves. I doubt it is a fuse. Could be a bad joint some where, or your power tubes are going bad despite what your tech says.

Nope, haven't changed them. Just took them out and put them back in.

I noticed there were numbers on the valves (03 07/08) so I reordered them according to the values I quoted. It doesn't pop anymore, but there is an immense amount of interference (kinda like static...but not static - and its loud) and it comes in within the same timespan ~3mins.

EDIT: I might have to eat my words, I've just played it thoroughly for ~2hrs with no dramas. All I did was take a valve out, and put it back in. Maybe the connectors were dirty or it wasn't in properly...or maybe the order fixed them.

Thanks for your help! I'll get new tubes all round anyway, if anything they should make the amp sound a bit better and have it last a bit longer.
Last edited by fendersquier666 at Nov 5, 2008,