EL34 upgrade

There's already a highly active pre-tube discussion thread called "12ax7 vs 5751". I think you'll find it a highly active forum for pre-tube advice. Enjoy yourself. Generally many EL34's last for about the same amount of time. Some are significantly less reliable (current production Tesla/JJ seem to have a high failure rate). Most have found that many NOS tubes seem to last much longer (well maintained Mullards seem to last forever). In my guitar playing days, I found that Mullards, RCAs, RFT's, and pre-Sensor Svetlanas all seemed to last longer than JJ, EH, or Sovtek. These are just my findings. I haven't lived with the Treasures long enough to comment on their lifespan.

And yes tubes definitely have a burn in time. Even if you don't believe the sound changes, they definitely take a while before the bias will settle down. I find the better tubes tend to take a little longer to settle down.

Yes output tubes have a break in period. With 6550's is usually 10-30 hrs. Depends on the amp and the tube.

@Qclabrat_1

Would be interesting to know which one you going to get/choose and, if possible, your impressions as well.

THX

No one has mentioned the EH 6CA7--recommended by Jim McShane as a close runner up to the new Genalex.

Jim is a big fan of current production Russian tubes. If he is saying the fat bottle 6CA7 I like them too, in some circuits, I am curently using them and I don't usually like Russian tubes other than Gold Lion. I am kind of surprised he didn't say go with Gold Lions whivh he usually likes. He also frequently recommends a 6L6 types tube from Russia with a designation that I allways forget something like 6P-3se?