Tube Pre-amp Suggestions.

@kds Using ARC Ref5SE and before that had an Aric Audio Motherlode for a brief run.

I have also thought about going back to Class D amps and just considering PS Audio 1200's. For fun. I'd probably get new speakers before giving up the Coda. The ARC is here to stay but Backert is always an option to consider as a musical preamp.

Manley jumbo shrimp. Great tube preamp with excellent support. Used market around 2k. 

In a reasonable price zone, I’d be curious about preamps from

Quicksilver

Erhard Audio,

Aric Audio,

DeHavilland (if you can find them), 

Supratek

Cary (maybe too pricy)

Rogue (maybe too pricy)

Just perusing the used audio sites and saw a few in your price range to consider

Backert labs  Rhumba 1.3

Audio Research Reference 3

BAT VK 51 SE

Modwright 36.5

These are a few on a well known used audio site.

+1 for Backert Labs!