I think Inscrutable put it in perspective best, above here. And IF you were going to use most any sort of AV receiver in the context of some semblance of a "hi-end system", using it as the pre/pro - not the amp sections - is your best bet for quality sound. (if you can get a good EQ into the mix - audyssey, etc - you're ahead of the game even futher)
What you'll find is that the smaller more essoteric receiver builders are going to offer you more refinement overall, with either direct analog or digital connection, for musicality and overall sonic refinement, likely.
I do find that, with typical mass manufactured receivers built over seas, I like the clarity and "relative" neutrality from the likes of Yamaha, Harman kardon receivers, Pioneers and Denon's bettter pieces, for their pre-amp sections.
Note that you're still are not going to get ultra high end refinement from most all of these as pre-amp's either, considering all connection modes. But, for the most parit, if you can get lots of detail, clarity, good dynamics, and a nice open sound, it's still pretty darn good with music, and excellent with movies, all-in-all.
With most typical, even higher end AV atand-alone pre/pro's, You will probably get closer to higher end refinement going the likes of Macitosh, to Krell, to Theta, to Meridian, Anthem, whatever . Yet, you're still not likely going to realize the level of refinement as what the best analog preamp's offer, using outboard sources for processing and such...all things equal. However, you're getting much much better refinement using these very same hi-end offerings in that role than typical AV receivers, used in any capacity, true!
So a good options here would be to use one of the mass market av recievers with which offer a good clear, detailed, dynamic sound for their preamp sections - that's opt #1. Next step up would be a better, more essoteric av receiver from some of the smaller companies, used as a pre/pro. Above that, you gotta escape to dedicated separates AV pre's. And beyond that, to maximize potential from high end 2 channel sources, you're probabaly going to have to loop an expensive 2 channel analog preamp into the system, or go stand-alone. - and consider higher end outboard EQ into the system to tweak the sound.
I personally go with a mid level HK AVR354 as a standalone pre/pro (has an EQ) out to a Parasound HCA1205a for my system currently. Actually, the amps are stronger and much better sounding than most at this price range, built into the HK. So I use the receiver by itself for small setups. Still, the receiver, on it's own, can't match the current delivery of the Parasound, with a load, for sure.
