I use a "HagUsb" USB-to-S/PDIF Converter. I use USB out of my Mac Mini, into the converter, then digital coaxial into my DAC. I also can use at toslink cable. It's designed for Mac. Both of the above methods will get your MacBook connected to your DAC then it's into you system.
http://www.hagtech.com/hagusb.html
http://store.apple.com/us/product/M9573LL/A
A computer server has many way to get to music. I watch music videos on Youtube, Internet radio with iTunes and insert concert DVD's into the Mac's drive and watch while it plays through my main rig. I can also rip all audio output to my hard drive. Lot of options.
http://www.hagtech.com/hagusb.html
http://store.apple.com/us/product/M9573LL/A
A computer server has many way to get to music. I watch music videos on Youtube, Internet radio with iTunes and insert concert DVD's into the Mac's drive and watch while it plays through my main rig. I can also rip all audio output to my hard drive. Lot of options.