The Beo-Mac section of the forum very well explains how to get unaltered digital signal out of a Mac playing iTunes (directly from the Mac or via the Airport Express optical digital out) by by-passing the internal audio handling of the Mac (as any internal sound processor will alter the sound). The unaltered digital signal is then fed to an external DAC for uncompromised quality.

Could someone explain how to do the same result with a PC playing iTunes via Airport Express: how does one by-pass the PC audio handling and get unaltered digital signal from the Airport Express?

Thanks, js

Pretty simple in that it works almost exactly the same on either a PC or Mac. In fact some of the USB DACs work on both platforms. Another approach would be to add one of the audiophile soundcards from ASUS, Creative, etc. for roughly $200 you get a audiophile DAC, which can be customized, along with the superior performance of a card that plugs right into the motherboard. Personally, I don't think I would want to trust the analog outputs of a USB DAC to drive an expensive high powered audio system. I hate to think what might happen if the cable were accidently disconnected while the system was in use, perhaps nothing, but I prefer not to find out.