ST-70 Rectifier Voltage Readings

One of my ST-70s developed a bad buzz and just all around poor sound quality compared to my other ST-70.

I decided to check my voltage readings to see if anything was unusual. The rectifier pin 2 and 8 readings to ground are about 325 V which I understand to be ~ 100 V too low. The voltage readings on pins 4 and 6 to ground are 0.1 mV which I'm assuming this is how my meter reads 0 V.

The voltages on the quad cap and EL 34s are correspondingly low. For the EL 34s, the readings across pins 2 and 7 is 0.2 mV and pin 3 to ground is 0 V.

The quad cap readings range from 276 V to 325 V.

I'm assuming that my power tranformer is toast?? Should I be checking anything else?

Thanks

Thanks Bob, you were right I was measureing DC. Pins 4 and 6 measure ~383 VAC.

I switched rectifier tubes and ruled that out as a source of the problem.

These are the out of spec readings.

Output tubes:

Pins 3 and 4 ~ 319 VDC - all tubes.
Across pins 2 and 7 , no measurable reading - all tubes

Quad Cap:

Lug to B+ voltage ~ 284 VDC
All other lugs ~ 322 VDC

Does this sound like the problem is the quad cap?

Thanks

Thanks Bob.

There is a reason I don't do this sort of thing for a living. Quad cap is on the way.

Best