I often toy with the idea of screen modulating one of the Russian tetrodes. Even the big jobs like the GU74 and 84 are still pretty affordable. Imagine a screen modulated GU84B? Use the QIX concept: low impedance cathode follower and negative peak limiter. No sweat legal limit, gonzo positive peaks!
Gu34b has any one played with these Russian girls? They sure are cheap. I got a couple with sockets not sure if i want to put the time into them. I have built with the Gu74 great tube.
Johnathan N8QPC