Yes it is a bit clunky and yes, it uses BNC connectors but RCA to BNC adaptors are readily available, personally I would chop off the non 75Ohm phonos and replace with pukkah BNCs. (THAT will test your cable building skills!)
But if you are of a DIY bent, 3 RCA sockets in a tin with a submin switch and Bob is yours! Or, simply make an RCA/phono breakout/patch box and plug up as required. I have two PCs linked via S/PDIF and one link comes out to a box with a 100mm patch loop so I can go into one PC or out of the other. Then again you might find a "star splitter" will allow S/PDIF to feed both inputs? I think the resistors are 27R for a 75R system but I could check that.
Optimum is in fact 25R but I doubt that 22 or 27R would make much difference.
Edited by ef37a (02/05/12 07:12 AM)