Seems this is a proprietary connection system intended to work with the Turtle Beach soundcard in a Dell computer. That sound card can be switched to send SP/DIF over the VersaJack, the yellow Centre/LFE connection. So looks like you'd need an adaptor to connect from the RCA coaxial SP/DIF port on the SB card, to the yellow 3.5mm jack on the 3-way lead from the ADA995. I haven't found anything to say whether the SP/DIF is carried on the tip or the sleeve of the yellow jack, but I'd guess the tip is most logical. I don't know what your chances are of finding such an adaptor, you might need to get one made by an electronics place, or solder one up for yourself if you can do that.
Edited by Platypus, 02 November 2010 - 10:59 PM.