voltage check on new ac15-ish build

[texmextone]

newbie lurkers first post. It's a modified hoffman ac30 schemo. I'm not familiar with what the cathode follower & phase inverter voltages should be but I'm concerned about the voltages on the grid of the CF output, and the input to the phase inverter............should they be there in reference to chassis ground? the amp sounds good but bass is fuzzy and undefined. sorry for the crappy pic, I just drew on it in Ms Paint.

Thanks for any input.

[tubeswell]

Those voltages look about right to me. If the bass is flabby, you can always either:

1) decrease the capacitance value(s) of the coupling caps (esp after V1 and between the PI and the output tube grids); and/or

2) decrease the cathode bypass cap value (again esp on V1). You need to cut the bypass cap down to 1 oe 2uF to notice anything much

[texmextone]

Thanks for the reply.

So it's normal to have 42vdc on pin 2 , and 63 on pin 8 of the PI? Just seems weird to have a dc voltage on the input. Does it get coupled over from the plate by the tube? I can't see another reason for it to be there and initially thought that I had a leaky cap at the 47p tone stack or .047 PI input.

As for the bypass cap on V1, the circuit initially had a 220k plate resistor and I found the gain to be quite grainy so I went with the fender values that I knew, 100k plate load with 1.5K.25uf cathode, which usually doesn't make for unpleasant bass, so I'll probably start looking at coupling caps or lead dress problems.

My first vox-ish build, only tweeds & BF to date all of which I never had to troubleshoot so I'm really green!

Any other input appreciated, thanks.