02-14-12: AudiooracleTrue, obviously, to some extent. However, it should be kept in mind that the ability of a system to resolve musical information, and its ability to resolve differences between components, while obviously having some degree of correlation, are two different things.
First of all it depends on the resolution of the system and the acuity of your ears!
For instance, a digital transport that provides a highly jitter-laden signal to the DAC will be more resolving of differences between DACs than a transport that provides a signal having minimal jitter. A transport having an inaccurate output impedance will be more resolving of differences between DACs than one having an accurate output impedance, everything else being equal. A S/PDIF digital interconnect cable that provides poor shielding against emi/rfi pickup, or that has high shield resistance that can contribute to ground loop issues, or that has poorly controlled impedance characteristics, will be more resolving of differences between DAC's than a better cable. A preamp having low input impedance will be more resolving of differences between DAC's than one having higher input impedance, everything else being equal. A comparison between a given group of DAC's may turn out completely differently depending on the happenstances of the risetimes and falltimes of the output signal of the transport, and the propagation velocity of the interconnect cable. Etc., etc. A great many other comparable examples could be cited.
My point being that while it is easy (and very common) to blame the quality of a system when there is a reported inability to perceive differences, that is not necessarily what is going on. And in fact an inverse correlation may often exist between the ability of a system to resolve musical information, and its ability to resolve differences between components, cables, tweaks, etc.
Regards,
-- Al