After all the hype back then on these, I decided to make my own pair of monoblocks way back then, at back breaking 35kg each even with aluminium chassis, also feedback adjustable, and very high quality transformers, power, output, chokes, and interstage.
They consisted of 13d3 Birmar input tube (same Audionote used in their top preamp) then a 12BH7 strapped RCA blackplate driving a Sylvania 300B which then drove the interstage transformer which drove the 805 RCA black plate tube.
These just drove the ESL section of the Martin Logan Monolith III's It was nice even good, they lasted about 6mths before I sold them. I may still have the circuit diagram on an old backup HD somewhere if anyone wants to make a pair, mind you these are lethal!!!!!
Cheers George