I have experience with the Elecro-Harmonix EL34, he JJ (Tesla) E34L, and the Mullard EL34. The Electro-Harmonix is quite sloppy in the bass compared to the other two and is rolled off in the treble to the point of sounding muffled. The JJ is more extended at the frequency ranges but lacks the presence of the Mullard to obvious degrees. It's the best compromise but the Mullard is the best tube, easily commensurate with the attendant premium.
Opinions of Electro-Harmonix tubes?
Anyone try tubes from Electro-Harmonix? Would like opinions of their tubes (especially those of 6L6EH Power tube). How do their tubes compare with Svetlana or Sovtek power tubes? Thanks for the opinions. Their stuff seems reasonably priced and their claims are that they are just as good as current stuff or NOS in alot of cases.