Musical Fidelity M2si Integrated Amplifier Review

Please see This Post for a detailed rundown of our reference system.


It’s been a long time since a Musical Fidelity component passed through my system. My one and only experience with the brand was the single-box version of the classic A1 amplifier which was a wonderful sounding thing, though in true British fashion it had many reliability foibles. Fast forward a few decades since its launch, however, and we now find the brand under the ownership of long-time Austrian distributor Audio Tuning GMBH, parent company of Pro-Ject Audio Systems.

I’ve always admired the brand’s emphasis on measured technical performance over the audiophile buzzwords of the day, and their current range is no different. From the M1 right up to the no-compromise M8, the range seems, on paper at least, to be packed with sensible designs and no-nonsense products with excellent technical performance. A great many hi-fi components of today owe a lot to Musical Fidelity designs. The brand was one of the first to produce a so-called ‘super integrated’ amplifier with the 1992 A1000, and the X series in 1997 were some of the first components to inspire designs that differed from the usual rectangular boxes often associated with traditional hi-fi.

I’ve recently had a couple of reliability concerns with my current amplification, and have been looking for a better digital front end, so I figured now would be as good a time as any to see what Musical Fidelity have to offer. To get an idea of the quality of product on offer, and the current sound signature, I asked for the M2s pairing, one of the newest to be launched since the company changed hands.

M2si Blk Front

Features

The M2s range includes an integrated amplifier and CD player. This review will focus on the former, though naturally the two saw extensive use as a pair throughout the review. The M2si is a simple no-frills analogue integrated amplifier. You get neither digital inputs nor a phono stage; there are no flashy displays, only a minimal selection of LEDs to indicate the status of various functions. What you do get however for your £799 (UK SRP) are 6 line-level inputs, one of them with a home theatre bypass function, preamp and line-level tape outputs and a remote control.

That might not sound like much but consider this. Most of the cost of an amplifier is not in the electronic components, most of which cost pennies each, but in its casework, cooling heatsinks and the power transformer. In sacrificing superfluous features, the M2si chassis is more solid than most at this price and it’s powered by a hefty toroidal transformer feeding a linear power supply with separate supplies for the pre and power amplification stages. This allows the class AB amplifiers to comfortably deliver a rated 60W per channel (18dBW), with more than enough current delivery to produce copious amounts of low end from a wide variety of speakers.

And while there’s certainly nothing wrong with having a DAC or phono stage built into your integrated amp, chances are it will be easily bettered by an off-board unit. So it makes sense to put the money into the parts that you’ll actually use. Perhaps the only missing feature I would have liked to have seen is a headphone socket. Even if it didn’t have a dedicated amp, feeding a headphone jack from the power amp with a couple of dropping resistors costs very little. Thankfully the tape outputs can be used to feed an external headphone amp, and are a welcome inclusion in an age where many integrated amps are dropping line-level outputs entirely.

Specs And Measurements

The M2si is built around a class A/B amplifier with a single pair of output devices per channel. It delivers an underrated 60.5W per channel into an 8 ohm load (22V RMS, 20Hz-20kHz) with a claimed 25 amps of max current delivery (peak to peak). Power at the onset of clipping is actually closer to 78W (25V RMS) into an 8 ohm load, almost doubling to 137W per channel into a 4 ohm load from 20Hz to 20kHz. Rated frequency response is flat to within -0.1dB from 10Hz to 20kHz, though during my tests this extended to beyond 50kHz which is excellent.

Rated signal to noise ratio is 96dB (A-weighted), though no reference is given for this measurement. In normal operation with sensitive speakers I can hear only a faint hiss when up close to the speaker and nothing from a foot away, so I would say that the M2si performs well, and better than many, in this area. Only when passing’s the 0dB point of the volume control does the noise rise considerably, but in the unlikely event that you did reach that point you either have insensitive speakers which wouldn’t present an issue, or the music is so loud that any noise exists so far below the level of the music as to be a non issue.

Preamp gain is 4.5x (+13dB) at maximum volume, and power amplifier gain is fixed at 34x (+31dB).

The audio signal path remains entirely analogue through the volume control which uses a laser trimmed attenuator, essentially a very fancy controller incorporating high precision SMD resistors laser trimmed to extraordinarily high tolerances, resulting in a stepped attenuator with superb tracking and channel balance but also low noise and distortion. A variable gain control block varies the gain based on a control voltage, giving a logarithmic volume control with excellent performance and load driving ability at any volume level.

The volume control itself is motorised. Personally, I much prefer microprocessor control with a digital encoder which gives smoother operation particularly when using a remote control, though the M2si does go some way to overcoming this. When operating the volume control remotely, the volume will be gently nudged upwards in a few small steps before rising continuously, which does at least allow for adjustment in smaller steps; particularly important with sensitive speakers which don’t need a lot of encouragement to go very loud indeed.

