Autoformer vs Speaker impedance Curve

...such as?

With this kind of impedance and phase angle load graph,
https://www.stereophile.com/images/616BW802fig1.jpg

I would look at good quality amps with big power supplies (that means heavy), that can "almost" double their wattage from 8 to 4 to 2 ohms, this is usually reserved for amps with BJT (bi-polar) output transistors.
EG: Krell, Gryphon, D'Agostino, Parasound Halo JC1's, and many others 

The 802 D3's are efficient, at tested 91db, so a even 100w amp at 8ohms is fine, so long as it "almost" doubles to 4ohms (200w) and 2ohms (400w)  

Cheers George 

Thanks for the suggestions George. I  probably shouldn’t have take this thread off topic by asking for suggestions. My bad. There are plenty of threads on that topic.  But...

I’m currently running a CA-2300 with my 802D3s (both bought used) and am very  satisfied with the combination. I will say, on very quiet passages, I can hear the air movement from the fan. This has pushed me away from the CA-M600 that was suggested.  But, the upgrade bug has hit.

With the MC611 out, there are lot of used MC601s on the market.

I’ve run the 802D3s with a very nice tube amp, 75 wpc Kt88. Sounds good, but a little loose and bloated in the bass with a very very slight glare in the upper mids. Mathematically, and to my ear, tubes and 802D3 are not the best match.  (Still on the hunt for speakers for my tube rig)

My my concern is  that  Autoformers may have a touch of that (obviously nowhere near as much as tubes...especially with 600 SS wpc!) without the magic of tubes.   

Just to get a feel for the Mac “sound” I listened to a MC452 with 802D3s in a poorly set up big box store. (The 601s we’re hooked up to Maggie’s, and they didn’t seem inclined to move them...they knew I was “window shopping) Seemed warmer, yet slightly less detailed than my 2300. Overall, I preferred my CA-2300, way better staging and presence, but that is likely more to do with the room.  

Way off topic and rambling. Probably just keep the CA-2300. 

I can hear the air movement from the fan. This has pushed me away from the CA-M600 that was suggested. But, the upgrade bug has hit.

Seeing you have a thing for Classe, this is what i’d like to see on them, it will control them with an iron fist, and if you need colourations try different preamps, they all sound different.

Find a used Classé Omega power amplifier, no fans, this below from the test bench is what "current (wattage doubling)" is all about and wattage. Not that you need that much wattage, a 100 at 8ohms would do.
.
" The Classé Omega proved a powerhouse on these tests (fig.8), generating
506W into 8 ohms
985.4W into 4 ohms
1886W into 2 ohms
and an astonishing 3425W into 1 ohm!!!!!"

It’s RCA input at 129kohm is fine for all preamps .
But it’s XLR input is only 8.4kohm so the preamp need to be very low output impedance (solid state) if the xlr is used.


https://www.stereophile.com/solidpoweramps/97/index.html

Cheers George

Find a used Classé Omega power amplifier

Nice!  Don’t see any on the market and they are 20 years old.  Recap time. I’m terrible with a soldering iron, and sourcing all the caps…

This would be nice, if you could up the ante a bit more.
https://www.stereophile.com/content/mark-levinson-no534-power-amplifier

If??? if you look at Class-D, something I'm not warmed to yet. I did hear one that made me take notice once, and that was the Belcanto M600 monoblocks, these "could" do the 802 D3's justice.

Cheers George