Custom build in Hammond Al Chassis

[Raybob]

I've built a AB763 w/no trem, single channel, in a Hammond chassis. Drilled all holes for tube sockets, pots. etc. to get everything in small chassis.

Sounds good up to a point. Watching the signal, looks good at lower volumes but when I reach 6 pm Volume, one side of wave goes wonkers, Stays wonkers until I drop volume to 5, then clears up.  I'm watching signal at 1st plate.  Same happens with plate of 2nd stage, different wonk but same problems at same volume level.
I have signal from input jack in double lead shielded cable.  Other lead in cable is from wiper of volume pot.  At v1, one lead connects to pin 2, other to pin 7.  I'm suspecting that may be the trouble I'm having because it's two different signal wires running parallel.  Is that a no-no, or should I take pics and try other ways to find this problem.

[sluckey]

Use one cable to connect signal source to input. Use separate probe(s) to view signal on scope.

Turning the volume pot should not affect the signal at the first stage plate.

What is the signal level you are connecting to the input jack?

[Raybob]

What is the signal level you are connecting to the input jack?

I'm using 100mv AC, 432 hz