Ah right that explains it. From the circuit diagram of my amp. Wishing to feed the 150k plate resistors with 250v rms or approx 350v peak. The amp was designed to drop about 100v across the plate resistor so the tube was fed at about 150v. Therefore plate current is about 100/150k or 0.7mA. This checks out on the valve curves using grid voltage of -1.25v and a cathode resistor of 1k8, gives voltage of 145v and a current of 0.7mA.
Now on to the spice load resistors. Require 250v at 0.7mA which means they should be 357k. Selecting nearest standard value of 330k to load each stage, I can change the values of the filter resistors R2 and R5 to get 350v peak on the traces.
Now on to the spice load resistors. Require 250v at 0.7mA which means they should be 357k. Selecting nearest standard value of 330k to load each stage, I can change the values of the filter resistors R2 and R5 to get 350v peak on the traces.