Hi— I am demoing a Luxman 509x right now, and hooked it up for the first time last night (with Rega P10 > Apheta 3 > Gold Note PH-10 and B&W CM9 speakers). On first run, the stereo playback of my 1st UK copy of "Wish You Were Here"—with the Line Straight setting which bypasses any tone control—was staggering. Huge soundstage, crazy dynamics—jaw dropping stuff. When I then played my all-but-pristine OG mono copy of "A Love Supreme" with the Mono setting, I didn't get the same results. I felt like the staging and imaging were compromised—like the instruments were on top of each other without enough space in the presentation and without the clarity of imaging. The overall authority just wasn't the same. I felt that the presentation wasn't even as good as my mediocre Integra home theatre amp I had just disconnected. Anyone have any experience with mono playback on a Luxman or have any thoughts on why I might have had this experience?