airport express questions


The airport express is equipped with a mini-jack that is a combo: analog and digital toslink. Monster sells a variety pack of cables to go with the unit, including a mini-to-full toslink cable, and a mini-to-RCA cable.
How can I be sure that I am streaming digital audio with airtunes? Is there a box in some dialogue window that I need to check? For analog audio, which I don't want, does the airport express have a crappy internal DAC, or would the laptop be wirelessly streaming analog from its own crappy internal DAC? Laptop is a 5 year old Sony Vaio, windows XP. Thanks.
realremo
When you hookup to the out via a toslink it sends the pure digital signal to whatever you hook the toslink to, such as a DAC. If you use 1/8" to rca from the same jack the airports internal DAC does the conversion and sends out an analog signal. The airports internal DAC is not that great, a budget DAC will work wonders. Pickup a mini toslink cable from monoprice.com and run it into a DAC or processor with a digital input so that the processor can do the conversion. Search on stereophile.com for their article on using the airport express in a hifi system, very informative.
Better yet, for much improved sound IME, get an inexpensive jitter device like a Monarchy DIP...run the mini-Toslink into the Monarchy (or other device), then use an alternate connection from the Monarchy to your DAC. If your DAC already has excellent de-jitter capabilities then this route may not be necessary.
Thanks guys - I was thinking about the MF V-DAC - which I don't think has good jitter reduction. I can always add a re-clocker later...I have a birthday coming up and I want to get into PC audio. DAC would be connected to an ancient Yami receiver, running B&W 685s and a HSU VTF-1 sub (connected via speaker terminals).
BUT I would need a toslink cable with a mini-plug on one end and a full size plug on the other. I found one on monoprice.com, thanks, these look good. Any idea where I can find a high end one? I think I saw "van Den Hul" or some such makes one?