From today's (free for the asking) Stereophile Newsletter by John Atkinson:
"Of much more significance ... to the high-end audio industry is Apple's Airport Express. Wes Phillips cryptically referred to this inexpensive WiFi hub in his "As We See It" essay in the forthcoming April issue of Stereophile: "When Apple introduced its Airport Express wireless multimedia link," Wes wrote, "it even included a digital port so that an audiophile—such as Stereophile's editor—could network his system, using the AE to feed his Mark Levinson No.30.6 outboard D/A converter. 'Sounds okay,' deadpans JA."
And yes, the AE did sound "okay." I was sufficiently impressed that I wrote a review of the piece for our May issue. I won't give the game away, but I will say that, in combination with iTunes running on a Mac or PC, an Airport Express feeding that high-end D/A processor that you never could decide sounded better than your one-box CD player is the easiest way of piping CD-quality music throughout an audiophile's home.
"CD quality"? Yes, the data appearing on the AE's digital output are identical to the data in the original file. While preparing my review, I compared a WAV music file with a duplicate that I had captured on my PC from the Airport Express's S/PDIF output. I used iTunes on my PowerBook, playing a version of the file encoded with Apple Lossless Compression, to feed data to the AE. Despite the lossless encoding, despite the 128-bit encryption I use in my home network, despite the transmission of the packetized data through the air, and despite the circuit in the AE having to reencode the data as an S/PDIF stream, the files were bit-for-bit identical.
Apple's Airport Express is most definitely not bs. And it costs only as much as three Golden Sound "Intelligent Chips."—John Atkinson"