Re: pentode vs triode
N-E-WAYZ. . .
It depends. I can see how pentode works in a big amp when you want nice, fat tube dynamics, and more headroom.
I can see how triode works when you want a little more sag, a little more grind.
But when you crank the amp, you can't hear all that much of a difference, so it only reall matters when you're playing at lower volumes.
I think a 100 watt tube amp in Cathode bias mode is the way to go. It's hell on the tubes, but you get TONE.