I am confused about whether or not i can use a spdif cable to connect my computer to an older home theater-in- a-box system i own. My computer has an optical spdif output, and right next to it is what i beleive to be the non optical version of spdif. On my home theater their is a "digital in" port. Is this digital in port also a spdif port? My motherboard is a GA-MA790X-UD4P and my home thearter is a philips hts3450/37.