Mojotone Princeton B+ voltage way low

[RadioGuySD]

That's impossible with your transformer voltages.

Is your meter battery good?

My Fluke 45 bench meter doesn't have a battery to my knowledge. If have 700vac off the transformer why is a B+ voltage of 500 and some odd volts with no load impossible? According to the schematic I should have 390vdc at the board with a full tube complement.

The "I" terminal of the HV cap is definitely connected to chassis ground.

[Enzo]

The impossible was the 600v you reported in post #18

[Helmholtz]

If have 700vac off the transformer why is a B+ voltage of 500 and some odd volts with no load impossible? According to the schematic I should have 390vdc at the board with a full tube complement.

Max. no load DCV with 2x350VAC is 495VDC.

[The Dude]

For the curious:

This amp just came into my shop, so I thought I'd update the thread with what I found. One of the rectifier filament wires was stuck into the socket pin, but not soldered so making a very poor/intermittent connection. I circled the pin on this photo.

[pdf64]

Good find!
That chassis safety earth looks like Bubba done fixed it

[The Dude]

Also found a broken connection to V3 grid. The wire was soldered, but had broken right at the point it goes into the socket pin. Probably just cut in too far when stripping the wire and actually cut the wire. The amp is up and running properly now and actually sounds really good.