Upscale Audio has a very rigorous tube testing and matching process. Unless you have money to throw away, I’d definitely purchase tubes from Upscale Audio, or Jim McShane. I have more experience with Kevin at Upscale Audio, but Jim McShane also has a top-notch reputation and I’ve received great tubes from both of them as well as Tube Depot. But Upscale clearly has a more rigorous screening process then Tube Depot, that’s for sure. Kevin told me at the Newport show a few weeks ago that he rejects 65% of the Russian tubes he receives as the Russians sell everything they manufacture regardless of how they spec out. Have no fear buying tubes from Upscale or Jim McShane. Btw, I own a ARC VS-55 and I use the hell out of it. It’s a daily driver, and as such, I go through tubes regularly.
Tube advice
I have several decent, newer ARC tube amps and will soon be approaching tube replacement time. ARC apparently has a very thorough vetting process for the tubes they install and sell. That of course runs a hefty premium, more than double what the same tubes would cost from Tube Depot etc. The money's not a total deal breaker but still, for all three amps re-tubing from ARC is going to run close to 3k and if it's all the same would definitely rather not have to spend the extra $1500. Any insights would be appreciated. Thanks