Well first off, this is a large and substantial unit. I had some space allocated on my flexy rack and thought it would sit on top of my RP-91 and accommodate some small switch boxes. Wrong. The 555 muscled its way in there forcing the RP-91 on top of it, leaving no room for the switch boxes. No problem as I’ll just adjust the shelving to give more room, but wow, this is a big unit with a solid build quality to it and I like the carousel. Setting up was a snap as I simply stole 6-analog connects from the RP-91 and powered it up. Went to the menu and selected speaker config (5 small w/sub) and selected a redbook CD to start. I tried Dylan’s Love & Theft , which sounded ok but not stellar. Checked my connections and moved on to the multi-channel SACD of Billy Joel:52nd St. OK, sit down, fasten seat belt and hang on, this thing rocked! It was so clear and bright with instruments stepping up into the soundstage from all over the place. His voice was primarily coming the center channel as I just tried to focus on cymbals, drum, horns, piano etc. Everything just came together like I’ve never heard before. How people call this gimmicky is beyond me. Next up was Blood, Sweat and Tears 2-channel SACD. If you are not familiar with this, it is basically (11 piece ?) jazz band with a horn section, drums, piano and David C Thomas lead singer. In other words, there’s a lot going on there. I was floored by it. The soundstage created by 2-channel SCAD blew me away. I could not believe the clarity of instruments I was able to pick out. I could not believe how similar the 2-channel soundstage (without a CC) is to the multi-channel soundstage of 52nd St. Folks, I also run DVD-A from the RP-91 and it is very nice. But, there is something going on with SACD that is not present with the DVD-A setup. I’ve never thought of my system as bright, but the clarity was quite different to me. OK, but I’ve got a problem with regular CD’s. First a little background on my system. I’m using a VSX-27 receiver with a mix of speakers: NHT CC w/super zero rears, Paradigm PS-10 sub, fronts are Snell model-J’s from the mid-80’s. All the speakers use polypropleyne cones so they are timber-matched. I used to listen to regular CD’s through a digital connection to the VSX-27 (using the 27’s dacs) but that also meant I was using the sub. I noticed that when playing a regular CD through the analog connections of the 555, the sub was not being used. I was getting tired and had to retire at that point, but I’m puzzled by it. Perhaps the Snell’s are not good enough to cover the entire range with out a sub? But I never thought so before I got into HT and didn't have one. Maybe I missed something in the setup?