Apple TV 2nd Gen. 5.1 audio output to a 2 ch DAC

I just acquired a new ATV, and it sounds wonderful w/ AirPlay music; quite a lot better than my Airport Express that it replaced; more stable lock & w/ discernably less jitter.

But I am reluctant to purchase content on iTunes such as a movie w/ 5.1 DD audio.

I am feeding the device's Toslink optical audio output to my PS Audio DL3 DAC and the HDMI cable to my projector.

Since the DAC cannot/will not decode DD 5.1, what can I expect to hear, if anything from a 5.1 stream?

Has anyone tried it?

The settings for Dolby Digital audio are: Auto, On, Off. No option to stream down sample to 2 channel PCM/LPCM.

Somewhere I read that the 5.1 stream is not true DD but actually a 6 channel AAC stream. But the specs on Apple TV are Dolby Digital Pass Through on the Toslink.

I do get audio when browsing and playing movie trailers and such, but don't know if that is 5.1 audio in most cases.

BTW, I already called Apple as well as submitted feedback on their website. Their technical support did not yet have an answer.

I figured I would buy an inexpensive 5.1 movie and try it, but curious to know if anyone here has already attempted.

Thank you in advance.
-E