Yetis, when dealing with computer audio, it might be more difficult (or impossible) to simply slave the machine to a DAC with master clock. The reason is that the Master Clock needs to give the frequency for the data to follow, and computer audio is often associated with many different sampling rates. I won't get too technical here, but the answer is that the clock link is not absolutely necessary at all, only if you are in it for the quality. But if you really wanted quality, you'd think twice about including PLL's to derive the sampling rates, which is what computer audio does, since a separate clock would otherwise be needed for every sampling rate, and that costs money to build. I am speaking from an engineering perspective here. From a user perspective, I would not get into it, because you have to drill holes in the sooloos and experiment and it may or may not work, something might break, and then sooloos will not give you any money for trying to raise the quality of their device.
All this wonderful user interface make-up is nice stuff. But still it make you feel you are on Amazon looking for a CD.