Obvious answer is Ei
9 responses Add your response
Please excuse my possible incorrectness, but I didn't think Ei produced an EL34. They do make a tube which can be substituted in many circumstances, the 6CA7. In my travels, I have found that the best EL34s these days are from Svetlana and JJ(formerly Tesla and Teslovak). The Svetlana is by far the softest, sweetest, and most warm. The JJ tubes are more strident. If your system tends to brightness, I would recommend the Svetlana. If you have a soft or neutral system, I like JJ. The JJ is the most balanced of the current EL34 to me. JJ also makes another version of the EL34, the E34L. It is more powerful, with better bass response. A very nice sounding tube indeed. My very limited impressions of the 6CA7 were that it was closest to an E34L in sound.
Dear Trelja: The 6CA7 is the American number for the EL34. It might be interesting to note that the 6CA7 pentode was manufactured in a metal shell envelope, similar to the metal 6L6 tube; I am not sure, but I think Sylvania was the maker of this tube. The suppressor grid (grid #3, pin #1) was connected to the shell inside the tube. This was around 1960-63. This tube had to run hot as hell!!
Lindeman5, thanks for your information! My Jadis takes a wide range of tubes: EL34/E34L/6CA7/KT88/6550/KT90. I always went around saying the 6CA7 was equivalent to the EL34. This is what I had been told, and did get these for a friend who needed an EL34 retube(and wanted more punch - said he was happy with the tube). However, Jadis once corrected me, saying that a product(not my amp) they make is OK with EL34/E34L, but not with 6CA7(maybe the reasons you alluded to above). So, since then, I have been hesitant in recommending the 6CA7 to people in lieu of the other. I did hear a Jadis with the Ei 6CA7(I think this is their only fore into the EL34 market), and thought the sound was much more punchy, dynamic, big, and less sweet than the JJ or Svetlana(especially) EL34/E34L tubes that I have a lot of experience with. Was this also your impression of the 6CA7. But, it may be particular to Ei output tubes, as the KT90 exerts the same characteristics when compared to the 6550 and KT88(especially). When I retube(now using Ei KT90), I will be going to a sweeter tube, and have yet to make up my mind whether it will be the KT88 or E34L. Perhaps, I may try the 6CA7... I have plenty of power to sacrifice(to make the step down to EL34/E34L/6CA7), as I don't really run the amp past 9 o'clock. Thanks again.