Go over to Audiocircle.com and check out electronic engineer Roger Modjeski's exposition about 6DJ8/6922 differences in the Music Reference section of postings. Basically, there is not any substantive difference. Depending on manufacturing tolerances, a batch of tubes can be labeled either 6DJ8 or 6922. Aural differences exist within this family of tubes of course, but don't focus on 6922/6dj8 as a factor of sonic differentiation.
Best 6DJ8 tubes?
I have a Carver C-19 pre and SDA/490t cd, both use 6DJ8 tubes. Both units were recently serviced and had Sovtek tubes installed. The tubes in the cd player only have about 10 hrs on them, but the sound isn't nearly as warm as it was before replacing the stock tubes. I was wondering if anyone could recommend the best brand I could use, if 6922's would improve the sound, and the standard burn in time for the new tubes.