Tube Pre/ Class D Amp - Who has done it?

ADG Duets fronted by a Ayon Audio CD-35 pre/CD player and I love this combo! Speakers are DeVore Super Nines.

I tried a D-Sonic amp with a Modwright 36.5 preamp.  It was a nice amp, crystal clear, excellent for home theater or background music, but sort of lifeless with 2 ch audio.  If you're not familiar with it, the Modwright is a  fine preamp (imo), but not particularly "tubey".  

Admittedly, I have been a tube guy for a long time.  Maybe it was asking too much - I mean, I gave up on solid state amps because to me, there is no doubt that tube amplification sound more like real music -  but it sure would be nice if cl. D were "good enough".  It soured me on class D, for now, but I haven't tried any of the newer GAN versions.  

For Class D I prefer GaN FET. We evaluated and worked with several Class D amps in the past while designing our preamps but being a tube guy, we found GaN FET designs not only sound exceptional, but with their higher input impedance, they mate much better with tube preamplifiers than previous designs.  With other Class D modules, they were either too warm with no sparkle or they were sterile sounding and only good for bass modules  

Personally , I prefer the combination of a DHT preamp and a Hybrid DHT/Gan FET amplifier. 
 

but with their higher input impedance, they mate much better with tube preamplifiers than previous designs.

The seemingly consistent feature among previous generations of Class D amps has been relatively low input impedance. 

In some cases I believe this is to allow for the OEM to produce their own high impedance input stage.  If you make pr eamps, maybe worth taking a gander at incorporating your own front-end. :) @response34 

In some cases I believe this is to allow for the OEM to produce their own high impedance input stage.  If you make pr eamps, maybe worth taking a gander at incorporating your own front-end. :) 
 

Thats what we have done with our Hybrids. 

That’s what we have done with our Hybrid amplifiers. One uses a DHT input stage. I didn’t want to go to far into that as didn’t want the post to look like a promo.