I thought Apple TV was a wireless product accessing your computer and that was the problem. Anyway, I've heard its sound quality is not audiophile.
On the other hand, I have an audiophile friend who replaced his $3.5k Resolution Audio Opus 21 cdp w/ a Mac Mini, matching Iomega 1TB HD, and iPod touch (as a controller) and tube DAC. He is acheiving better sound in his high dollar system than the Opus 21 provided.