I used the coax out. Given all you want is straight passthru, it worked well. Note the GTXP will do 6.1 decoding, you need the proper driver and player for this though.

If all you want is the optical or coax out, you need not get the GTXP. I will say your price of 230 is pretty high (that is what I paid over a year ago). I see it discounted to around 130 these days.

mdl.