Yeah baby....I found a mate

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.

Give me a break, Slower response?...I would figure that an educated speaker guy from Tannoy would be ahead of such "folklore"...or is it the speaker fairies?

Yes genius, that's right. Free advice from someone who knows as well as a Tannoy dealer who knows better than you. Very doubtful that more bass than the 12s throw out's necessary unless you're reliving your teen metal phase, but if more's needed just throw in a sub.