It was pure lust and love at first sight. I found the RL12P35 german transmitting pentodes and couldn’t resist in buying them. A very nice set of NOS Telefunken and Valvo valves with also NOS sockets. These pentodes look like a de-rated LS-50/GU-50 and very interesting candidates for a nice PP amp:
RL12P35 valves
Note the Nazi printing!
These have been used by Lorenz to build the classic and lovely PP amp LVA/BA30 RL12P35 Amp with anode to grid feedback (i.e. a la Schade) like the below amplifier:
