Thanks! I can use EL34s, though the manual says I'll lose a little power. (Given that my amp is loud enough for the neighbors to complain with the dial at 10 o'clock, I'm not too worried about that, though.)
What do you think of the Winged C KT88s? http://www.upscaleaudio.com/tubes/kt88/sed-kt88.html
Thanks, Porcy. I'm bidding on a pair of Telefunkens on ebay right now, but they seller has 100% positive feedback from nearly 1000 reviews (including lots of tubes), and they come with the original boxes, so hopefully they are legit.
I'm of the impression that NOS isn't as important for preamp tubes, because they draw so little power to start with so they have much longer lives. Do you agree with that?
I definitely plan on trying lots of different types, but I want to pace myself. I am, after all, standing at the top of a long, steep, slippery slope!