bryston 28bsst2 / mag's 3.7

Some more info would be helpful. What preamp are you using now, and what aspects of sound reproduction are most important to you and what specifically are you looking to improve upon over what you have now? Until we know these things, as Zd alluded to, you'll just get people's personal preferences which likely have nothing to do with what you may be looking for. And budget would be helpful too. Basically, the more info you give us the better and more useful recommendations you'll get here.

I had 3.6R's for years, and liked the match with Bryston very much (although I must say the Sanders Magtech was by far the best amp I ever used with Maggies, followed closely by the Cary MB500's) and when I first got those together I had a Bryston preamp.

I eventually switched to a Cary SLP98p F1, that was the hot rodded version sold through Upscale Audio. I still have the preamp, and now that I'm in a smaller room, I've traded my 3.6R's for a super MMG system (with a Bryston 4BSST2 btw).

I love the sound of Cary preamps, it's decidedly warm, and that balances, to my ear, the sound of high powered planar speakers with matching amplification.

The SLP 05 or SLP98 models will work very well for you.

I've also always loved the ARC preamps, but they are not as warm as the Cary's.

Good luck, cheers.

I've had multiple systems of Maggies partnered with Bryston amps and tube preamps,which in my opinion is a requirement to flesh out that linear Bryston sound.What worked well for me were Audio Research products,specifically LS 15/16,Ref 3.
Audio Horizons preamps are also a seamless match.

Take a look at the BAT VK-43SE SS preamp. I have used the Bat VK-42SE (previous model) with many Bryston amps (up to 7B-SST) and it was a great match. I love the BAT pre-amp. I used to own the Bryson BP25 but that was a very long time ago and nowhere in the class of the BAT.

Yeah, Bryston preamps are not to the level of their amps, imo.