[Radioroslyn]

Just for the fun of it if you would like to experiment a bit to remove hum disconnect R-100 and replace it with a small iron core choke. This can be one from a power supply, the HV secondary from a power transformer (disconnected of course) or it could be the primary of the tube type audio output transformer. Two things will happen one is that a choke is much better in filtering than a resistor and the other it has less of a voltage drop. So you'll get less hum and a little increase the voltage.

Terry
ps Grew up near where your bro lives. I'm from Sandy Spring about 15min from the other SS.