Since the cables won't be put long distance and i 'only' want to listen to refference mixes, not for QC Blu Ray purpose. It might be reasonable to connect unblanced Rca to dsub, or want do you think?
There are even retailers offering this type of cable:
https://www.ebay.ie/itm/25-Pin-D-Sub...8axnOYBsyv3gcw