Separates suggestions appreciated

I don't quite understand what you mean by 4K, is that what you will have to spend? Awhile back, I needed to replace my Adcom five channel amp,  and wound up buying and building (eventually), three Class D Audio kits that have done an excellent job for me. Just recently, I had to replace my old Primare preamp-processor, and I bought a nice, used, Arcam AV9 unit for a bit over $700 to replace it.

Back to the amps, for my main speakers, I made one amp using an upgraded power supply, feeding two bridged-to-mono modules, for 5oo Wpc. I am very happy with this arrangement, it sounds excellent, but I have a separate all tube system I switch to when I want to, but for a large portion of my listening, this low-cost solution does a great job.

If you're not too worried about resale, or if you wish to have High End type gear, these amps sound incredible, especially for the price, but may not be for you if you have asperations for uber high-end gear.

Just my two cents. Regards,
Dan

The Marantz SR5013 is an AVR not a pre/pro but yes you could use it as a pre/pro with an outboard amp.  My understanding is that the Monoprice Monolith amps have a very high performance/price ratio and considering they are built by ATI, should provide years of trouble free enjoyment.

Bill 

+1 for islandmandan

     A class D amp is the way to go if you want hi-end performance at a reasonable price.  Owners of mega-buck power amps rarely have positive opinions of them, however, because it's just too embarrassing how similar good class D amps sound to their amps for so much less money.

     You can buy complete amps or build one in kit form if you're handy and want to save even more money.  They offer extremely low distortion and background noise levels combined with very good power levels and dynamic range performance.  They also offer exceptionally good bass response and overall a very accurate and neutral presentation from top to bottom, very much like the audio ideal of 'a straight wire with gain' that doesn't add or subtract anything from the inputted signal.

     If you prefer a warmer sound signature, you can always utilize a tubed preamp to alter or flavor the overall sound to your preference.  Since good class D amps are so neutral, all changes to the quality of preceding gear are more easily discerned including preamp type, preamp tubes, source components, recordings and even changes to interconnect cables and power chords.
     Based on my experience formerly using good quality class AB amps (Adcom, McCormack and Aragon) in my combo music and ht system and now utilizing 2 stereo class D amps (a ClassD Audio SDA-440-CS for rear surrounds, an Emerald Physics EP-100.2SE in bridged mode for the center) and a pair of D-Sonic M3-600-M mono-blocks for my main speakers, I know the class D amps outperform my former amps in all the categories I  care about.   
     Class D amps not only perform better and cost less than class AB amps in general, they're also smaller, lighter, cooler running and use a fraction of the electricity compared to class AB amps.  In my opinion, there's really no need to consider a class AB amp unless you have the budget for the top brands like Pass.
     The benefit of going to separates are typically better performance and more flexibility in upgrading.


Tim

Wow lots of info, thanks much.  I'd not even thought of islandmandan's approach.  Oh to answer his questions 4k as in TV (drives me to do something) and like to keep under 2500 USD for the amp(s).
Appreciate it.