best preamp under 4000 to match 4b sst

A tube preamp using 6922, 12AU7 or 6SN7 tubes can be "warmed up" by installing warm sounding tubes.

Lamm LL2 Deluxe, Audio Horizons TP 2.1, First Sound Presence Deluxe II all qualify. I'm not familiar with the BAT.

I'd avoid tube preamps based on 6H30 tubes. Not because they aren't excellent, but because you can't "warm them up" by rolling tubes.

If you want warmth I suggest a nice tube preamp. Here are two great choices;

Cary SLP98 - Great sounding pre with loads of warmth and body

Conrad Johnson LS16 - keep an eye out for a used one. This one is so warm and wonderful.

I have owned some of the tube pres mentioned here (Lamm and Joule) and I would still recommend the Dodd preamp which is less expensive than the other two to boot. To Tvad's point, the output impedance of the Dodd is very low for a tube preamp - 200 ohms I think and will drive the amp very easily in terms of impedance matching.

The Dodd preamp looks very interesting, im looking on audiogon if i can find one in maple right now. At the right price i might purchase that one. The red wine isabella seems very nice too but cant seem to find a really mint used one. Thanks for all your comments guys im researching all the pre's mentioned and trying to make a good choice here.

I will doubt finding used RWA Isabella .....at least in a very near future.
Dodd seldom shows up for sell and when it does, it sells in few days max.
But, even for its asking price - it's well worth it.
I owned both ( still have the RWA ) and can asure you that you won't be sorry.

Regards
Mariusz