[codefox1]

A healthy 80 can handle 650 volts Okay. Make sure the voltage divider and capacitors are able to handle the load. Beware of polarity in filter capacitors, CT of high voltage may be negative with respect to chassis to provide bias, and therefore the + side of it's capacitor would go to the chassis. Double check schematic to be sure you have it wired correctly and best use a variac to bring the set up slowly whilst monitoring B+.