Having now owned the Mach2 for a couple of weeks, I have some basic observations.
First, a learning curve existed for me, and I consider myself reasonably savvy when it comes to Mac computers. There were a few roadblocks along the way involving "headless" set-up with my home network that I solved on my own.
Second, careful attention must be paid to the sample rates configured on the Mac, and in the playback software. Make certain the rates match the capability of your DAC and of your USB>spdif converter (if applicable).
Third, the MacMini does not make noise. However, the external hard drive on which the music files are stored does quietly whir, which can be heard a few feet away during quiet music passages.
Fourth, the computer and/or hard drive can vibrate a good deal at times; particularly during ripping of CDs. The vibrations travel through my rack and into my components despite the fact the components are are placed on various vibration control footers (Stillpoints and Synergistic Research MiGs). I placed 3/8" sorbothane pucks under the MacMini and hard drive and mass loaded them with brass weights. This has reduced the transfer of vibration to the rack. I would not recommend hard footers. They do nothing to stop the transfer of vibration to the rack.
