My amp is 45 SE driven by 6N1P via IT from ElectraPrint in Las Vegas. If my health improves, I would like to visit Jack Illiano. My OPT are ubt2 from one-electron, John Atwood's company. John visits a few times a year and always has a good suggestion or two. The 45 is biased by two each 6X5GT diodes in series. The idea came from Steve Bench, on the Joe List. This gives wonderful sound. I had a 6AS7 wired diode (grid to plate) but John noticed the top end was 'polite' and suggested I remove the 6AS7 and put a battery under the grid choke. He was right, of course. The cabinet is an antique former radio/phono.