Signal path in Concertone

Hi, still working on this pair of Berlant Concertone preamp conversions. I’d like to do away with the signal selector pot (R 121 on the schematic below, connecting V101 to V104) and use it as an standard output volume control.

My problem is losing the signal path, and where I’d put the pot in that path. I traced it to the best of my abilities (yes with my children’s colored pencils) below, switching from yellow to pink whenever the signal is inverted. I’m not totally clear on what’s happening at V104 though. I assumed a cathode follower feeding the HiZ side of the output transformer, but I’m not clear on how it’s sending a balanced signal.

If someone can clear that up for me and suggest a value and placement of the output gain pot I’d be grateful.
Best
Ryan

rphancock1 said:

I’d like to do away with the signal selector pot (R 121 on the schematic below, connecting V101 to V104) and use it as an standard output volume control.

Click to expand...

you can change R121 to a common 100k audio taper potentiometer,
or keep the original control; move the ground connection to the repro/playback side.
this is the output control.

break the connection from the reproduce circuitry.
break the connection to the record circuitry.

that's what I did:
yellow is Line input, Red is V1, blue is V4. When you want to use the VU Meter, you need V5 also.
I left off the bypass switch after the OT and went directly to Pin 3 of the XLR.
Try it also without the OT, maybe you like it better.

Thanks, Kosi that drawing is super helpful. I had the cathode follower path wrong in my head. I see now. I really appreciate the info and the time to draw that out.

Gridcurrent thanks for the info on the output pot.. I’ll do what you suggested. Thanks so much!
Ryan