Upgraded amp for B&W 802d3

I would try Pass Labs. 

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.