difference between 6922 and the 6h30 super tube

If you go to the Balanced Audio Technology site, there is some good info on the 6H30. Also the owner, Victor, is a very nice person to speak with.

Pins are the same, but I understand the heater currents are different. Apparently, you can not substitute one for the other.

6922 is more refined, smoother more musical than the 6h30. The 6h30 can also be call supertube is more dynamic and transparent but not as much musical and smooth as the 6922 and sometimes is very dry and analytical. Also there is so much more choices for the 6922, if you are chosing the 6h30 tube you will be stuck with them since there is no choice to roll the tube.

Goone is somewhat correct. I own BAT gear with and without the 'Supertube'. I would say that the 6H30 is more dynamic and transparent than the 6922's, like Goone said. The only difference I would say is that the 6922's CAN be smoother and more musical, but only NOS, not the Sovtek's. I have Amperex 7308 PQ's in my VK-P5 (Mullards were actually too warm and mushy). The 6H30's are not for those that crave 'tubey' sound. IMO, they sound like a hybrid design. They have more warmth in the mids than typical SS (not all SS), but they are more dynamic than typical tubes.

They are not interchangeable, due to differences in plate voltages the system has to be designed to use each specific tube.

I hope this was somewhat helpful,
John