This has nothing to do with bits. The bits arrive just fine. The problem is ground noise and pre-processing of the bits. Most media players do digital manipulatino of the signal to put it on the media bus, and then spit it out. Most also do some level manipulation, including digital volume control, which rob you of resolution. As numbers are multiplied (which is how volume control is achieved) there are remainders nad truncation's. You can very esily get down into 10-12 bits effective resolution.
It matters not if its a $10,000 gaming PC or a 10 year old core duo. Same problem exists.