Couple of other simple and relatively inexpensive solutions. I have a similar problem with my desk/computer removed from my stereo rack. My DAC is a Cambridge Audio DAC plus. I tried Chromecast audio which sells for $35 and would plug in to your DAC thru a mini-Toslink to Toslink (optical) cable ($15). If you set up Chrome browser on your Mac or any other device it will "cast" music to the Chromecast audio and then to the DAC. I did seem to have some reception issues with the Chromecast audio intermittently and was very unhappy that it did not support airplay. So I switched to an Airport Express ($99) using the same cable connection and am able to stream my music from iTunes. I also have quite a bit of high res music on my Mac and I understand that if I install J-River software I will be able to stream that to my DAC thru the Airport although I have not yet tried. BTW I also have set up a Mac mini to connect directly to my DAC via USB as theoretically this should be better quality sound. (I use remote software from my iPAD and placed the mini on my stereo rack next to the DAC) With the mini next to the DAC and a direct USM connection I was able to play my high res files using VOX. So there may be some cheap methods for experimentation!
Joe
Joe