The output valves can only be operated in Class A. If the first output valve in the signal chain is driven to cutoff, there is no drive signal for the second valve.
Wow, that is nearly identical to the circuit I am working-on! I can see now that my thinking was correct: the screen of the 2nd output tube (who's grid is driven by the screen of the 1st output tube) should be connected directly to the screen supply. ONLY the 1st tubes screen gets the 4.7K placed between its screen and the screen supply.
extra simple, the variation is from where of how the inverting grid is sourced.
looks like a 12au7 moon light or a lunchbox scaled up, but its the other way round, I've built this one on 50w iron and kt88, ripping harp rig..
the previous look a bit like an ultra path, its what you use as feedback to linearize and extend bandwidth
