CDP breaks and I move to computer-based...

Core Audio is part of the MAC OS. Kmixer is windows- two different animals.

In a MAC environment typically you would set core audio to 24 bit- set and forget and let itunes upsample everything which it does well. The other option is changing core audio based on what file is being played and matching them so they are native. This requires stopping itunes, changing the setting in core audio to match whatever file is being played and then restarting itunes. All of this is done to avoid having core audio upsample or downsample which it does very poorly. iTunes ironically does it well.

24 bit files are not available in the itunes store, but itunes can play them. If you download a 24 bit file from a place like hdtracks.com it will come in FLAC- you then convert to WAV, ALAC, AIFF, any lossless codec that iTunes can handle. Unfortuantely iTunes cant do anything with FLAC so it needs to be converted with another piece of software.

As it turns out, 4est was right, something simple was wrong: The EQ option was active on iTunes, which imparted a subtle but noticeable effect on dynamics and overall presence. This is what I perceived as *lacking* in my original post.

I have a great iMac set up feeding a dcs purcell upsampler and a dcs delius dac. I had the Ayre C5xemp CD player - a very excellent digital front end with a cavernous sound stage.

The computer-based set up I have is better. However, it should be as it cost about twice as much. I doubt if I ever buy another CD player. The big thing I noticed is that the computer server simply makes your music so much more accessible, easier to burn CDs for the car/office, and I listen so much more to my system than before.

I would've never believed that listening through a computer would sound so dang good.......