I know it is an old message that I am responding to but here is the answer.
Since I recently introduced a clock to my system that forced me to do lot of research using which I am writing my answer.
In order to make it work, both DAC and source must use the same clock so, had dCS put a super expensive clock in their DACs, it would not be used unless the source uses the same quality of clock. So, get a source and DAC with clock input and clock them with a high quality clock and you will hear the magic.