I've got an Air Enabler on the way, as well as an external USB DAC with "2VRMS" outputs. My goal is to eliminate the intermittent connection cut-outs I still get once in a while with the AEX, and to provide the MS-8 with a stronger input signal. The DAC was recommended to me on another forum. I'll report back once it's installed.
DAC:
http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1