PC Rules

Rather than comparing vinyl to a hard drive recording of that vinyl you actually may have compared the line stages of a solid state preamp to a solid state preamp running through a tube buffer stage and differences in turntable stands/supports. What you should have done was make recordings of the stock interface and then recordings of the upgraded interface and then compared.

I also have a problem with your declaration that one sounds better. A recording can only sound faithful to its original or not. If the recording doesn't sound like the original, then by definition there is distortion in the recording chain. For any number of reasons you make like the sound of those distortions better than the undistorted original, but you are listening to a distorted version.

The original recording is those "squigly" things on black vinyl. The quality of the components between those "squigly" things and your ear determine how good the sound is. Each time the signal goes from one stage to the next, a new signal is born; consequently, by the time it gets to your ear, it has been reborn many times.

isn't this really about the sonic signature of whatever DAC is being used? perhaps the OP simply prefers his DAC's sound over the 'un-digitized' version. when I make CDs of my LPs, there's a noticeable increase in the bass, and the amount of increase is different depending on whether I'm playing through my CDP or through a different CDP using a DAC.

So if your theory is correct you should be able to loop the recording through your PC and continuously improve the sound on each loop? This is a fantastic breakthrough that could be the sonic equivalent of perpetual motion. My hat is off to you sir!