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

@ghdprentice I've gone through most permutations of Pass Labs amps, Coda amps, and Audio Note integrated amps (SOTO SE and Cobra being my favorite). Current reference is an LTA Microzotl Level 2 preamp as a reference McGary SA1E tube amp.  Before that I had a Supratek Cabernet.  

I use Class D Audio amps in my secondary theater system and even listen to music on them on occasion.  I preferred them over the PS Audio M700 which as I stated earlier I greatly disliked.  I've had the opportunity to demo the AGD Audion MKIII at Axpona over the course of a couple days and I loved them, but I need to try it in my space first.

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