Go to Vacuum Tube Valley [www.vacuumtube.com] and get the back issue number 11 from the spring of 1999. Most of this issue is about the 6SN7 and while parts of it are over my head, there is a very nice one page article which lists and rates over 20 6SN7 tubes. I have used a few differant Sylvania 6SN7s in my AES(cary) AE3 preamp and am very happy. They rate 3 differant Sylvania's and two differant Tung Sol's
Happy Listening
Woody
Happy Listening
Woody