The MF2550 - not just an ordinary amplifier

bgiliberti

Well-Known Member
Mar 28, 2012
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Greetings from down unda! Happy holidays and seasons Greetings. Here's wishing you all a peaceful and safe Xmas.

Well finally the monoblocks were dropped off today for a final SE upgrade with all the necessary goodies... so whiles that's taking place, which will be ready in about a week after fully running in and final tests, I picked up this beauty yet again!

Although made in the exact same factory by the exact same team and offered by the exact same brand as the tube monoblocks, yet two completely different sounds. The 2550SE is definitely no ordinary amplifier. In comparison to the monoblocks, it's much smoother, very nice extended bass, tight grip on the CLX's and has an effortless sense of drive. The highs are not as extended as the tube amplifiers, where they sort of have this enveloping sound to it, warmth ambience wraps around you and the CLX's simply disappear into thin air!

Upon the first few notes then well into half an hour the bass was lacking from the MF2550SE. Everything else was there, mid bass slam, attack and speed, great midband dynamics and all that sort of thing but where was the bottom end drive... level settings were low, only at 20 on the CT5. Then turned it up to 25...30 still nothing much. Then turned it up to 40 and above- wow! Look out! There she goes... it just shifted gears, like a Ferrari or Lambo hitting 0 - 100 in less than 4secs it just took off! Now we're talking, plenty of bottom grunt and tremendous drive, nothing to worry about and absolute accuracy, no flinching one bit.

However, this is certainly not the type of sound I prefer, I don't mind it but the MF2550SE isn't meant for soft to moderate listening. It reminds me so much of the ACT2 and Premier 350 combination, that was like Canon fire on certain levels. Very explosive, will go from a silent flutter to a thunderous bang in a blink of an eye, and the CLX's or horns can certainly deliver this, including other panel type speakers like full range ribbons. This thing can certainly deliver the goods if one was looking for less maintenance, no hassles with tubes and a truly live experience, if you prefer a pretty loud presentation.

As for me, I prefer the further extended highs, and low level detail tube monoblocks offer, plus the glorious midrange that tubes deliver and that is so engaging, it's the first thing you notice when driving with tube amplifiers. Which one do I like? Well both I guess, I could happily own this MF2550SE amplifier with no hesitation. It would be at the top of my list, amongst the many lofty ones I've heard, including the Pass Labs XS series and my all time favourite, the Relentless monoblocks. However, at a more decent and accessible price range, this would be the one.

Which one do I prefer? Obviously the tube monoblocks, afterall tubes are my passion with full range stats. Once in a while it's certainly nice to experience something like this, and just enjoy it for what it offers. I would think it's a better amplifier overall in design and layout, plus the ability to control reactive loudspeaker loads. It probably also has a higher Class A rating before it switches into Class AB, I guess this is where the LF grip takes place. However, on low levels it just falls asleep. It doesn't kick in at all, very flat and just plays tunes... unlike tubes, I could listen for endless hours and enjoy every moment being fully immersed in the presentation regardless of levels. And most of my sessions are after midnight.

Then again perhaps on a different system, one with full range ribbons, perhaps Maggie's, Apogee's or Alsyvox this MF2550SE driving any of those types of panel speakers would be superb!

So cheers to the MF2550SE! Not just an ordinary amplifier, no doubt! For those of you who still use one, it's definitely a one of a kind and sadly no longer in production.

All the very best, RJ

Oh! And most of all, enjoy those fine tunes!
RJ, Happy Holidays to you as well!

If you haven't been using the the MF-2550SE since you got the monoblocks, the Teflon caps probably need to be broken in again. I found that with my Classic SE preamp after it went unused for 5 months.
 
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Big Dog RJ

Well-Known Member
Feb 3, 2012
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Yes very true mate.
In fact I noticed that with power amplifiers as well, not just preamps as I had thought initially. Not that I didn't think power amplifiers take that long but with preamps, what I noticed is that when those Teflons really run in, all of sudden it kicks in and takes a different dimension. Whereas with power amplifiers it's a gradual process of refinement and things take shape or a more perfect form so to speak.

However, one thing for sure is that the MF2550SE definitely needs some humpty for it to deliver what it's capable of. We're just listening to a few Adele LP's (not really audiophile) but the Mrs and kiddo wanted to have a listen. Anything below 40 on vinyl playback is pretty flat. Hence, I've got the levels set at 46 on the CT5 at the moment and the soundstage opens up nicely as it should.

