Wilson Alexia 2

Agree nothing beats listening. But to give what your listening to, deserves to have the best measurements to do the job properly, and get the very best out of the speakers yes?
Even a big Nad will work into them and sound fine, and if you didn't know any better you could very well say that's the amp for them.

So tot get a "base line of amps" that will do these great speakers justice, the test specs are the 1st most important to be considered, for the "base line of amps to listen to".
Otherwise you get some saying  things like Cary 805 monoblocks are a great amp get them!! 

Cheers George

George:
In my home, the only difference in bass response between the Dag Momentum S250 and the Audio Research amps was the quality of the bass

That will be the output impedance of the ARC being 0.7ohm and the D’Ago being 0.2ohm this is 3 x the damping factor in favor of the D’Ago, the Gryphon is 0.02ohm 10 x better again than the D’Ago, and with even more current available.
The bass of the Alexia which is at it’s worse .9ohm epdr.
That’s why they’re so hard to drive to their best in the bass.

All this is reflected in what the reviewer and tester found with the D’Ago

Overall, the Momentum’s sonic personality, its high-frequency transients somewhat more relaxed, its bass performance ever so slightly less muscular

The output impedance was moderately high for a solid-state design, at 0.21 ohm at 20Hz and 2kHz

And that was on the Wilson Alexandria XLF’s
https://www.stereophile.com/images/113Walexfig1.jpg way easier to drive than the Alexia’s in the bass https://www.stereophile.com/images/1213Walexfig01.jpg

Cheers George

Please no Mcintosh.

+1

The ARC Ref 160 monos, ARC power supplies are monsters that enable the amps to grab and slam the bottom end as well as anything I have heard to date.

With high output impedance of .7ohm of the Ref-160’s into the Alexia’s .9ohm epdr bass they may sound good.
But surely not against the D’Agostino Momentum S250, or even a Gryphon Antilleon in the bass with these Alexia’s.

Stereophile:
The Audio Research Reference 160M’s measured performance appears to be affected by the design team’s decision not to use a lot of loop negative feedback. It will offer relatively high levels of low-order harmonic distortion when the load impedance is less than the nominal output transformer tap.

Cheers George

Insanely good speaker

I heard this very pair https://www.soundstageaustralia.com/index.php/reviews/84-wilson-audio-specialties-alexia-series-2-loudspeakers 
at length over time with many different amps using the same Total Dac/Lightspeed  front end.
The only two amps out of all the ones we heard that extracted the very best from these extremely hard to drive speakers, was the Parasound Halo JC1's and the Gryphon Antillion Evo. With the Gryphon Antillion being the chosen one over the Parasound if money was no object. I dare say that the new Parasound JC1+ mono's will close the gap.

Cheers George