First tube preamp recommendations (under $5k)


Right now have di20he -> terminator -> he9 -> pass x350.8 -> ATC scm7 / NS5000.
I am thinking of introducing some tubes into my chain. I like the sound I am getting but want to explore what tubes can do to the sound (slight warmth, biggest soundstage, better layering etc etc). Don’t want to go to nuts on price. If price is over $5k would consider if its really exceptional (but for sure not over $10k). Totally fine with used. Balanced would be nice but not mandatory.
So far I am thinking RP7, EVO400, bhk. Any thoughts?
smodtactical
Atma Sphere MP1 or MP3. These are world class tube preamplifiers, very versatile and easy to use. I've tested many european tube preamplifiers (I live in Paris) but finally I've settled down with Atma Sphere. No changes for me any more. 
I strongly disagree with avanti1960. I am currently using a Rogue RP-7 and have found it to have great dynamics and that I got just the right amount of "tubey sweetness" by changing the front pair of 12au7. Those are the only colored tubes in my chain, everything else is as neutral as I can get. It's dead quiet, has great functionality, and sounds tremendous for the money I feel
I like what the ARC 5se does for my Pass 260.8 and ended up putting lesser ARCs in my other systems, a LS28 with a ML, and a LS17se with my Perreaux 3150. All have replaced other tube (Quicksilver) and ss (Classe) gear
Pretty much anything by Audio Research is a good bet.  Used ones are usually just as good as new ones.

I would try a few before making a final decision if I were you.  You are probably going to keep it for a while, so take your time.

Cheers!