Best multi channel amp and processor good for 2 channel listening.

wow, one of the best discussions I've read in a long time on any forum. Civil, very informative and lots of expertise/ experience.      

I'm using a "vintage" Marantz Sr6003 (soon to be replaced by a SR8012 or 8805 lol  thinking, thinking ) in my system as a preamp to the front three, and bi-amping off of a six channel Krell S1500. I've tried Bryston, Sunfire (rebuilt 5 x200), Carver and Parasound amps before settling on the Krell. The SR powers the sides and rear speakers in a 7.2 configuration. Using KEF Reference 5s (bought new/used for a great price )  and 4C for the fronts, Q900 sides (use to be the fronts) and Q800d for rear (which must be rewired to work correctly BTW) .System is used 40% for music. Truly sounds amazing IMHO and to all of those of all that have heard it. And much better than systems I've heard that have cost more. The S1500 never runs out of steam and suits my tastes for speed, articulation, and clarity just perfectly. That being said, the S1500 is very honest in that it presents everything upstream as they are... it doesn't hide weak links of which I still have a few lol But I'm working on it! I have a second surround system 7.1 in my mancave (75% music) powered by a Marantz 6007 and the Sunfire 5 x 200.The Marantz have been very dependable, are very musical,have great voicing for TV / movies, offer excellent switching, easy menus but are neither warm sounding nor clinical. 

not a hint of brightness out of mine, but it is revealing no doubt. Using it to bi amp really works remarkably well for both the amp and the Reference 5s. Just a great synergy. Good luck with the sale. Shouldn't take long at all. 

the finger snaps on Patty Barbers version of Ode to Billy Joe is a real differentiator between amps. Those seem incredibly difficult to get just right. I also listen to cymbal strikes and decay as well as the same on piano. Ahmad Jamal's Blue Moon is excellent for this. Bob Wasserman Duets is another go to for voicing and differentiating between amps and sources. 

following the latest line of discussion regarding HT for music. The center speaker itself makes significantly more of a difference than any other component in getting voices absolutely correct. One of the primary reasons I selected KEF Reference 5 speakers was the matching 4C center. It's the only center I've heard, and I've auditioned a bunch, that lets voices sound as perfectly normal as the recorded source does.  I find that using a preamp that retains memory for music settings, as opposed to only HT setting, gets me where I want to be whether it is music in stereo or multichannel.   Yes Melody Gardot and Patty Barber are both excellent choices for verifying both imaging ( sometimes they are next to the piano not centered lol) and perfect voicing. I also find that sax and trumpet are very useful (both mono recordings and stereo) since they seem to encompass both mids and highs, a test of both the drivers and the crossovers.I've not found that the amplifiers play as much of a roll as do the speaker(s) followed by the sources once you're at the level of equipment you are at.