I was going to put a whole load of stuff on ebay this weekend, but if you want either the rhondo or the Rhythem I would be happy to hold it for you until Friday. I rather they go to a good home
oops, just checked the minidisc player out on the net and it only has optical so i'll leave it sorry. Don't suppose you have a good quality optical lead for sale instead?
Can't help you there I'm afraid. But if I was you, I would look for a Van Den Hul Optocoupler (£50rrp but can be picked up new for £35 on ebay). This is by far the best optical cable I have tried (and I've tried a few!) In fact its the only one that really made any difference at all.
Best of luck