Please recommend a good Tube preamp.

I agree with Czbbcl, the Conrad Johnson Pre in your price range. Great company, good support, reliable, woderfully musical. All the virtues of a tube pre, great midrange, sounstage etc, but quiet and reliable. I have heard others but use the Premier 17 and do not forsee changing

Cary SLP-98 with factory options: oil caps and direct coupling (not sure how compatible the latter is with SS amps, however). Ballsy yet refined w/good NOS 6SN7s...NOT for playing background music! Comes with remote. Replaced a $5K tube linestage in my system and I've never looked back.

Do a search here on First Sound, and read the soundstage review. It's amazing. Ditto the Supratek recommendation.

Have heard great thing about Aestetix. Of course excellent choices also available from VAC and VTL, CJ and so on.... man ther are MANY good ones to be had!

If budget is of no concern:-
CAT SL1 Ultimate Mk2
First Sound Presence Deluxe
Lamm LL2

A lot of good suggestions above, and a few interesting items that I have not yet heard (e.g., First Sound Presence Delux). Not knowing what sound/change you are going for, I would say that everyone's suggestion is merely a recommendation to AUDITION these items before buying, unless you enjoy the game of trading items.

Here are my suggestions on items to consider. Some are pretty hard to come by, but if you are game, they are worthy contenders. To me, these have that something extra, hard to describe, that make music sound vibrant and harmonically rich. They are:

1. Audionote (u.k.) (Anying from the relatively modest M-3 through crazy-expensive M-10)

2. Emotive Audio (Sira or the quite expensive but amazing Epifania)

3. Deja Vu linestage or preamp (something made locally in the D.C. metropolitan area by Deja Vu Audio, a McLean, Va. dealer).