Guys,
it all depends what is understood by the term 'clock accuracy'.
For example rubidium clocks have very poor short term stability, they jitter by design. This makes them totally unsuitable for a short term time base reference. Their big usage is due to their long term stability where the time has to be correct after a long time without synchronization (eg military applications). The long term frequency stability, the clock 'accuracy' is defined in ppm (part per million). The highest clock accuracy is not required for hifi applications.
An OCXO (or TCXO) has a better short term stability (phase noise) but is doesn't have the accuracy of the rubidium. .
As in hifi the real long term stability isn't important, the better clock source is a very high quality OCXO or a TCXO.
My point is that the absolute accuracy of the clock is not as important as other aspects of it (phase noise, voltage stability, jitter, etc).