The curious case of the NAD Hybrid Class D

Hi everyone,
I bought an NAD 3020 D for the bedroom a few years ago. It's about the size of a large paperback, about 30 W/channel, with digital and analog inputs. I didn't really listen much to it, I just read a reasonably good review, and it was the right price and size so it came home.

But after purchase I read some quite curious things about the amp.  It uses a Hypex designed class A amplifier sandwiched between Class D voltage rails. This immediately reminded me of old NAD with their switching rails, as well as the Carver amps.

Recently Stereophile reviewed a more recent NAD integrated, again mentioning the hybrid Class D.

I'm wondering if anyone else has had eyes on at least a block diagram, or reading, or listening impressions.

This is truly a curio of the audio world in my opinion, and therefore fascinating. NAD took a risk in developing and putting in a mass market amp, and it will be interesting to see the trajectory of the technology.