I took mulveling's advice and called Audio Research. They said they use the Tung-Sol tubes in all their power amps including the KT-170 in their new Ref. 330 mono's. They think they sound better and are definitely more reliable. I love the way the amp sounds I think I will stay with the ARC tubes for now.
Which tubes to buy
I have an Audio Research Ref. 160s power amplifier. It's almost time to replace the tubes. This will be the first time I replace the tubes in this amp. In the past I have purchased tubes for my Ref. 6SE preamp directly from Audio Research or Upscale Audio. Audio Research furnishes Tung-Sol KT 150 tubes with the amp. and also as replacements. Recently I have found PSVANE brand tubes available. Does anybody have experience using these tubes? I'm trying to get the best sound quality. Tung-Sol made in Russia have been around a long time. PSVANE made in China is new to me. Any suggestions or recommendations?