There is so much contradictory information on this and other sites that I need to come back to this topic. Is it really possible to stream hirez music data via Airport Express? People report doing it, but have they ever checked what's really coming out of Airport's S/PDIF? The setting: I have a lot of hirez AIFFs (24/88.2 and 24/96) recorded from my vinyl and I want to stream them unaltered to the DA-converter of my music system that accepts TOSLINK optical inputs from Airport base station's TOSLINK output. The files reside on my intel iMac where I play the files either by Amadeus Pro or by Bias Peak Pro. Airfoil is set to "Pure Playback" for streaming the music to the Airport base station's S/PDIF-TOSLINK and the music plays nicely on my system. However, when I checked the digital format of the stream arriving at Airport base station's digital output, I discovered that the stream is in 16/22.05. This is not identical to the format of the original AIFF. My question is: at which point on the way from the original files to Airport's output are the files being converted from 24/96 to 16/22.05? (a) Is it the program (Amadeus Pro or by Bias Peak Pro) playing the files that does the conversion to 16/22.05? (b) Is it Airfoil (although it is set to "Pure Playback")? (c) Or is it at the Airport client's (i.e. my iMac's) conversion to the IEEE 802.11g protocol that sends only 16/22.05 formats? IEEE 802.11g has enough bandwidth to stream 5.1 DTS signals. So it should be able to handle stereo 24/96 signals. (d) or could it be somewhere else I didn't think of (e.g. in the Audio/MIDI setup)? If one of these is the reason for the conversion, how can this be remedied to really stream 24/96 coding? If there is no such remedy, then why would I need Airfoil instead of iTunes that does the same?