Tube Preamps.....

Yes with the 565’s being heavily modded by Musical Concepts that made a huge difference in the way they sounded. They never were as bright and leaned on the more neutral side then other Adcoms. After the upgrades completely different amp. I have a friend that has stock 565’s and they sound much better with tubes. that was why I was leaning towards a tube preamp. Thanks for the responses. 

I highly recommend Don Sach's 6SN7-based tube preamp.  It betters any preamp I have had in my system and I have a boatload of them.  Don sells the preamp directly so they are an extremely fine value.  There are lots of review of the preamp on this and other forums.  

Atma-Sphere UV-1 and an Ayre Codex DAC would be my suggestion.
B

Research Rogue Audio.  The RP-1 is $1.5K and the RP-5 is $3.5k .  I really like my RP-1 and the folks at Rogue have been really confidence inspiring on the phone. Only issue is no Balanced out until you get up to the RP-7.

This is a gorgeous sounding preamp in the listings $500 under your budget....

https://www.audiogon.com/listings/lis8fg1h-synthesis-art-in-music-ecstasy-line-level-tube-pre-amp-tu...

No affiliation with the seller but my local dealer Deja Vu Audio is the US importer for Synthesis so I've heard their gear many times. Very transparent organic warm and musical and being Italian very stylish looking.