Audio Xpert. They seem to be full line service. I'm guessing they can look at your tubes. I bought a Threshold amp from them a few years ago that still sounds wonderful. One challenge if you have "some" bad ones is matching new with what you have. I have always just bought all new when anything goes a bit sour.
Need tubes tested Las Vgeas Nv
I have 12 Kt120 used tubes test before I used them in my $$ amplifier
any body know of guy in las vegas to show go/no go on tubes??