This one does not drive the cathodes, or even run to grid current. It is a PP DHTetrode design. Cascode input stage. Diff amp/LTP phase inverter which is attached to the finals( 1624's a glass envelope 1619 ) with the E-Linear cicruit. Two stage amp, single B+, and a valve rectified L-C filter. I am shooting at SE 300B power, with sonics which will cause SE300B amps's to undergo a ballistic trajectory flight in the direction of the storage bin.I am not certain that the cathode drive has merit. Perhaps for a more ocnventional design, but I think I have a bit of research and experimentation to do first. I also think 70W from a pair of E-Linear rigged 813's will be of higher quality than a cathode driven pair of 211's ( not to mention more powerful and lower output Z ). As proof of reasonable potential, I keep comming back to the 813's.
I have heard the arguement that they don't like U-L connection, but I figure if they can survive as triodes, I can run them U-L/E-L
I did favour you with a reply to your note. I am not sure what you meant by 'chat at vintage'...
regards,
Douglas