I have a GA-Z87-HD3. I am trying to hook up a 5.1 receiver to it. I see an option for Realtek Digital Output as a playback device. I am lost as to where or what I would plug in for that option to put out sound. I have the standard 6 headphone jacks in the back but no other plug none of those would output 5.1. I don't see an orange audio "RCA" like jack, no hdmi other then from the on board video, and no optical jack. At the moment I am running it from my video card to the receiver then to the monitor, this only enables stereo or 2 / 2.1 not true 5.1. Just wondering what exactly it thinks the Realtek Digital Output is.