Even if you do a comparison between two DACs--one with a huge power supply and one without, how do you attribute any difference in sound, if there is any, to the power supplies when everything else is different? The entire design and implementation matters.
It really comes down to the ASR measurement-is-everything approach vs. subjective listening. I can think of nothing better for showing how little measurement really tells one about a DAC than going to an Audio Note dealer and listening to something like a DAC 5 (or any of their lesser DACs). The Audio Note DACs measure so poorly, deliver waveforms that are almost totally unrecognizable from sine waves, that they should not be able to produce any music at all. Do the audition and tell me if that is what you hear.