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
In my opinion the preamp is a good place to start as far as introducing tubes. I would consider a Backert Labs Rumba which can be purchased new under your stated goal of $5k.
@scottya118 Thanks I am looking at the backert.
Right now though im leaning heavily to Aric audio's motherlode 2. He seems to have unanimous praise. One guy on audiogon actually preferred it over his  Pass XP22.
Stay away from Rogue Audio Go with the Cary  you can't go wrong some old rca and mullards. Oh yeah