Conrad Johnson MF2250A / MF2500A vs CJ MF2275SE / MF2550SE

For years, I have known the differences in build, but has anyone done any detailed listening comparisons?

47ghibli--

I have shared some thoughts on these amps. To answer your question more directly. Yes, I have owned and used them both, as well as the Premier 350 and CA 200 (ss amps, plus 4 other CJ tube amps). Have I listened to the 2500 and 2550 side by side? No, as that was never possible due to the age gap between the two amps and I simply never kept the 2500. I do not think many have been able to doing that comparison. As I wrote, the reviews on the MF 2550SE are accurate and describe the sound in detail. But in simple terms: the MF 2500/2500A are musical with good detail and sound stage. The MF2550SE is in another class and is far superior in sound, detail, control, and musicality. You hear more with the 2550SE and its is more pleasing to the ear. With the 2500 you are somewhere in the audience. With the 2550SE you are on stage hearing the music as the musician do. You hear detail and harmonics with wonderful placement. You are engulfed by the music and able to hear what the 2500/2500A did not deliver. If you want a SS amp that you can keep, then the 2550SE is that amp.  If you do not need to extra power then the 2275SE will deliver the same results. Both amps are identical except for their power.

Thanks again for your detailed response.  Sounds like I may like to upgrade to the later amp from my MF2250A.  I am reluctant to do so because it has had little use and is perfect cosmetically.  I bought it from the original owner that lived near CJ.

He took it to the factory and they made sure it was to spec, upgraded it to "A" and shipped it directly to me.

It hasn't seen a lot of use having been in rotation with my VTL Stereo 70 and Manley Retro 100 monos.