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.
