Which SS pre-amp Muse, Mus. Fid., Krell

I'm looking for suggestions on a ss pre-amp to upgrade my system. I'm currently using an old Bryston 0.5b. My system has been getting better slowly, but I use 5 sources and it sits on all day so few input and tubes are out. I listen almost exclusively to classical music. My speakers are Magnepan 1.5QRs and I'm using and ARCAM CD and Teac DAT and several other sources - with TMC cables. For now my amp is a B&K Reference 4420 which accepts XLR or single ended (but this will probably be the next unit I change). A phono input is a plus but not essential. The units I've been looking at are as follows:

Bryston BP-20 or BP-25
Krell KSP-7B
Muse Model Three
Musical Fidelity A3cr pre

With the exception of the musical fidelity I'm looking at these used and all are around $1k. I would really appreciate suggestions/advice.
I haven't heard the Bryston but out of the rest I would recommend the Musical Fidelity A3cr. Tremendous sound quality for the money.
I have a Bryston SP-1 preamp, plus Bryston power amps. If I were looking for a moderately priced stereo preamp today, I'd seriously consider the Adcom GFP-750. Even at its full retail price it is a superb unit, and as a used unit it is, to my mind, the best SS preamp value you can buy.
I have the Muse 3 w external power supply. Its a faboulus preamp. Truly high end sound. I have compared it at home with a AYRE K1X a 7000$ wich also is very good pre. The muse is in the same league altough the sounds differ a bit.