Tube pre for class d recommendations

Interesting Ralph.
I have 2 foundation research LC2...one grounded and the other lifted ...done by Ed....that I used. Meaning, I was really giving it the old college try to make it work.

orpheus10, I’m not aware of a class D preamp. 

I’m very pleased with the Freya, Owen. Had it a couple of years now (3?) and no problems. You can spend more, you can buy better but at $700 it is a solid bargain. 5 year warranty and there’s a 15 day money back return option (less 5% restocking and shipping costs) if you don’t like it.

The first (and maybe even some of the second set) NOS Russian tubes that were supplied with the Freya were a little noisy. Schiit replaced them promptly no problem, though now running NOS American tubes. Other than occasional tube noise on rare occasions, the unit is very quiet. Volume full up with nothing playing there is NO noise at the speakers...ear 2" from the tweeter, etc. The resistor ladder type volume control does click when you change volume settings but I’ve heard the same from a Conrad Johnson pre I auditioned.

Other than ensuring impedance compatibility, as Atmasphere mentions [ensure load impedance of amp is at least 10x (some say 20x) output impedance of preamp] I don’t know any reason a Class D amp wouldn’t work with a will-chosen tube pre-amp.

As for everything audio, there are always haters. Wolf Garcia is another Freya user and advocate. Check out some of his posts on the topic. Good luck.

I am an owner of Don Sach's 6SN7-based tube preamp.  It is better than any preamp I have had in my system.  It is a bespoke preamp that has gone through several iterations of upgrades to its current state.  For around $2700 or so, you will have a SOTA tube preamp that will outperform preamps costing vastly more money.