pc vs blu ray player sound quality

I am using my pc for both music and movies.  However, ripping blu rays to my hard drive is onerous and playing blu ray discs on a computer is frustrating.  I'm a using an ifi idsd dac and tried a sony stand alone blu ray player connected to the dac via coax.  However, an A/B comparison revealed the sound quality of the stand alone player connected via coax to the idsd was highly inferior to the sound quality of the computer playing the same blu ray disc ripped to the hard drive connected to the idsd via usb.  Any ideas what would account for this difference? The convenience of the stand alone player is great but the computer's sound quality blew it out of the water, which does not make any sense to me because the pcm streams should be identical.  
Asynchronous USB.

Means the data flow is controlled by the DAC, and the DAC no longer has to put up with garbage data feeds.
Thank you, Erik.  So is it safe to say that the audio for movies will always be better from a computer vs a blu ray player due to the usb connection? Also, I am looking to upgrade my dac and a  friend whose opinion I greatly respect suggested that I look for a used Monarchy audio M24, but I would have to use a usb to spdif converter with it.  Are you familiar with this dac and do you have any thoughts/other recommendations in this regard?