24 Bit - how to stream?

Apologies if this is covered elsewhere, which it probably is, but how do I stream 24bit files from my Mac via AE to my DAC/Hifi?

Currently I use Max to convert them into iTunes but seem to remember that the AExpress can only handle 16 bit. So either way I'm not getting the full fat file.

Is there any way to do this with my current set-up?*

*

iMac
Chord DAC
Airport Express
Amp/Speakers etc