The Musical Fidelity M5si Integrated Amplifier Review

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The Musical Fidelity M5si is a stereo integrated amplifier that sits smack dab in the middle of musical fidelity’s M series of products. It packs quite a bit of power at 150 watts per channel into eight ohms and it has an internal dual mono block configuration. 

It also has a built in moving magnet preamp which you can use for turntables, it has a preamp output, and it also has a home theatre pass through though, admittedly, a home theatre pass through is shared among one of its four analogue inputs. Still, it has an asynchronous USB input and when you add it all up, it makes for a pretty compelling integrated amplifier option. 


These Fidelity’s M series of integrated amplifiers share largely the same physical appearance so telling the M5si apart from the others can be difficult. Still, I absolutely love the way the M series products look, especially in their white ceramic like finish. Now you’re free to disagree but I think it is absolutely the bee’s knees, and I just love how minimal and unassuming yet high end the M fives looks and feels; because this thing is built like a tank, and if it weren’t for the included plastic remote, there would be absolutely nothing about the M5si that would otherwise alert you to its relative high end affordability.

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But let’s talk about that remote control for a brief second, it’s crap. It’s the same remote that you would get whether you buy an M2 or an M8xi which is inexcusable. It has the same wonky layout, silly buttons, poor responsiveness and honestly it just has no business being paired to an amplifier of the M5si’s calibre. 

Now pay attention because we have actually paired this particular integrated amplifier with a lot of different products cuz we’ve had it for a little while. Speakers included the heresy Mark fours the La Scalas, Q Acoustics Concept 300 bookshelves, as well as the Wharfedale Denton 85. We streamed music from Tidal in high resolution and we have even managed to watch television and movies with it by connecting it to our LG 8k Smart TV using an HDMI to analogue audio extractor. 


We have used three different turntables with this amp; starting with the Audio Technica LP 140XP, the Fluance rt 85, and Andover audio’s new spin deck. Earlier I said that you sometimes have to walk your way into a bull’s eye when it comes to selecting the right gear for you in your system. And for us this journey started with the musical fidelity M8xi, which is arguably the brand’s flagship. I absolutely loved that amplifier and I still think about it to this day. It was that special of a product at least for me, it checked all of the boxes, save for one. 

It is just huge, heavy and for someone like me that has to change out audio gear rather frequently, sometimes daily, the act of having to deadlift that sucker just wasn’t going to be sustainable. The M8xi led us to the M three si which is quite the pendulum swing I know; to go from like flagship to say entry level, but I’m really glad that we went down stream because it showcases just how much performance you get in the M3si. 

I’m not saying the two amps are remotely comparable but you can definitely hear a lineage and I seriously thought about hanging on to the M three si as sort of a budget to mid Hifi reference but we only have so much room in this house to hang on to gear and I was concerned that the M three si may not be the the best for every loudspeaker in terms of power. 

So the search continued. And that brings me to the five for roughly $500 more, you do get almost double the power of the M three but you retain all of the M series looks and functionality.

But with great power comes even greater responsibility. So, how does the M fives measure up? Let me just get this out of the way, I don’t think it’s possible for someone to be disappointed in the sound quality of a musical fidelity integrated amplifier at any level. What becomes difficult is the sheer fact that there’s so many integrators with which to choose from, it’s kind of like the Cheesecake Factory menu; by the time you get to page four, you forgot what was on page one and the next thing you know, you’ve been in your booth for four hours you’ve only ordered a drink and you’re starving.  Then you end up just getting like the chicken fingers because you can’t think of anything else.

And that’s how many options you have with musical fidelity and they’re not that different; in fact ,they really only differ in terms of their power output and internal amplifier construction but these are two things that matter. The M5si sound is one of absolute ease and effortlessness. It’s not wholly transparent, or colourless but its sound signature is very alluring, at least to me.

I wouldn’t classify it as neutral; there is a mild emphasis on the mid bass and bass regions and as a result, I think that you’re just going to find that you get the sense for or feel just a little bit more bass, compared to comparable amplifiers, and this was more than evident when we paired it with our Klipsch heresy Mkiv which on their own, don’t always manage to hit the lowest notes and yet, with the M5si in the mix, they did seem to pack on a few extra pounds.

