Apple TV 3 sound problem

Hi everyone!

I’ve been experiencing problems with my new Apple TV 3. I’m using and older NAD amplifier that only has analog inputs (RCA) and therefore I have connected the optical audio cable (TOSLINK) to the Apple TV and then by a Digital Audio Converter (DAC) to my amplifiers RCA inputs. The Apple TV is connected to my TV trough HDMI. I use a MacBook pro 13” retina, iPad mini and iPhone 4.

So:

MacBook/iPad mini/iPhone 4 (wifi) ->

Audio: Apple TV 3 optical output -> DAC (TOSLINK to RCA) -> Amplifier
Video: Apple TV 3 HDMI output -> TV

What I want to accomplish is this:

1. I want to be able to watch the video content on my TV but have the sound coming out of my speakers that are connected to my amplifier.
2. I want to be able to use the Apple TV 3 to play music via Air play when the TV is turned off.

Problem:

1. Almost always (but strangely not always) both audio and video is going through the HDMI o the TV and sometimes I get no audio either through the TV nor the amplifier’s speakers, and on rare occasions, the sound goes via the TOSLINK cable to the amplifier (just like I want). How do I fix this?
2. It is basically the same problem when it comes to using the Apple TV as an Airport express and listen to music while the TV is off – sometimes I hear nothing at all (not even when I turn the TV on), and sometimes, when I turn the TV on, it turns out that the sound is sent to the TV through the HDMI cable instead of going through the TOSLINK cable to the amplifier. Only sometimes the sound comes through my speakers just like I want.

I have tried to turn Dolby Digital on/off as well as set the sound output (I think that that is what it’s called) to 16 bits/auto in the Apple TV settings. That helped once, or maybe twice, but more often than not the problems above occurs.

I would greatly appreciate any help! Thank you so much in advance!

Ps. I apologies for my rusty english

Regards,

Anders