Yeah baby....I found a mate

Ironic, as I just purchased a pair of Raytheon 6SN7-GTB to try in the input stage of my monos.

Silver twins that sound as lovely as they look, perfect.

If memory serves, the Tannoys are bi-wireable. You should consider experimenting with horizontal and vertical bi-amping as well. Lots of options having the pair now.

having some trouble with the second amp I just got...This amp was modified by adding a volume knob, with a tube driven line preamp inside,,,very weird...and I am getting a hum which I suspect is related to that addition.

My first guess would be that a tube was jossled and damaged in transit. Try swapping the tubes from the good one into the new one and see if the hum goes away. If not, contact David again. Chances are he did the preamp mod himself. He'll know what's going on.

Good luck and keep us informed. When you get it figured out, I'm sure you'll be happy with the purchase. I've always been impressed by David's designs.

Thanks, I emailed him with some pictures...I am waiting for his response..

I'd disagree, as does the Tannoy distributor i've dealt with-DMT 12s fill up a room nicely-nicely sized footprint and more than enough bass. 15s are nice but the bigger drivers also mean slower response and greater overhang.