@hickamore you should watch Michael Fremer’s The Absolute Sound tour of ARC on YouTube. They do a lot of testing and burn-in of their selected tubes for ARC gear. Most look like new production EH brands, e.g., Tung Sol 6550s, etc. ARC has built their own testing and burn-in jigs. I suspect they’re voiced well for ARC gear. I’ve always had good luck/good sound from EH Gold Lion power tubes.
ARC Select Worth Price?
Sovtek 6H30Ps are sounding woolly. Upscale offers replacement quads (apparently not matched) in various grades up to ARC Select cryo, all priced accordingly. (I have not inquired directly with ARC).
My only past experience is with 6SN7s, which can be rolled infinitely. What would veterans buy, and from whom?