Input switching is solid-state and thus totally silent. The volume is muted during the fraction of a second that it takes for the inputs to switch, and ramped quickly up to the previous state. This is a nice attention to detail which is barely noticeable but prevents sudden and potentially damaging noises if you’re switching between active sources at high volume. There is some low-level crosstalk between inputs with active sources, but it’s noticeable only at high volume.

Initial Impressions

The packaging is lavish and certainly gives a great impression with thick foam inserts supporting the amp which is covered by a drawstring felt bag. Included are an IEC cable, remote, documentation and cotton gloves to avoid leaving prints on the finish during installation. Though it has to be said that the paint finish of this casework should certainly be more durable than most.

Though weighing only 9.2KG the M2si certainly is a hefty thing and is of an all-metal construction with a wrap-around top panel hiding unsightly fasteners beneath. Both components are available in black or silver finishes. The front fascia has a slight bevel running along the top and bottom and is dominated by the large metal volume knob and neat rows of buttons for inputs and power. That’s it. There are no tone or balance controls; a few blue LEDs are all you get for a display. Around back are a pair of speaker terminals comprising 4 mm binding posts, able to accept banana plugs, bare wire or spades. The six inputs are on unbalanced RCA jacks, with with a switch accompanying the AUX1 input to toggle the HT function.

M2si Blk Rear

This allows the M2si to power the front channels of a home theatre setup by providing a direct feed to its power amplifier from the preamp outputs of a home theatre receiver, giving the receiver control over the system volume. If this input is to be used with a standard line-level source it is essential that this switch be in the correct mode (right when looking at the back) or the amplifier will be run at maximum volume.

The tape input is not a traditional tape monitor function, rather an input like any other which just happens to have an associated line-level output. It’s still a welcome feature to find on a modern integrated, many of which are sadly omitting line-level outputs. Power is via a standard C13 IEC socket.

The Remote

The remote feels a little plasticky and dated, but replicates the functions available on the front panels of both the amp and CD player as well as a few additional functions inaccessible via the units themselves. of these, the only function applicable to the amp is a mute function. The remote feels good in the hand if a little lightweight and is logically arranged for the most part. Both components use the Philips RC5 code standard, and as such can be controlled by other compliant remotes.

Sound

The first thing I noticed on powering up the M2si was the low end. A relatively low damping factor of 36 means the M2si lacks the bottom end control of some rivals, but it makes up for it by putting that heavy supply of current to good use. The low end is deep and authoritative. Musical Fidelity have always had a tendency to produce huge muscular amps capable of demonstrating unflappable composure, even at high levels with demanding source material and driving a demanding load. While the M2si doesn’t quite possess the grunt of its bigger siblings, it has the same air of confidence and can unleash thunderous quantities of low end that is quite unusual for an amp of this price and rated power. With relatively high amounts of gain on tap, it only takes a nudge of the volume knob to get sensitive speakers rocking. And the M2si can get plenty loud with a more demanding load while showing no signs of strain or distortion.

Low end aside, the sound remains pleasingly neutral across the frequency spectrum with a slight tuning towards pace and excitement rather than absolute accuracy. The sound you’ll get from the M2si depends largely on your speakers and room, rather than the character of the amp itself. There’s plenty of detail and noise levels are low, with background noise only becoming evident at the top of the volume scale which it is highly unlikely you will ever reach. Detail is excellent at the top end and through the mids, and respectable at the low end though it does become a bit vague and blurred especially if you’re pushing larger drivers.

Summary

M2si Slv Front

The review sample of the M2si was well used, and having continuously pushed the sample hard over a number of weeks I have experienced no reliability issues. Based primarily on my experience with the A1, and having fixed a few musical fidelity products over the years, I did have questions as to their reliability. But after seeing the quality of the newest products myself, they are a vast improvement inside and out and I am confident that any such issues are firmly in the past.

I’ve thoroughly enjoyed spending time with this Musical Fidelity pairing. The M2si is a fine demonstration of what a reformed brand can produce from the get-go. Modern manufacturing, fresh engineering expertise and no doubt some considerable investment have produced a fine pairing indeed. Highly recommended.


About Ashley

I founded Audio Appraisal a few years ago and continue to regularly update it with fresh content. An avid vinyl collector and coffee addict, I can often be found at a workbench tinkering with a faulty electronic device, tweaking a turntable to extract the last bit of detail from those tiny grooves in the plastic stuff, or relaxing in front of the hi-fi with a good album. A musician, occasional producer and sound engineer, other hobbies include software programming, web development, long walks and occasional DIY. Follow @ashleycox2

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