audio Research REF 110 and KT 120 tubes

I would be interested in the answer as well. Thx

Lostbears...ARC told me the same thing. They also said that since they are drop in replacements (i.e., no change in bias settings from when the 6550s are in the circuit), they are being run much more conservatively at the existing bias settings so that the tubes should last longer and theoretically they are expecting less in the way of tube failures. I recently had my Ref 110 retubed by ARC with 6550s so I will probably just wait before retubing again with the KT120s.

Hifigeek1...is there only one supplier of the KT-120s? From my conversation with ARC, they said they are not selling the KT-120s on a standalone basis for existing customers to retube their current production amps because they barely have enough supply to meet new amp deliveries that come with the new KT-120s. So it sounds like supply is pretty limited. Did you get yours from ARC or from a third-party tube vendor? Thanks.