Craig: I recently picked up an Audion 300B stereo amp that uses (one) 6922 and (one) 5687 as well as a pair of 300B's. I have three sets of output tubes so far (stock Chinese mystery tubes, Svetlana's and JJ/Tesla's) and find that I prefer a different 6922 with each set of 300B tubes. The sharper sounding Sovtek or better yet the old production Soviet 6H23EB with the softer Svetlana 300B's and the old fuller/softer sounding Amperex PQ and standard/USA white label 6922 with the more strident JJ and Chinese 300B's. So, I am comparing the sound of these combinations of tubes. It's kind of funny in that I never rolled tubes in my hifi amps in the 70's and 80's but I did roll them in my Fender Guitar amps in order to get the sound that I was looking for. It's a lot more difficult to chose now that I am not basing my opinion solely on the sound of a Strat or Telecaster. LOL. I am also trying out different 5687's with black plate designs. Sylvania Gold murders the mystery National 5687 that came with the amp (which sounded very murky) and I have a Tung Sol black plate 5687 on the way. The Tung Sols are readily available but I see people paying very high prices on Ebay for them. Go figure. There are a couple of people that I met on the web that also have the Audion Silver Night and we will be pooling info as each of us try out different combinations. I have also found that it helps to clean the pins on the tubes with alcohal and if needed a brush.