Tube Preamp to go with Bryston SST2 amp and Magnepan 1.7i speakers

Good luck, it's a critical component with lots of options. Think about future flexibility.

I went Vintage, never been happier, both Phono and FM are the best I've ever had (I'm 72)

McIntosh mx110z

http://www.berners.ch/McIntosh/en/MX110.htm

https://www.positive-feedback.com/Issue77/vintage_mcintosh_experience.htm

My timing was good, they are going up in price.

Even if you don't go Vintage, look at the features that many current equipment have dropped. I wouldn't live without a balance control, and, if you listen to low volume, a properly engaged 'loudness' control keeps the music involving rather than just low level background music.

https://en.wikipedia.org/wiki/Equal-loudness_contour

Quicksilver should fit the bill!
http://quicksilveraudio.com/preamplifiers/

Quicksilver +1

What pre are you using now and what kind of improvements and sound characteristics are you looking for?

With a Bryston amp and 1.7 Maggies I'm thinking about a good tube pre-amp with a good top end. 2 or 3 K is not much budget. I think I would try to demo some at home before I pulled the plug but the Quicksilver is a good starting place or perhaps a used Audio Research.