Filtering help on a Dirty Shirley Marshall Style amp...

[g1]

I see that too. But sometimes in pictures the oranges & reds can come out looking brown or black. Or it could have got hot and discoloured. 820 in series with 470K for a voltage divider would leave you very close to ground.
Also, the post you linked from sloclone forum called out 82K.
Working with an example of 350V supply node, with 470K series resistor, 82K would elevate you to 52V. An 820 would elevate you to only .6 volts. 82 ohms there would be basically ground potential.

[cluster]

Did you use ohms law to calculate the elevation voltage? Also, would there be any harm to the PT due to the extra load of elevated heaters?

I see that too. But sometimes in pictures the oranges & reds can come out looking brown or black. Or it could have got hot and discoloured. 820 in series with 470K for a voltage divider would leave you very close to ground.
Also, the post you linked from sloclone forum called out 82K.
Working with an example of 350V supply node, with 470K series resistor, 82K would elevate you to 52V. An 820 would elevate you to only .6 volts. 82 ohms there would be basically ground potential.

[Enzo]

Also, would there be any harm to the PT due to the extra load of elevated heaters?

WHAT extra load?

[g1]

Yes, ohms law, typical voltage divider equation. R1 divided by (sum of R1 and R2). Multiply that by source voltage (350V was used in example).
There is no extra load. No path to ground through the transformer winding so no extra current caused by the elevation. It's like a 'bird on a wire' no extra load on the electrical source, no stress on the bird.

[cluster]

That's what I read. Tying the AC to the HV.

WHAT extra load?

[g1]

I guess there is a trickle of current through the voltage divider but it is miniscule, less than 1 milliamp in the example. Not worth calling a 'load' in relation to the current this PT can supply.