I'm rebuilding an old PP 6L6 PA in to something with a vaguely Marshall front end, and I ran into a weird power supply. Can't quite figure out what's going on. It has a PT with a 145V secondary and a voltage doubler. It's almost like a typical half-wave voltage doubler, but not quite. I've retraced it like 5 times because I'm sure I got it wrong, but no it's right. Schematic attached. Seems to be missing a series diode, and I can't figure out what that other diode to ground is doing. Or why there's that 5.6ohm resistor in there. I may just leave it alone since it seems to work, but I'd like to understand it better if anyone can help explain what's going on, thanks!