I do not understand how this could work with MCL.
My situation is: BM4500 in the main room with attached Phono, Tape and CD, a MCL cable connecting 2 MCL2AVs + Beolabs / MCL2P in the linkrooms.
The intention is to use another BM4500 in a further linkroom, to play either its local sources or sources from the BM in the main room.
I see only 2 possibilities: to connect the BM in the linkroom either with the MCL cable, but this would electrically interfere with the BM in the main room, or with a MCL2AV via the AUX.
Thanks for your patience, Herbert