Ayre AX5 Twenty

plenty of online reviews out there

excellent piece

A rather expensive integrated considering it’s power output,    that has been rather well received by reviewers. It should be noted that original AX5 measurements suggest that it is not an ideal candidate for low impedance speakers. 

Here are measurements for the Ayre AX-5 Twenty. https://www.hifinews.com/content/ayre-ax-5-twenty-integrated-amplifier-lab-report

That’s plenty of power for all but a handful of speakers and preferences. Of course, it’s always best to listen in your own room/system whenever possible.

 I love mine: my best piece and my final amp.

For comparison sakes here are the measurements for the earlier model:

Ayre Acoustics AX-5 integrated amplifier Measurements | Stereophile.com

Notice that it's only able to produce 220 Watts into only 1 channel rather than the 500 Watts into 2 channels that a 125 Watt stereo amp that could ideally double down and double down.  And it's becoming unstable doing so into that 1 channel driven 2 Ohm load. 

The original AX-5 was a fine amp. The Twenty version sounds even better (it’s in my top 5 ever heard) while being much more tolerant of difficult speakers. Anyone looking at the AX-5 should either get the Twenty version or plan to have an original version upgraded at the factory.