On Friday, March 4, 2016 at 10:24:44 PM UTC-5, Phil Allison wrote:
wrote:

I don't buy your story of the 1N4004 diode being reversed, 6550s draw over 500mA each with positive grid bias and the amp would have quickly blown up if that were the case.


... Phil

Well, when I put the diode in correctly (per the schematic), the hum reduced greatly and the amp draws about 30 watt less than before. When new caps arrive, I will try them out. Could also be that the diode was bad in the first place, not sure as this is the first time I checked it.

Peter Wieck
Melrose Park, PA