Oh the other thing too is that very few OTL amps can deliver sufficient current to properly drive low impedance headphones and control driver motion. Transformer coupled tube amps are generally much more $$$ than OTL circuits. There are some OTL amps that can drive a low impedance loads... Mad ear+, Earmax SE, la Figaro 332C come to mind. At $450 the 332C is the most affordable of the 3. I've only heard the earmax SE though, and to be honest I didn't think it was worth the kind of $$$ people typically want for it.
So in essence, if you have 35 ohm Grados (for example) and tube amps (ALL tube variety) seem like something you'd want to try, you're generally going to have to shell out a serious wad of cash just to get your foot into the door, and then of course allow extra funds for tube rolling. For low impedance, tube hybrids make a lot more sense if you are on a mid-fi $$ budget.
Going back to the tube - SS thing... I spent an hour or so today at my local Surplus electronics store rummaging through their racks of old NOS tubes, and some salvage-pulls as well. This is an OLD, dumpy-rustic looking warehouse thats been in existence buying/selling industry surplus (basically junk) for several decades... it even SMELLS old. The guys that work there are no younger and I don't think they ever take showers... probably contributing to the overall ambiance. The tube shelf in the back corner of the store is ~6 feet tall and ~15 feet long, next to an old buzzing coke machine. Its fun because whenver I go here rummaging for tubes I feel like I'm Marty McFly in a time machine. I come across as a tube-guy, but sonically I prefer a solid state Larocco PPA for my RS1. I love the way its sounds with OPA627, but honestly I don't get this kind of fun rolling solid state OP amps.
heres a pic of my son rummaging and posing with some LEDs, last time we were there together. Today however by myself, I didn't think to take a pic of the tube shelf and coke machine. Maybe next time.
Edited by kramer5150 - 1/26/13 at 7:12pm