look for tad 1000k mono tubes or tad-60. paul uses 60's technology, with some sprucing up of his own creation, to give what he might say is the king of 60's hifi sound. i run my monos with the tad sig 150 pre-amp with a pair of acoustic zen adagios in my office.
work is hard to stay with, but it draws me to actually show up. all in all aw great sound. you do not have to suffer with the problems of old amps. a nice hobby if you do the work, to get thawt sixties tube hifi sound.