Well it's that time of year and I'm ready to roll. Tube roll....that is!
HH Scott 222c. I've tried a few 6U8's in the past and kinda settled on the Tung Sol's but there's many I've yet to try. Like some Telefunkens.....
While you are rolling, try some 6GH8's. There's enough difference between that and the 6U8 that you may notice a difference, even if the two are show as subs for each other.
If your amp has enough filament current try a 7687 tube, same pin out made by sylvania. I am using 2 in the front end of my Dynaco ST70 wired for 6U8 or 6GH8. Also look into the ECF82.
Well, I went through my stash and evidently I have quite a few variations of the 6U8. The clear winner at this point were the Telefunken ECF-82.
Man I gotta say that rolling tubes in a Scott 222c integrated is a blast. 11 tubes and the different combinations giving varying results really cranks this hobby up a notch.