I built a version of the DCPP six years ago, and use it every day. It is the best sounding amp I ever built, and I have not built another amp since getting it done (started one but stalled). My version is point to point wired, with 12 tubes (nothing succeeds like excess): That is two damper diodes to rectify, four tung sol 3cb6s (odd heater voltage tubes are cheaper), four 6GV5 output tubes with caps, and two 6sl7s that serve as the four feedback resistors. As John Broskie said, the Schade style feedback makes Pentodes sound like Triodes. I used some old Heathkit output transformers and a honkin EICO power transformer, and a bunch paper in oil capacitors in the sound circuit and motor runs in the rectifier part. The thing weighs a ton, and looks steam punk, but sounds great. My all in cost was $210 then (if memory serves - half of that for the Heathkit output transformers), but it would have been smarter to save hours of work and buy Pete's circuit board.