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EMM Labs MTRX monoblock amplifiers Review

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Do you find yourself absolutely in love with the midrange purity and three-dimensional soundstage that are the hallmark of low power, single-ended triode designs, but wishing for more power or more extension at the frequency extremes or even a lower noise floor? If so, then you may want to consider Ed Meitner’s newest creation, the MTRX amplifiers. According to the manufacturer, they are fully balanced; feature a bandwidth of DC to 500kHz at full power; have a damping factor of 1,000; deliver 1,500 watts at 4 ohms and 3,000 watts at 2 ohms; use a MOSFET output stage; and cost $130k the pair. Just to name a few specs.

Physically, they are imposing and weigh 220 pounds each. Each amp requires a dedicated 220 volt electrical service, although they may be ordered for 110. All of this would mean absolutely nothing were these amps not so exceptional sonically.

Prior to the arrival of these amps, it was necessary to install two 220 volt electrical circuits in my listening room. While this sounds fairly straightforward, it is not necessarily the case when you live, as I do, in a fifty-year-old house. In the end, the electrician installed a new electrical sub-panel, two 50’ runs of 8 gauge wire (which required cutting into an existing wall and subsequently re-sheet rocking and painting the wall), and installation of new Furutech RTX rhodium plated outlets terminated for Schuko plugs. Much of the “break in” which I detail in the remainder of this article may well have been the new wiring and not the amps.


The amps arrive

Perhaps I am getting ahead of myself. The EMM Labs MTRX amps arrived on an overcast day in early summer. Each was cradled in an aluminum flight case, which fortunately had wheels underneath to aid in movement. Once again, my son, a Marine, and one of his friends were kind enough to move the flight cases into my music room, then lift the amps out of the crates and install them between my speakers. The only recompense which they would accept was beer and pizza. A lot of beer, as it turned out. Later that evening after reading the user instructions, I engaged the ON switch on the rear of each (main power). The amps immediately went into standby mode as indicated by a band of red light visible underneath the front of each chassis. Initially, the light flashed but within seconds changed to a continuous state when the amps stabilized. I then pressed the front panel switch and the light quickly changed from red to a soft blue, again initially pulsing until the amp stabilized. At no time was there any noise, pops or other indication that the amp was stabilizing.

I was warned that even though the amps had been broken-in at the factory, it would take about 72 hours of continuous play for them to reach their best. While they were very good after about an hour, they improved rather markedly as they approached the 72-hour mark.  Improvements were most noticeable in the form of increased air around instruments, more top end extension and delicacy, and increased three-dimensionality.


Listening – the first 72 hours/no tweaks

As is often the case, my friend Earl attended the initial listening session. We have a weekly listening session on Wednesday evenings, but occasionally meet to listen at other times. On an ECM jazz recording by Colin Vallon, Le Vent, treble detail on cymbals was exceptional. We could immediately tell the location of the cymbal, what was striking it, and where on the cymbal, meaning edge, bell, center, etc, it was being struck. There was an incredible amount of detail. As we moved into the second cut, the music became more intense and increased in tempo. Both of us became more involved emotionally than on the first cut. There are some wonderful things that this drummer does with his snare and toms to push the music along (rim shots and several delicate bass configurations were extremely nice). The EMM Labs MTRX, even at this early point, were clearly superior in resolution of musical detail and leading edge definition to my reference, the Audio Note Kegon Balanced.

Next, we played Sarah McLaughlin’s Stumbling Toward Ecstasy (Classic Records, 45 rpm re-issue). The detail was stunning! The producer of the album was clearly playing some tricks with the sound to make it a bit of a mysterious jumble. The EMM Labs’ revealed all of his tricks. In spite of that, Sarah’s voice was not quite as sensual and sexy as it can be when everything is “right.” Subsequently, on a Wayne Shorter album, upper midrange detail was amazing with startlingly clean and clear wind choirs. However, the bass drum and the edge of the electric bass guitar were not quite as visceral as they can be and the kick of the bass was less pronounced, definitely there, but not as round and whole or with the metallic clarity of attack and string tone that I would normally expect.


The plot thickens

Just when you think that you know how something sounds, you make a slight change which has a significant impact on the sound. About three weeks into my listening, I was able to get my son to help me place Finite Elemente Cerabases under each of the EMM Labs MTRX. Until that point, the amps had rested directly on the floor on their own feet. Suddenly, there was more bass, perhaps too much on some things, but more importantly, the EMM Labs’ began to exhibit some of that magic which makes them so special. Again, in a joint listening session with Earl, we played Kurt Rosenwinkel’s The Remedy, Live at the Village Vanguard, which we have played on various systems numerous times. The bass was well balanced and the illusion created was remarkably close to live. Air and placement were superb! Next came a Swedish jazz CD by Solvieg named Silver. Again the sound was stunning, particularly in the highs. My only minor criticism was that the EMM Labs MTRX were so revealing that we could tell that the mix-down engineer had played a bit with Solvieg’s voice. The listening session ended with some Hugo Wolfe. There was some occasional very slight metallic hardness with the EMM Labs’, as there has always been with this recording, but less; while this was an improvement, it is difficult to say whether it was more accurate. “Realism” was as high as it gets and the strings were lush.

