If you do, try using that instead of optical. My understanding of optical is 2 channels only for lpcm. However, you could get surround with bitstream, which should pass through optical but the quality may not be as good as lpcm. but maybe give that a try also.
I can't seem to figure this out. I have an apple tv hooked up to my home theater receiver and can't seem to get 5.1 audio from videos encoded with aac audio. i've tried multiple setting changes on the apple tv with no luck. I have a pretty old receiver so I'm thinking that the receiver does not simply support aac but when I tried a newer pioneer receiver that supposedly supports aac through HDMI, still no 5.1 audio. currently i have the audio out through optical cables and yes the settings are correct on the receiver to receive from the optical connection as I do get 2.0 sound.