Hi,
I was away for many weeks, now I’m back with the HD621. Haven’t used it yet.
It’s connected to the G61RSL with 3 cables to MD1. 1/2 to L/R, 3/4 to C and 5/6 to SURR.
DIN comms are also connected between the two units.
Now, what will be the benefit having the comms connected? Input switch I assume from remote?
Thanks.

G61RSL, DSP7200, DSP5200HC
Lumin D2
Akai GX-620, Teac A-3300SX, Nakamichi CR-4A, CR-2A
Oppo BDP-103
Sony PS-X600, Nagaoka MP-110, Denon DL-103R
NuPrime STA-9, Elac BS 63
PS Audio PP10