I have an older amplifier, a Sony STR-DE897, that does not seem to be able to decode 5.1 optical output from my Apple TV. All I get is two channel PCM 44.1. Am I missing some setting somewhere or do I need to get a new amp if I want 5.1?

I read somewhere that the Apple TV outputs Dolby Digital AC3. Is this correct? Is this what I need to look for in a new amp?

That AVR is only 4 years old, it can handle DD 5.1 over optical just fine.

Have you done the Take 2 software update for the aTV?

What file are you trying to play? Audio or video? Make sure you're testing with something that you know has 5.1 and is in the proper format for the aTV, i.e. like a VIDEO_TS that you've run through Handbrake.

I have that same Sony AMP and it works fine with ATV. Just make sure you have the latest ATV software. Check your connections, ATV setup and make sure your using the correct settings in Handbrake.

As far as I know, only the PPV HD content for AppleTV includes 5.1 (not sure this even does, 5.1 content for ATV limited). Make sure your content is 5.1.

I was trying to test using a movie trailer but I guess I don't know if the trailer is 5.1. Anything else I can use to test that for sure is 5.1?

Yes, I have the latest update

Anything else I can use to test that for sure is 5.1?

Do you have a commercial dvd with a 5.1 soundtrack? Do you have Handbrake? If so, then rip and encode to the aTV preset retaining DD 5.1--it's really one of simplest things to do in the realm of Mac home theater.

Problem Solved! I just pulled the plug (and plugged back in). The startup sequence has surround sound, all I wanted to do was confirm it was working before I downloaded my first movie