Once I did so, I was able to confirm the impression that had been forming during the setup period. The sonic performance is perhaps best described as "transparent." Three years ago, I remarked on how good the 950 was with CD's, but the 990 is a somewhat different case – more refined, perhaps, and even clearer. The soundstage is better, as is the imaging, most noticeably with CD playback in stereo. The noise floor on the 990 is lower than any other piece of gear I've worked with. Several times I found myself standing in front of the entertainment center while running a wire or swapping between the stock remote and my MX-500, almost directly up against the center channel or one of the main speakers, and with the 990 on an inactive input (not muted, but with everything on and no signal for the unit to reproduce) the speakers were dead quiet. There was no noise, no hiss or hum or buzz, nothing to call attention to the 990 at all. You could put your ear to the grille cloth and hear nothing. It was almost eerie at times.