Upgraded amp for B&W 802d3

I would try Pass Labs. 

I think the XD Krell Amps are fantastic

Soix, which Pass Labs amp?  The 600.8?  That one is a little above my pay grade 😀.  Maybe the 350.8 stereo amp?

I have a pair of 802D3. I do not know the size of your room, but they are surprising efficient if your amp can provide the needed current. You want current not power. I started with a Hegel H590 integrated that puts out 301watts into 8 ohms and  590watts into 4 ohms, I moved to a Luxman 590AXii which is 30 watts class A into 8ohms and it sounded much better and I sold the Hegel.

I am now using a Primaluna EVO 400 Power amp (70 watts in ultralinear) driven directly by my Chord Dave DAC and it is the best of those combinations, I have owned Krell 302 EVOs as well earlier this year (300w into 8 that doubles in 2) and they did not sound as good as my current setup.

You want current, not wattage, for example the bass from my 70 watt Primaluna tube amp is MUCH better , stronger and tighter than my Luxman Integrated, which you will see many videos on Youtube videos driving Magico S5s. The Luxman had much stronger bass than my Hegel H590 which had a 4000 damping factor. The Primaluna Evo 400 pairs very well with the 802D3 as it is very detailed and airy, with incredible separation between instruments and singers.

So with going with an amp with high current as opposed to watts, would this mean an amp with m high class A output?  

Yeah, at 91dB you don’t need a ton of watts, but impedance is below 4Ohms from the upper bass through the midrange and dips to 3Ohms in both the upper bass and mids (as per Stereophile measurements).  So an amp with a beefy power supply and that is comfortable driving that load is pretty much a requirement for these speakers, which is why I was thinking a Class-A amp.  Many Class A/B amps are also fine with this (i.e. Bryston), but I think the refined yet detailed treble and natural tonal properties of better Class-A amps would pair particularly well with a speaker like the 802 d3.  But that’s me. 

I mentioned Pass because they’re great amps and people are familiar with them, and specifically I was thinking of the XA60.8.  If it was me, I’d get a Clayton Audio S100 that’s also an exceptional Class-A amp but about $5000 cheaper and has a low-bias switch so you can leave it warmed up without heating the house or blowing up your electric bill.  There’s an Enjoy the Music review that gives an idea of the amp’s sound, and you can read other Clayton reviews as the sonic signature is fairly consistent throughout the line. 

Incidentally, I worked for Magnolia and heard your speakers with McIntosh and thought those amps made the 802s sound relatively dull and lifeless, which they obviously are not — just my opinion FWIW.  And I actually don’t think the d3 tweeters are all that hot (especially if your ears are below the tweeter’s axis) but rather very cleanly detailed, which I think pairs well with amps like Clayton and Pass.  Anyway, hope this helps in some way, and best of luck in your search. 

The impedance only goes down to 3. They are not super hard to drive but get an amp with a beefy power supply. For example some 100 watt amps weigh 70 pds, there's a reason, a big power supply, big output transformers or big toroidal transformer. My Luxman 590axii puts out 30 watts pure class A and goes to roughly 95 watts in class AB but my Primaluna EVO 400 has much tighter and deeper bass, it also is heavier than the Luxman which weighs 62 pds. That weight is not just rocks or a bigger heatsink.

Thanks everyone for sharing your vast knowledge.  I did not realize class A amps made so much difference.  I will look into all the amps suggested.

OP, I went the other way.  I have older B&W 801Series 3 speaker and I was driving them with VTL 300 Deluxe mono blocks.  I wanted to get away from tube amps.  I tried Classe CAM 350 mono block for 3 months. Really nice amps and a good friend loves them.  If you have a friend with High Powered Tube amps, give them a try.  Should take the edge off and with those sub's you have, you should have a warm presentation with deep solid bass.  Then again the MC611 with the C2700 pre would be sweet.

Check out AVM which is a superb German manufacturer.  They have a neutral to warmer sound signature.  Udo is an ex Burmester guy and that influenced him.  The Ovation 6.3 stereo and mono amps have SS input stage and MOSFET output stage.  The Ovation 8.3s have a tube input stage and the same MOSFET output stage.

the lowest power of these four is 200w and they start at $10K

They are brilliant amps with very revealing speakers like B&W.  You will see them at shows with Magico, Wilson, Kef, etc....

Pass is obvious.  Brilliant gear and you need to figure out how much power you need.  That is really a calculation based on listening habits and desired headroom.  
Burmester, Constellation and Boulder all have nice Stereo amps under $20K that would be brilliant with those speakers.  
Luxman and Accupase would also be good choices.  
If you want tubes, VTL will work but prices on amps well suited to driving those B&Ws will get vicious.  
Full disclosure, I am a US AVM dealer.  I have other brands available to me but am not affiliated with any of the other brands mentioned here.