If one is using 211 / VT4Cs, 845s, or 276As in a single ended amp, there is a fairly high negative grid bias voltage requirement, one alternate approach would be to add two more diodes, cathodes to the HV leads on the power tranny, cathodes tied together, going to the filter cap, then resistor divided as needed to obtained the required grid bias voltage.
These vintage power triodes require a hgh B+ voltage, 900 to 1250 VDC, the grid bias can be from -100 to -300 vdc, the 6SN7 input and driving stages run on a more "normal" 300-400 VDC, so take the bias as described above off the lower AC voltage power trannie.
One of these "beastatrons" is going to use a LOT of iron, two power trannies, a filter choke (or two) a separate 10 VAC filament trannie
and an 11 pound OPT for each channel, so this one is definitely NOT going to be built on a stock aluminum chassis. Nothing better to do during the long and cold winters around here, so why not...
/ed B in NH
Real Radios Glow in the Dark