Reply To: Philco 37-650 Plate voltage

[Steve Dow]

If the voltage rises and the sound distort, if you can,
try and see if one of 6F6 tubes get cool.

Tube pins have the leads soldered at the bottom, and it not
uncommon for the solder to need re-heating.

Each 6F6 uses about 28 % of the B+ current for the whole set.