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
OP, if you can source locally a SLI1 ref I would check that out. I have owned CAT preamps for many years, IMHO there really is nothing better in tube preamp land. 
want to explore what tubes can do to the sound (slight warmth, biggest soundstage, better layering etc etc). 
Given what you’re looking for I’d add the Don Sachs linestage that fully tricked out is around $2500, and he offers a trial period that’s obviously nice to have.  Single ended only though.  More on the slightly cooler/less warm side the LTA microZOTL pre would also be well worth a look in your price range.  Best of luck. 
BIG valve preamps are gonna be 'ALL THAT" soon enough..


The big valves are only part of it, he uses ac heaters, which sounds a little warmer, but not too warm, and true point to point wiring. Some manufacturers use hand wiring, but not true point to point wiring.
Used McIntosh C2600 or a used Audio Research would be the way I would go.

Had a Pass XP22, it was excellent.  But I prefer my C2700 with the built in DAC.  Slightly larger soundstage, and the tubes add just that special something.

Note, used it with both my Pass 250.8 and MC462.  

While the amps were different, I noticed more of a difference between the pre-amps.  
Cary, Raven, AH Qualiton 20i, Quicksilver.... especially if $5000.00 is the hard ceiling and you are looking at Rouge, Prima Luna,.
You may want to look Hybrid like Pathos Logos or Dual Classic Mk3 in mono.
lots of choices.