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
@liamowen Ya this engineer in our audio discord Sonic Visions loves Conrad Johnson. Says their designs are incredible.
@JG2077 seems like the black path is the CAT to get.
@smodtactical,  see if you can audition the CAT near you.   Ask the seller if the unit has been serviced? In one of my systems,  CAT replaced an AR3. Excellent suggestions have been provided to you.  Good luck and enjoy the search. 

Best,
Jose