Rotel RB1582 mk2 vs Emotiva XPA2 gen3

Agreed. For those 804 D3 you gotta upgrade from a stock Emotiva XPA2 amp to at least something like the Rotel RB-1582 Mk2 or the RB-1590 or the RA-1592 stereo integrated amp at the very least. Rotel & B&W have good synergy together.

But not only the power amp that will be a determining factor in sound quality or audio performance. Your upstream electronics play major roles especially your front end source components whether digital or analog front end source components. Cables, listening room and speaker placements also have major impact. 

Having heard the RB-1582 mk2 for many months in two different rooms in my space, I don’t feel like they can really make the 804D3 shine. There are plenty of amazing used amps in this price range. It’s be helpful to understand how much you’re willing to spend and other constraints. Size, heat, willingness to try tubes, music you listen to. Etc. 

I ended up upgrading everything including all components, speaker cable, interconnects, power cables, power conditioner, and dedicated 20 amp outlets along with hours of positioning the 804s. All was worth it. Take it one step at a time and those 804s will shine. 

@zzkzl 

What is your preamp and what is your front end source component(s)? 
I would say that sell your preamp and digital front end source component if you already have them and buy a Naim Uniti Nova. The Naim Uniti Nova is an all-in-one single box solution. It is a streamer/DAC/integrated amp all in a single chassis. Got built-in Tidal music streaming app & Spotify Connect and is WiFi equipped but you can also use Ethernet cable. It is a very sweet musical sounding unit and will sound really good on your B&W 804 D3. Naim electronics usually pair well with B&W speakers. The Naim Uniti Nova currently retails for $7500 new. Highly recommended! 

I had the Nova paired with the B&W 805 D3 in my bedroom setup before and they sounded fabulous together.