I have a FLAC player with Line out,mini usb and 3.5mm aux ports.I want to play this through my Onokyo Home Cinema System which has HDMI,Digital/optical ports a normal red/white line in.
I would bet a dollar that Mini USB is for powering / charging only.
So, your connection would be "Player Line Out" -> stereo cable -> "Receiver Audio In". On the receiver, that Audio In could be labeled "CD In", "Tape In" etc.