As I shut the system down, I thought to myself that almost anyone listening to these amps on the Acapella Triolons would be hard pressed to imagine that the sound could get much better or more realistic. The level of detail with the EMM Labs MTRX can, at times, be a bit overwhelming, and by this I do not want to suggest that some frequency bands are over emphasized, as the level of detail is consistent throughout the frequency range. The same can be said for dynamics. Unlike almost any other solid-state amp out there, no frequency band is dynamically favored over another.

The key to the EMM Labs MTRX’s performance is their ability, better than anything else that I have heard, to separate instrument and voice from orchestra and choir, and their consistent top-to-bottom revelation of detail. The EMM Labs have marvelous detail and give a tremendous sense of “being there” in many respects. However, I am occasionally bothered when very subtle bass cues seem to be missing on the MTRX. I am very aware of bass guitar and drums. I am hearing less of the palpable thud and thump of bass drums with the EMM Labs MTRX than I am used to hearing. There is a certain enjoyment in listening to a swing band and hearing a drummer who is very solid, tempo-wise, with a strong bass drum, because the bass guitar and drums are supposed to work together to be the rhythm section and there are few things as fun as standing with the drummer and getting right down in it such that the kicks are in sync.

7 Responses to EMM Labs MTRX monoblock amplifiers Review

  1. alan trahern says:

    Are they now in permanent residence?

  2. Howard says:

    You bought them?! Sheesh! Are they really better than Halcro(are they still relevant), Solution and Boulder?

  3. Fred Crowder says:

    The EMM amps are in the system for the long term, sitting next to the Balanced Kegons which I am keeping as part of my reference. With response to the Soulutions amps, I have not heard them in my home system so I must at this point withhold judgement. With respect to the Boulders, they are not my cup of tea and clearly are not competitive with the EMM’s. I now have spent extensive time with the amps on my Triolons and on the Marten Supreme 2 speakers and in both cases, the amps were superb.


  4. Alex Cherbinski says:

    What preamp are you using with these, or did I miss it in the review ?

  5. Fred Crowder says:

    I continue to use an Einstein tubed preamp in which I have substituted N.O.S. Siemens tubes from the 1970’s in place of the stock tubes on the inputs, replaced the stock power cord with one from Acapella, and replaced the feet with Finite Elemente Cerabases; however, I will be getting in the EMM Labs PRE as well as the Audio Note M10 Signature for review during the next several months, so things may change. I tend to change components infrequently, only when I find something which is significantly better.

  6. Hello Fred,

    A year has passed since you reviewed/acquired these MTRX amps. Have they continued to improve – particularly in the bass frequencies that you made note of in your review?
    Also, have you stayed with the Cerabases, or have to tried anything else? Like Stillpoints perhaps?
    Finally, have you had the opportunity to hear the MTRX2’s and if so, what was your perception of them?
    No, this is the real “finally”…. any word on when/whether EMM Labs will be bringing out a linestage to match up with the MTRX/2’s and the TX-2/DA-2 gear.
    Thanks for your time.

  7. Fred Crowder says:

    It is hard to believe that it has been a year since the initial MTRX review was published. They have in fact continued to improve but therein lies a story. My amps were early production. In the past year, there are been two updates which have been incorporated into the design and made available to all owners of the earlier amps. Ed Meitner installed both of these modifications into my amps. The first was a new input board which increased bandwidth from 500 KHz to 1 MHz and decreased settling time by half. The other was a change to the power supply for the input board (note that the input board has a separate power supply from the output section). The two updates taken together resulted in a rather audible improvement to the sound and addressed the perceived issues with the bass frequencies as well as increasing palpability and bass slam and dynamics which were already good.

    I have stayed with the Cerebases and continue to be happy with them. The weight of the amps (230#) makes experimenting with feet a bit more difficult but this is something which I would like to explore. Stillpoints (particularly the Ultra 6’s would be an excellent choice). I have not heard the MTRX2 if by that you mean the smaller version of the amps (only 180# per side). I have spoken with Ed about them and I have every reason to believe that they incorporate the same circuitry but are only 1000 watts at 4 ohms vs 1500.

    Finally the new preamp should be available early next year and I will be getting a review sample. In the interim, Ed has incorporated much of the technology in the latest version of the existing preamp.

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