What is purpose of a cd transport?


Some people say that a certain cd transport is "good." How can one cd transport be "better" than another?
Isn't their job just to hold/play the disc?
samuellaudio
Does the apple airport express provide a quick enough & accurate digital signal for DAC purposes?
In my system, it certainly sounds like it does.

For a published, numbers-based opinion, go to Stereophile's website and search on Airport Express for a 2005 John Atkinson commentary. He says the AX output is bit-by-bit identical to an original WAV file. (Note that this also means Apple Lossless compression is bit-perfect, since iTunes streams everything to AX in AL compressed format.)
Crudo20,

I have no doubt that the digital output from the Airport Express will be perfectly faithful to the digital data that it receives from a PC. The analog output, however, is unlikely to be as top notch as you might get with an expensive DAC or CD player, but probably good enough for most needs; like feeding various built in speaker zones in a "smart" home (I use my Airport Express to feed a Russound Amp in my utility/boiler room, which feeds five separate house zones).
Crudo2,

Here is a link about the airport express

http://stereophile.com/digitalprocessors/505apple/

...perfect performance with 16 bit 44.1 Khz digital out (standard CD digital)
Thanks for the link Shadorne. I think I'm going to go for that and then find a DAC to run it through. I keep reading about the death of CD and it seems that I'll be content with digital for convienience and analogue for quality. Now I just need to find a reasonable DAC - it seems that audio mirror da-1 isn't listed for sale anymore.
I love this post. In the beginning there is an abundance of reasoning and theory as to how a transport will affect the output sound...and then along comes someone with actual information (Shadorne) and the thread ends abruptly!

I do love the rich language that people use to describe the vague sonic minutiae that they hear from switching components, and I also love when people hear those differences when it may be physically impossible to do so! It's not a bad thing, because if our perceived listening is a combination of physical vibrations as well as psychological influences, then one can be affected without the other and our perceived listening will still improve. And anything that improves perceived listening is a good thing whether it's a glass of wine, an upgraded component, or a nice breeze.

Listening is influenced by so many things, and if getting an expensive transport lets me perceive my music in a more enjoyable way, then in effect that transport actually made my music sound better (to me)!