Spliting the signal is not going to make a 5.1, you will get stereo on 6 speakers. Check if your sound manager can setup to 5.1? If you can, then you'll need 3 mini jack to RCA cord to connect it to a surround amplifier input or to 5.1 speakers.
Thanks for the reply. Yes, the sound manager can handle 5.1.
Could you point me to a site that sells 3 mini jacks -> RCA please? I searched for such a cable before I posted here, but couldnt find it.
Really appreciate it!
I can't find any info on the STV surround sound but if it doesn't have a 5.1 channel discrete input you won't have anyplace to connect the output of your card to. If if has a digital input and your audio card will output SPDIF digital audio then go that way. If the STV doesn't have digital inputs then just use the front stereo outs from the audio card (set the output to 2 channel) and let the Dolby ProLogic processing in the STV create the surround.