I truly appreciate your Classic SE preamp, that was one of my all time best in value and best performance preamps in the CJ line up. It was one of those really great things you come across once in a lifetime and sadly both these units are no longer in production. Now CJ offers only a handful of gear, I guess JF has his reasons.

Good to also note that both the ART300's and ART27A won amplifiers of the year awards. Great stuff indeed!

Cheers mate, and enjoy those fine tunes!
Best, RJ
 

Big Dog RJ

Well-Known Member
Feb 3, 2012
803
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Melbourne
Mmm... well things have taken a slightly different twist or shall I say a fairly major twist!

Extremely delighted to report that I've managed to get the level setting down to 32 on the CT5. Each step is 0.7dB, so from my last post wich was last week Sunday where the level was set at 45-46 to get going... now it's Saturday morning 3:15am and that's a significant drop! It's sounding superb!

I noticed straight away the LF detail and control it has on the CLX's, that's what it ought to be. I still prefer the midrange and extended airy highs from tubes, that added warmth and ability to float an image directly in front of you, those extraordinary details are with the tube monoblocks, there's no doubt. However, I'm really getting used to this beautiful amplifier, I've played nearly 6 different albums from Norah Jones, Liz Wright to Holly Cole and I can't fault it in any way. It's just different and has a wonderful sense of musicality to it, so I wouldn't compare it to tube amplifiers and try to judge which one's better, they are just very very different!

Now, I've got to find a hiding spot for this one, as it's definitely not easy to hide something with such a huge shiny gold faceplate... oh boy, dog house here we come.

Those Teflons really take awfully long... and I mean awfully long. This is straight listening for 6 hours and still setting in. Never experienced this level of refinement from CJ's MF2550SE, no ordinary amplifier!

Cheers maties, enjoy those fine tunes!
RJ
 

thedudeabides

Well-Known Member
Jan 16, 2011
1,510
179
485
Alto, NM
Extremely delighted to report that I've managed to get the level setting down to 32 on the CT5. Each step is 0.7dB, so from my last post wich was last week Sunday where the level was set at 45-46 to get going... now it's Saturday morning 3:15am and that's a significant drop! It's sounding superb!
RJ
Hi Big Dog,

I assume you change volume levels for each CD. My ET5 volume ranges from 25 to 68 depending on the disc. And I document the volume for every disc I play, with date, to establish a reference volume.

Best,

Gordon
 

Big Dog RJ

Well-Known Member
Feb 3, 2012
803
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373
Melbourne
G'day Gordon,

Nice one on the ET5, a fine pre-amplifier! You mentioned changing levels from a range of 25 - 68... 25 to around 40/45 is pretty loud... 68 is way too loud for me! My ears will pop, no way would I listen to that level nor would I allow anyone to increase the volume on the remote to such high levels.

Anyway, I guess you have your reasons and I respect you for that. Also you're a current CJ owner! Afterall "it just sounds right."

Yes, I do change levels from each CD/ SACD played. However, with the Esoteric digital gear, the levels aren't as erratic compared to the previous Mac sacd player I was using. On that particular digital source I would have to adjust each time, I guess it was more sensitive to varied levels in recordings, good, bad and reference quality.

As I was closing my listening session last morning around 4am, I noticed the levels nicely settled in around the 30-31 mark. I could certainly hear more of the recording, much clearer with all the fine detail. Guess these subtle details and intricate nuances are more prominent thanks to the Gaia's performing so well. I'm really happy with the end result, although it took me nearly two years to decide.

Cheers mate, and enjoy those fine tunes!
RJ
 

thedudeabides

Well-Known Member
Jan 16, 2011
1,510
179
485
Alto, NM
Hi RJ,

Please note I typically listen at 85db+/- so it really isn't overbearing from a loudness perspective. In fact, less really is more. Average volume setting is between 45 and 55. Best,

Gordon
 

Big Dog RJ

Well-Known Member
Feb 3, 2012
803
94
373
Melbourne
Gordon, ok now that makes sense. 45 is a good reference point for realistic levels. Was just wondering, are your speakers on low efficiency or fairly efficient would you say?

Also depending on output level from source to preamp and the input sensitivity on the power amplifier, then finally through the speakers... all this input / output sensitivity ratings are critical. Another significant thing I noticed on vinyl playback, I would have to turn things up a bit but not so on digital playback.

However, that aspect started happening after I used the MF2550SE, whereas with the monoblocks this was not the case.
Cheers, RJ
 
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