I did enjoy the piece of music, in fact.
Some double-checks:
- When you are comparing the two versions (44.1 and 48.0), you are listening to both being played back on the *empeg* itself, correct? The issue manifested itself only on the empeg, not when being played back on any other device such as a computer.
- What player firmware version were you running on the player when you did the comparison?
- The issue was audible throughout the entire track, but to me was most clearly audible when there was a single solo voice singing by itself (occurs at about the 18-second mark in the track you sent). It's a "fuzziness" to the sustatined vowel sounds, as if the voice were being put through a distortion pedal (but with the settings turned down so it's very slight). I was able to hear it most clearly by going back and forth between the two tracks and fast-forwarding directly to the 18-second mark each time.
My empeg was a Mark2 with the capacitor fix applied. However I believe this issue would have sounded the same regardless of whether the capacitor fix was there or not. This wasn't particularly high frequency distortion (not in the super-high range that the capacitor fix affects).
It occurs to me that I have some packed-away "backup" Rio Car units here that I bought recently. I could uncrate one and see if the issue is audible on one of them.