About AMP cable and move it, it's not easy. Anyway, there is a console in use in same cable, so all pairs can not be bad.

Regarding input matching, MUZAK (Music On Hold provider) installed an amplifier in line with output of 600ohms, so it not should be the problem. Also, I'm able to hear music with my butt set on all pairs used so far (R/O, R/S, V/G).

Why do you ask about two consoles working? Thinking on replace console module for MOH module?

THANKS.