I have a Sonograph SA-250 (I see there is one for sale on this site right now) and although I have not used it in awhile due to equipment swapping, in my opinion it is a very fine sounding amp. I believe this is a Mosfet amp.
Conrad Johnson SS amps
I am currently looking for a new power amplifier to drive my Martin Logan CLSIIs (4ohm load). I am deciding between CJ's MF2250 and MF2500. I was wondering what the difference was between the the stock model and the "A" model. ie: MF2250 vs. MF2250A. I would also like to know if they can they be bridged? Would I get better results using two MF2250 amps or a single MF2500 amp?