AAC or AppleLossless

I am beginning to import all my CD's to my Apple laptop and want to know which is the best format to use for highest possible sound quality. I have heard recommendations for both AppleLossless and AAC. Anyone know from experience if one is better than the other? Thank you,
I have 1,500 CD's ripped with Apple Lossless. They are stored on three external firewire drives hooked up to an Apple iBook, which runs over USB to an M-Audio Audiophile USB and then an Audio Research DAC5 w/jitter correction. I have an Airport Express for the bedroom system upstairs, and through iTunes sharing I'm also able to play them on any of the other three computers in our home. Digital bliss :)

Before transferring all my files, I did a lot of listening tests with friends over to try and tell the difference between wav, aiff, direct from cd, Apple Lossless, and other various jitter correcting and upconverting DAC's. Apple Lossless was a no-brainer storage format as none of us could hear a difference between any of these bit-accurate formats. Jitter correction seemed to have a massive effect on "pace, rhythm and timing", and the upsampling affected the soundstage and imaging.

W9tr, why should ASIO matter to you? There's going to be no additional sound quality vs. DirectSound and you're only doing two-channel (not multichannel) so what's the big deal?
The big deal is that with a PC based platform running XP, I can't get decent quality out of iTunes because, as a directsound/waveout device, it goes through kmixer.

ASIO matters only because it is one way to bypass kmixer. So there is a sound quality difference with ASIO.

Since you are running an Apple iBook, you don't have the problem.
The Chaintech 710 with the Evvy 24 chip is a good source for bit perfect output on a PC. Price is about 25.00. I am using this with Via's latest drivers to my Tri Vista 21 DAC. I am using foobar2k with kernel streaming. Kmixer has been bypassed with this setup. Cmedia also outputs 44.1khz on the 8738 based card. I think another important aspect is the last device to output the clock signal to the DAC. If it introduces jitter and you cannot control it, the sound is crap.
Understand, there are multiple ways of getting bit perfect from a PC, but iTunes is problematic.

As iTunes/QuickTime is a Directsound/Waveout device only, (so far as I can tell), kernel streaming and ASIO are not an option.

Do you know of a way to use either ASIO or Kernel Streaming with iTunes? That is the problem I'm trying to solve.

If you could test this I would be eternally grateful.


I've streamed DTS multi-channel files via iTunes to my Airport Express unit, and than from there into my reciever via the toslink output and the reciever has been able to decode and reproduce the sorround sound fine.

Perhaps and Airport Express unit?