EL 34 vs. KT 88 ---- What's the difference?

Some amps can use both el34s and 88s b/c they have variable bias, allowing you to adjust the bias to the appropriate level for different tubes.

Pubul57--My Dynaco mk iiis take both el34s and kt88s, but they're powering only the midrange/tweeter cabinets of my VR4 HSEs. Also, my kt88s are EH and the 34s are the winged c variety. That said, despite the fact that the fat bottle kt88s are the most pleasing to look at (not that anyone cares about that!), I find myself going back to the el34s. The difference, to my ears, is slight, and I doubt most could hear the difference if they weren't trying to hear it. But there is something special about the el34 midrange, at least in my system--not just more of it, but a different sonic character. Liquid is a word often used, and that gets at it.