Which tubes to buy

I have an ARC Reference 160s as well. My preference is to get the tubes from Audio Research... because they extensively test them and I want to support this great company. I have a spare quad of power tubes I bought from Upscale just in case I needed for testing. In general, I don’t tube roll with Audio Research equipment as they were carefully voiced. That said, a friend of mine tried a GE NOS 6550 in his ARC Ref preamp an liked it... so I ordered one just for fun.

The Tung Sol KT120s have a good reputation.

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.

@motorheadflash  I think you are making the right decision.  Why have the doubt that tat your tubes are sub-optimal when you are using one of the word's best amps?

To @motorheadflash, I agree, best to stick with the same and what your amps were designed and voiced with originally.  Best to source from a dealer who truly batch matches the tubes as AR did for your amps new.  

While I use close-matched sets of TungSol KT150 / KT120s in my own amps -and-use PSVANE tubes in my preamps and input tubes for my amplifiers, quality has been better the past two years. We'll see how it goes for the PSVANE KT150s, and time will tell, watching forums and feedback.  I'm evaluating some other PSVANE replacements now that do seem better than my prior pairs from 2-3 years ago fwiw.