Tubes for Cal Audio Labs Alpha Processor

I never had any trouble with my Sigma or Alpha being hard on tubes, but I was using 10kHr Telefunken ECC803S tubes. If you enjoy transparency and quiet background; they, or Siemens E83CC's(triple mica, from the 60's) are a very good bet(both very accurate, extended in highs and lows w/o glare or bloat, and faithful to the original signal). If you prefer a warmer coloration: Mullard long plates from the 50's are very popular. Either Brimar or Mullard CV4004's will cost less and still please you, if you like the Brit sound.

I've had an Alpha for a many years but upgraded to a Tri-Vista last year but I can't seem to part with it. All the years I used my Alpha I never had at 12AX7 quit and it was powered up 24/7 for years. I tried a bunch of tubes but the one I liked most at the end of the day was the Groove Tubes GT12AX7M reissue.

BTW it reacted well to changes in cabling.

Good Luck

I've had an Alpha for about 15 years - tube longevity has never been a problem for me. Tube selection has always been made based on ancillary equipment and speakers. I like a clear neutral tone, one that if it errs at all errs on the warm side. I'm presently using EI12AX7E (grey plates/steel pins).

I've also never had any problem with tubes in my Alpha.

For sound, the best I've encountered so far are Sylvania 5751's.

Michael