Airport Express wav file vs CD played thru iTunes

I think you need to use lossless/ACC files to get the same quality or close too as a CD. WAV, MP3's are compressed, look at the file size btw the two.

We have been ripping CD at lossless and yes they take up a huge amount of space but in comparing them to a CD the sound is almost the same (qualifying a bit)

WAV files are uncompressed and should be of the same quality as a CD, no?

I'm streaming wirelessly from iTunes on an iMac G5 through an Airport Express connected by glass toslink to a Benchmark DAC1 and then to my amplifier.

WAV files, which, as Arm said, are uncompressed, Apple Lossless files and AIFF files, which are what you find on CD's, are indistinguishable from each other. MP3 and other compressed formats don't sound as good, though MP3's at the higher bit rates aren't bad.

The one thing you have indicated that could be involved with the sound quality is when you indicate:

"is the wav file encoder for iTunes the issue?"

My question to this is are you ripping your CD to your computer using a WAV lossless file then importing this file into iTunes? While I am no expert on iTunes (don't much care for it personally), I thought when a file was converted and brought into iTunes it became an MP4 (which is compressed).

Perhaps I am off base on this, but I would check and confirm that you are bringing the lossless WAV file into iTunes (if there is any conversion, which I thought there was) using an Applelossless codec versus the standard MP4.

Also, I suspect that the internal DAC is part of the issue, but it sounds like you are already planning on doing something about this.