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

@erik_squires 

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

FWIW the input impedance of our class D amps is 100K single-ended or balanced. Anything can drive them.

So - I’ve been (re)assembling my cabin system. It now consists of the Atmasphere MP-1 mk 3.3 preamp (tube) and Atmasphere Class D monos and I’m pleased to say it’s a very good combination. It’s different than my primary system which is solid state preamp going into a class A/B amp but they’re both very satisfying even though they bring different things to the table. 

I’ve had class D amps before (PS Audio Stellar S300, NAD M22, NAD M33) but they all failed to fully satisfy. They weren’t bad, but they also weren’t that great and I’ve since sold them. The Atmasphere Class Ds are notably more musical and a terrific value. I will say they’re not quite as good as my Class A/B amp to which i directly compared them. But they were also a LOT less expensive. 

So, my recent experience is a tube preamp/class D combo is a nice pairing. 

I have been testing our various tube preamps with GaN FET amps and our hybrid  amps (one uses a 12AU7 input stage while the other uses DHT-currently running 2A3’s)

Being a bit biased, my preference is our 2A3 only linestage. The GaN FET modules on their own have a 100K input impedance and the hybrids are min. 100k
The 2A3 preamp utilizes transformer coupled inputs with single ended output  

With the higher input impedance and the better quality of todays Class D amps, it is not to hard to get the sound you want with a tube preamp  just be careful with the synergy with high output preamps with some Class D/solid state low impedance inputs. As always