2. amps-preamps
  3. 153810-1112

Basic EL34 and 6sn7 tube recommendation.

I have a Mystere IA-11 tube integrated amp from sister company PrimaLuna. I bought it preowned and like-new 1.3 yrs ago and enjoy it immensely. It is outfitted with Electro Harmonix EL34 and 6sn7 tubes. (Upscale Audio is the US distributor of Mystere and PrimaLuna and also an EH supplier.)

Everything is fine currently, so I enquiring if I should replace with the same EH tubes when it's time, or should I use another moderately priced brand. I have no inclination to compare and roll tubes looking for the best match. Just looking for a good solid recommendation to plug and play.

On another related issue, my amp has Primaluna's auto-bias circuitry that automatically adjusts the tube bias, so how will I know when tubes are at the point of needing replacement, unless they are burned out completely. Thanks.
128x128mjcmt
jond's avatar
jond
5,923 posts
 
Yet another GL KT-77 lover here to me they are indispensable, just great top to bottom sound at fair price relative to NOS EL34 variants.
mjcmt's avatar
mjcmt OP
711 posts
 
Is the kt77 a direct drop in replacement for el34 on an amp w/ auto bias circuitry? May have to call Upscale when I'm ready.

Lowrider, I've been down the road of tube rolling with past systems, but don't care much about it anymore at 67 as my ears age. I just want good value and good sound without fuss.
tuberist
951 posts
 
MJC, the KT77 should be a drop in replacement but to be safe I’d call Upscale, they are tube mavens

mjcmt's avatar
mjcmt OP
711 posts
 
Thank you. I think I will call Upscale Tuberist. I suspect Upscale recommended the EH tubes to replace the stock factory Chinese tubes the amp came with.
aniwolfe
761 posts
 
A tube that is so underrated is the JJ EL34L ...In my amp I much prefer it over the GL KT77. If you can use KT66 variants, also consider the Reissue Tungsol 7581a. Viva Tubes is where I buy my power tubes, great service.
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