usb, spdif, or usb to spdif converter

Many thanks and hope you all had a wonderful Thanksgiving.  I am running a windows 7 desktop computer (a 12 year old gateway) usb output to an idsd micro dac for both music and blu ray movies.  I would rather use a stand alone player.  However, when I compared the computer sound (usb to the usb input of the dac) to the player's sound (coax to the same dac - using a newer sony blu ray player) the computer's sound was MUCH better in every way.  Any thoughts on getting equivalent sound via coax from a player would be appreciated.   

Thank you. After reading the last 2 posts my gut tells me that my computer is a better transport than the sony BR player. Also I am playing rips from the computer's hard drive so that may partially explain the difference.  I power the idsd dac from its battery, not the usb cable, and it does sound better that way.  However, I have heard many times, on this forum and others, that the usb interface should never be inside the dac - hence the reason for my question regarding the usb to spdif converter. My dac is around 7 years old and I'm due for an upgrade - any recommendations new or used up to 1,000 that would best the idsd? One that was recomended was a used monarchy audio M24 but they are hard to come by.       

many thanks - actually I do find ripping too complex and cumbersome - the only reason I am doing it is because the computer sounds so much better than the sony br player -  curious - what is the other (complex) alternative?