lonote wrote: ↑Fri Feb 07, 2025 5:06 pm
I am not sure which 100K you mean, as there are 4.
Haha! My mistake again. I was looking at a slightly different Supro that was drawn more clearly and it had 270K plate loads rather than the 100K in your circuit. The 100Ks tied to the plates are the plate load resistors. None of these four 100Ks has anything to do with filtering the LFO tremolo signal.
When I look at that schematic, I am seeing (rightly or wrongly) a 200K total plate load on each triode, but with that .05uF cap to ground at half the total resistance, presumably as a filter of some kind. That seems like a larger value cap, which made me wonder if it was LFO related.
The 100K that is connected to the B+ line is actually just a B+ dropper. It's not part of a split load plate resistor. The .05 cap at the junction of the two 100K is a filter cap that puts that junction at AC ground. So all the plate signal is felt across only one of the 100Ks. If you remove the .05 cap then you have a true 200K split load and half the plate signal will be felt across each resistor.