My Sky HD box is connected to Yamaha receiver via HDMI as well as optical cable. I'm not getting 5.1 audio.
I checked Sky help page:
In the 2nd point (check the audio output), the picture shows options of "Digital audio output - optical" & "Digital audio output - HDMI", but I'm just getting the option of "Digital audio output".
I've confirmed that the connections are fine. I'm still only getting stereo sound via HDMI. When I disconnect the HDMI cable while a Sky HD movie is on, there is a distinct improvement in audio quality as then the only connection is optical. Obviously, there is no picture when HDMI cable is disconnected. This proves that I'm getting audio via HDMI.
How do I get audio through optical cable?