Vox AC30C2

[pnut5150]

I found it, I edit last post, 300+v on both ends r120. It is mounted on bottom side of board.

[g1]

It should be 308V on the end that goes to R74, and more than 308V at the other end.

[pnut5150]

More than 300 on the other end of r74?

[g1]

Ok, I saw your edit. Approx. supply voltages:
B+1 330V
B+2 308V
B+3 225V
B+4 190V
B+5 175V

Now back to the phase splitter and check each end to ground, R67 & R70.

[pnut5150]

R67-217.5k & 160.8k (took both awhile to get there on meter)
R70- 216.2k & 159.3k (""""""")

[g1]

Sorry if I was not clear, I meant DC volts.
And a caution, be sure to dig your probes in, there have been a few readings where you have changed from wrong to correct (missing +27V supply, R120 voltage reading 300V each side) which was probably due to poor contact of the probes.

[pnut5150]

R-67: 210.5v & 223.1v
R70: 212.1v & 223.3v
Bottoms of both resistors are scratchy sounding through speakers she I probe them.

[Jazz P Bass]

You lost me on that one!

Which tube are you measuring?

I thought we where trying to figure out why the phase inverter voltages are off.

[g1]

2 things are standing out right now. One is that the phase splitter is hardly running.
The other thing is that all the B+ voltages seem low.
1) Measure AC volts from each side of R120 to ground.
2) Check resistance of R107 and R109 in power supply area (22ohm 5watt).

[g1]

You lost me on that one!

Which tube are you measuring?

I thought we where trying to figure out why the phase inverter voltages are off.

R67 & r70, phase splitter plate resistors.

[pnut5150]

Ok, r120 with ground probe grounded and hit probe on resistor reads:
25.95 ac/v & 19.20 ac/v
R107 22ohm
R109 22ohm

[g1]

Well, I may have been wrong expecting higher B+. Those AC readings do seem high, but some meters have a hard time reading AC on large DC, and I don't know that large ripple on the B+ would stop the phase splitter from running.
As I don't think you've tried any tube swaps yet, try swapping the phase splitter with one of the other 12AX7's and re-check the voltages at R67 and R70, same as in post #52.

[pnut5150]

Yea I put a whole new round of preamp tubes in, no change.

[pnut5150]

It's odd, sometimes when strumming the guitar, it tried to get louder briefly. I do have a signal generator app on my phone I use with a 30mhz dual trace scope if that helps??

[pnut5150]

Anything else?