Question About Signal Path Voltages

[Cosmo]

Been using the scope to look at signal path voltages under varying conditions. It's experimentation and education.

Does anyone know what the "normal" gain range at V1-A and V1-B is for "typical" amp? Something like an old Fender where the fist triode is input gain stage, followed by the tone stack and vol, followed by a gain recovery stage? Basic early Fender design with only two gain stages.

I have a 6G9 EL84 Tremolux clone I'm building. I'm testing with a 2.5Khz wave at 500mv (similar to my PAF humbuckers). The signal after the first triode and a 250pf coupling cap is 12.9vac. With the volume dimed, the signal after the tone stack gain recovery and a .001uf coupling cap is 87.5vac. That's almost a 7 fold increase. Is that reasonable? The tube is a 12AX7B.

I ask this because the amp is extremely microphonic at the grid wire of that second triode.

Any thoughts?

[Cosmo]

Follow up. I solved the microphonic problem. It was a bad piece of shielded cable I used for the 3" - 4" run from the vol wiper to the grid of the tone stack recovery triode. I use Belden 88641, but there was something wrong with this piece. Replaced it with a piece of regular wire and the problem is gone.

That was not an obvious component to fail!