Eratic tube activity
Hi all,
I have an AudioPrism four EL 34 amplifier. We built the OPT's for a lot of these amps and I consider it one of the best sounding and most reliable designs available. Not because I supplied the transformers either!
Today, one channel went down. The 12AT7 driver tube heaters were lit for that side, but not the EL 34 heaters. So, I switched EL 34's side to side. The other side tubes worked fine in the new places and the original tubes, now on the other side, worked fine too. For a few minutes.
No distortion, no ultra bright glowing, no unusual noises, but that tube set that had quit before, quit again. Same strange circumstances.
Any suggestions about what is failing? I would hate to spend the money on new tubes, since these sound great while playing, but I haven't the skill or experience to figure out what has gone south here.
Suggestions?
Bud
Hi all,
I have an AudioPrism four EL 34 amplifier. We built the OPT's for a lot of these amps and I consider it one of the best sounding and most reliable designs available. Not because I supplied the transformers either!
Today, one channel went down. The 12AT7 driver tube heaters were lit for that side, but not the EL 34 heaters. So, I switched EL 34's side to side. The other side tubes worked fine in the new places and the original tubes, now on the other side, worked fine too. For a few minutes.
No distortion, no ultra bright glowing, no unusual noises, but that tube set that had quit before, quit again. Same strange circumstances.
Any suggestions about what is failing? I would hate to spend the money on new tubes, since these sound great while playing, but I haven't the skill or experience to figure out what has gone south here.
Suggestions?
Bud