I have JJ El34s, old Svetlana EL34s, really old Mullard EL34s, and Siemens EL34s.
The JJs and Svetlanas sound about the same; they both test good. The Mullards are out of commission as only 1 tests good. The Siemens sound wonderful.
It is interesting because I have read that the JJ KT77s and E34Ls sound better than the EL34s from JJ. I have also read that the Svetlana Winged Cs sound great. And, I have read that the new issue Gold Lion El34s sound great. It seems, from the reviews that Gold Lions are magical.
From my experience, the Siemens take the cake. The Mullards were magic before they died. The Svetlanas were very, very good, but they have aged. The Siemens EL34s are awesome. They have such air, clarity, timbre, and depth of soundstage. I really enjoy listening to my system with these tubes. The JJ EL34s sound reasonably fine, but in comparison to the Siemens, they are flat, lacking in timbre, and totally lacking in depth. The JJs also don't sound as smooth in the highs, nor as deep in the low frequencies.
I truly wonder, could JJ's KT77s sound much better than their EL34s? Also, could their E34Ls sound better than their EL34s?
The Siemens are special, and have the magic. Do JJ's other offerings in the EL34 variety have it, too?