The MF2550 - not just an ordinary amplifier

Feb 3, 2012
I was looking for the particular MF2500 series tag... Anyway this one I'll keep as brief as possible, since it's now past 5am, and just about to finish up my late night / early am session.

One of the monoblocks had to go upto QLD for a service, so my trusted good CJ mate lent me this SS beast, assuring me that it "will drive" the CLX's to their full potential. Ah! So I thought great, another good one from CJ, brings back memories of their previous MF series power amps, which had the MOSFET output stage.

CJ redesigned their MF series and launched a massive mothership called the Premier 350. This was some serious amp, rated at 350w of CJ's musicality and finesse, it could drive anything! Sadly no longer in production, CJ continued to focus their efforts in tube design, which they've been doing since the 60's...

A few other SS amps came and went, along with a few Hybrids, input stage being tubes and output stage being Mosfets. Those were great but always seemed to fall short compared to their top line tube designs.

Now we have the latest iteration of that production line, introducing the MF2550 but sadly this has been discontinued as well! CJ then changed ownership, Mr. C & J went fishing and now Jeff Fischel is in charge. He's a perfectionist and for whatever reason, he's decided not to proceed with another SS... For now just focusing on all tube design.

So, I brought this thing home, hauled it in to the living room, after correcting my hernia, dam thing weighs a tonne, (need to beef up that bench press or perhaps the deadlift...) Hooked it up, fired it up and oh my! What a performance!

This is designed with a MOSFET gain at the input stage, if I'm correct, then an additional buffer stage directly coupled to an output stage consisting of Bi-polar devices, the very same used in the Premier 350.
Rated about 100w less than the Prem 350, it can put out a very healthy and lethal dose of 250w of CJ power and finesse!

Has total grip on the stats, handles that notorious impedence drop of 0.7 ohms effortlessly and handles the top end which soars to over 20 ohms at lightening speed, no stress on this amp whatsoever!

The highs are very airy, and extend beyond the horizon, the mids are very smooth, plenty of open detail, air around the instruments, those subtle nuances, the soundstage depth and imaging are superb! And the bass, very very nice! It's super fast, tight, articulate and very agile, it also captures all the low notes, provided your speakers can deliver it. The specs on the CLX's bass is not extended to anywhere near 30Hz or 40Hz for that matter but those are just specs. Once you listen you'll know straight away what kind of superlative bass I'm referring to.

I've used and sold many SS amps in the past, from ARC, Krell, Plinius, Parasound, Bryston, Jeff Rowland, and Mark Levinson. These are all top dog brands and makes, and the few SS that have me fairly excited have been Pass Labs of lately, and of course my all time favourite, the Relentless amps by Dan D'Augostino.

Now, similar to CH Precision and Solution amplifiers, the Relentless are in that category of 200 grand price tag and above, depending on how much Class A bias you wish to choose. However, I do know it's definitely unfair to compare that ultra high-end category with this particular SS amp. But that's just the beauty of true high-end, and this is definitely not just an ordinary amplifier, hell no!

Even at the finest and stunning power of superb performance on the Relentless monoblocks, the CJ MF2550 can hold itself steady all the way towards the most notorious impedence swing, and it handled it just beautifully!

For those of you who do own the Dan D' Momentums or Relentless amps, no disrespect at all, in fact hats off to you! All I'm saying is that if anyone is very serious in putting out about 10 grand of pure power amplification at its finest, I very highly recommend this one!

Well done to CJ's team and at the same time, sad to see it go... Which is why this is one of a kind, simply because this is the very last MF2500 series you're going to ever find!

Cheers to all and keep those tunes alive
Best, RJ
Likes: Marcus

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