Congratulations on achieving a system that satisfies you. I also was in search of an SET amp to drive my 12" Tannoy HPD speakers, in a large room.
I took a chance on an Assemblage Audio SET 300B amp, which was designed by Sonic Frontiers. After a factory refreshening of new caps and resistors, and some tube rolling, this amp has eclisped all that came before it, and gives plenty of dynamic headroom, even at its paltry 9Wpc.
With your Druids, I would think something like an SET 300B should prove to be a good match.
Regards, and enjoy,
Dan
