Just for fun, I checked my plate voltage and got 372VDC when in normal stereo mode. 370 is published spec by Dynaco. When I yanked the two outport tubes in one channel to force the amp into quasi mono, I got 398. I checked all other points and they were all up, very close to a factor of 398/372=1.07, being the difference between the plate voltages. For example, the stereo reading for the plate (pin 1) on the 12DW7 was 221 in stereo and 235 in mono. Cathode was 0.84 and 0.9 respectfully.
Wall voltage was around 117VAC.
And of course all the readings at the B+ points were up a factor of 1.07 as well. If I were to go the mono route, I kinda' know what to expect now. If I want to get close to Dynaco's specs, I would have to get a different power transformer - maybe a 310-0-310 - or possibly use a GZ34 rectifier or something.
Dammit Corndog, you've got me thinking now!