Home theater model is Sony BDV-E6100, the GPU of the PC is Evga GTX780ti Dual Classified and the mobo is Asus Maximus VII Hero. I also have sound card which is Asus Xonar DX.
Looking at the manual, I would connect pc to tv via HDMI, and use the motherboards optical S/PDIF out to connect to Sony and set that on the pc as audio out.
Looking at the manual, I would connect pc to tv via HDMI, and use the motherboards optical S/PDIF out to connect to Sony and set that on the pc as audio out.