Thankfully that bit of added bass depth does not come at the expense of speed in detail which is something that I’ve come to expect from musical fidelity. The texture it just brings out of instruments like drum kits and bass guitars; it’s just one of the things that I respond to the most and it makes you want to just keep listening to rock and hiphop.

It does that type of music justice, and then you get to the mid range which because of the M five s highs, slight emphasis on bass and midbass do feel more weighty and grounded. Vocals are just locked in space and have a real sense of presence to them that makes it very difficult to go without once you’ve experienced this internally. The human voice sounds absolutely right through this integrated amp; like you’re listening to it unfiltered. Our Uniti atom has great mid range but it does smooth over some of the detail and inflections which makes the mid range very pleasing but the M5si by comparison just feels more real.

The same is true of instruments that occupy the mid range space. Take for instance an acoustic guitar, that same “organic real” quality is present. Apparently M5si with high efficiency loudspeakers like our heresy Mk4’s, be prepared to hear subtle cues and the music like never before because this amp just seems to get in there and shine a light on everything. But this is also kind of the amplifiers Achilles heel as we found out when watching streaming television; because not every signal or stream is going to be the utmost quality and when you feed this amplifier a signal such as this, you need to be prepared to hear things like digital compression, artefacts limiters, all of that stuff in its full glory because it is just not going to suddenly change its characteristics and gloss over all of that and when that happens.

You’re going to get a real sense for just how veiled some amplifiers are by comparison. Which brings us to the high frequencies, the high frequencies have a real sense of scale in direct comparison to other amplifiers. For example, a lot of other amplifiers managed to get the metallic ring correctly. They may even give you that dynamic impact of like sticks on metal but what they lack is scale. 

What the M five brings to the party is that sense of scale so you get the dynamic impact, but you also get a sense of the scale of the symbol itself. So you’re getting scale, air detailed decay, all of that stuff but like the mid range, their high frequencies aren’t going to gloss over a poor recording and they’re not going to hide things like sibilance.

So I wouldn’t classify its high frequency performance as forward or fatiguing, but you need to know that it’s not going to editorialise, either. The soundstage is not unnaturally wide or deep; this amp definitely puts an emphasis on detail and composure rather than trying to win you over with just size, but you should know that the soundstage does scale as you turn things up.

And speaking of scale, the dynamic prowess of this amplifier, it’s like its power knows no limits. In fact in terms of dynamics, it’s second only to the M8xi, which is saying something, because that means the M five slaps and listening to drum solos like the beginning of Dave Matthews band’s “ say good bye” sounds positively epic. Not to mention vividly real, especially through our Klipsch loudspeakers.

I just sit on our couch and just shake my head because the M5si really does have it all; it has the tonality, the detail, the scale and the dynamics. In a perfect world, I think the M five would likely have a better remote, and it would probably have a better or more robust DAC as it relates to digital connectivity. 

I like the M three si and have no problems recommending that amp to anyone, especially if you’re on the market for an amplifier of that calibre but if you can save your pennies and stretch your budget, the M five is an upgrade in more ways than one. Now, according to musical fidelity, the M fives technical performance is about equal to that of the six and if I can save $800, I’m going to. But what makes this six unique is it has a little bit more of a robust dual mono block. You know, architecture, inside, not to mention, it’s balanced. 


It’s a bit of a toss up which of these two amplifiers I prefer as both appeal to me for radically different reasons. The Yamaha has that vintage vibe that flair and that you know I like so much. It is a little bit more of a livelier design which can be a good thing but I just keep coming back to the M5si and i think i do because of that mid range, weight, texture; there is just something about that I can’t live without.

Are you in the market for an integrated hi fi system or do you just need an integrated amplifier?

I absolutely love the M5si, which no doubt is why we are making it part of our permanent collection, it gets very close to matching the performance benchmarks set by the M8xi but in a far more manageable, physical package. 

Now I understand that it is not cheap by everyone’s standards but I do consider it a relative bargain given where it falls in the marketplace. Plus its build quality inspires a lot of confidence that I’m going to be able to enjoy this amplifier for years to come and that makes it an investment. So when everything is said and done, it has turned out or ended up becoming the best M series amplifier for me and my needs. And if your needs align with mine, it may just be the best amplifier for you as well.

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