fyi, I am running a pair of McIntosh mc275 in monoblock mode with balanced cables, so, no V1 used.. . I replaced all the tubes with Russian Reissue Genalex Gold Lions (gold pin) in 2014. After 11 years, I recently tested all my tubes and the small tubes were pretty worn out, but, the KT88s still tested very high. I ended up just changing the small tubes - 12ax7 and 12at7. I took my time and ended up buying NOS vintage tubes. The sound definitely improved, but, my old Gold Lions were testing low, so, they were worn out, and I cannot compare the sound when the Gold Lions were new. My impression is that if you decide to tube roll, go vintage NOS for the small tubes, and stick with the Russian Reissue Gold Lions for the KT88s.
