sajunky
Headphoneus Supremus
It means Fred is right. Any attempt to correct theoretical 3dB drop at 20kHz destroys phase coherency of treble or a timing, depends what filter is used.And so far, whatever is happening in Os0 mode I'm really liking it! Think it's my favorite setting so far. NOS mode sounds good but my initial impressions are that it has a "gritty" aspect to the treble. Not sure how or why I'm hearing that or if I'm imagining it lol. But Os0 smooths things out nicely, and I also think I'm hearing a deeper soundstage with more defined imaging.
A mode that sounds more silmilar to your R2R-11 is a real NOS. That's for sure. I only have R2R-11, can't compare.