Before you wonder away $975 on three pinched waists try Amperex 7308 PQ White Label 60's or USA-CEP's, very close to the PW's in my system, at a fraction of the price.
Tube Rolling In Audio Research Phono Preamp
I have an Audio Research PH3SE phono preamp that currently has three Sovtek 6922's. Audio Research told me not to bother doing any tube rolling because it will change the "voice" and tone of the preamp. However, I keep reading wonderful things about vintage tubes improving the quality of sound in all kinds of gear. I was wondering if anyone has had any experience with different tubes in their phono preamp and which ones they liked the most. Thanks!