Believe it or not but I have experienced that motherboards can also sound different from each other...

btw: Foobar is the leanest sounding app that I know of, which might explain to an extent why the Oppo sounded fuller.

Rowland Model6/BPS6, Rowland Coherence II, Levinson 390S and 37, AudioAanZee Reference Flow music server, Rowland Aeris DAC, Rowland Cadence phono stage, Pass Labs Xono phono stage, Yamaha PX-2 and Thorens TD 160MKII, Transparent Ultra and Reference cables, Apogee Diva magnetostatics (refurbished).