For a start, is there any that can do this? Send a Dolby Digital signal to my 5.1 home theatre surround sound via opticle, that will work with games that have 5.1 output like CS:S and BF2? I think that the HDA Digital X-Mystique 7.1 does it, but slightly pricey (looking at one in the 'you know place'.) Can you confirm this will do it? Is it any good? Thanks, Trif.