Review of the Fosi Audio MC351

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Review of the Fosi Audio MC351 - Fosi Audio

Written by Richard Hilton

This review is being written by myself after applying to be part of the Fosi Audio tester programme. For those that don’t know how this works, I applied for a couple of months ago since I am simply interested in trying out new technology and was permitted to take part. The unit I’m testing was provided to me by Fosi Audio with the simple expectation that I write a review “to provide detailed insights and opinions on the product and share you true experience and unbiased thoughts”. To be completely transparent, I have no links to Fosi Audio, I don’t own any of their products, and I’m not being paid anything for this review. I’m not even sure if they’ll ask for this unit back or not, so this review is certainly not being written on the basis that I get to keep the device. Anything I’ve written here is my own honest opinion and represents thoughts that I’ve also given back to Fosi Audio.

So for the review itself, well before I get to the MC351, I want to mention the excellent level of communications from the Fosi Audio staff that I’ve dealt with. Everything has been really well explained and all of my questions have been answered extremely well and incredibly fast compared to most companies. It was really refreshing. Obviously I haven’t had to call upon their after sales support as nothing went wrong with the device whilst I had it, but if my experience mirrors the level of professionalism with their support teams it certainly gives me confidence that I won’t be without help should things go wrong.

Ok, so for the device itself, well it came in a rather strange looking, off-brand box. Nothing like the corporate image being portrayed on the Fosi Audio website or in line with the colours of the units themselves. It’s a complete non-issue for me, but it did seem a little odd. Perhaps these test units are packaged using older boxes. What was less good however was the fact that the box was only wrapped in a thin layer of bubble-wrap for transit and hence all of the corners and edges had been crushed which was a concern when the unit first arrived. Fortunately, the inside of the box is extremely well padded and the device itself is well protected from any knocks it could have received enroute. It was a little strange given how good the rest of the experience had been (and would continue to be) that something as simple as protecting the box/unit from damage was so inadequate. It’s pretty hard to imagine how this box wouldn’t have suffered some damage on its way to Sweden from China, so why not protect it better?

Once the box had been opened up, what presents itself is all of the things that one would hope to see. The MC351 unit of course, an optical cable, a USB-C to USB-A cable, the 32V power supply, a bluetooth aerial and of course the user manual. All neatly presented. It didn’t take long to assemble everything together and to mate the unit with a pair of Eltax Liberty 3+ speakers that I’ve really enjoyed listing to over the 20 years or so. They’re certainly not luxury items but the ability to express pretty deep bass and allow a crisp and clear top end allows them to be used for a wide range of different musical styles.

So, what exactly is the MC351? Well, it’s Fosi Audio’s soon-to-be released all-in 2-channel amplifier powered by the Texas Instruments TPA3255 chip. For those that know the Fosi range, I view this as the natural evolution of the MC101 or BT20A Pro. Indeed, it seems to blend various aspects of those two models and add some extra functionality on top. The result of this is a good looking device that can pretty much do everything that a typical home user would want and all from a single compact unit! For inputs there are RCA, optical, USB, coaxial and Bluetooth 5.3 options, whereas for outputs there are the usual 2-channel speaker binding posts, a pair of binding posts for a passive subwoofer as well as a pre-out option for those that want to use an active subwoofer, active speakers or an additional amplifier. It doesn’t have the XLR-in from the ZA3 amplifier, but that’s a rather different device to this one and I suspect that most normal home users won’t really care about the lack of that functionality.

On the front of the device, it proves to be a great looking device and something that friends and family members have all commented on. There is the now ubiquitous orange on/off volume knob, bass and treble knobs and a simple button to scroll through the various inputs. Lastly there is a VDU on the left-hand side. The unit itself appears to take the same form factor as the other models but this is perhaps a touch taller, at least to my eye. It’s a very pleasingly compact with good proportions. Something that can be shown as a feature of a room, instead of needing to be hidden away like so many other electrical devices. It comes down to individual taste of course, but personally I love the design language that Fosi Audio used in its latest products. There’s just something good about the orange and black combination, the soft warm lighting of the VDU units and the obvious presence of the vacuum tubes in some of their products. For many people this won’t matter at all as it’s solely about the quality of the sound, but in my opinion there’s no reason why you shouldn’t try to have both. At the end of the day, I want to listen to good quality sound reproduction but also enjoy the actual music, and not just listen for imperceivable differences between one component and another. I want to actually enjoy the whole experience, and how the unit looks, how the knobs feel etc all contribute to this. I have no idea if Fosi Audio have thought about their products in this way or not, but in my opinion they are doing a great job of offering that all-round good experience with their products.

So how does it sound, and does the actual experience of using the MC351 reward as much as the good looks and spec sheet promise? The short answer is “yes”. That’s not to say that everything is perfect (more on that later), but I can honestly say that two weeks that I’ve been testing this device has been incredibly enjoyable and I wouldn’t hesitate to recommend this device and for me and my use-cases (listening to music in my home office and using it as an amplifier for my TV in the main lounge area) it has excelled.

My first test and also my primary usage is to stream audio via bluetooth. Connecting to the MC351 was really simple and extremely fast - notably faster than other devices for some reason! It’s simply a case of turning the orange volume control to switch the unit on (something that I really appreciate as I hate devices with a push-on approach where you don’t know what volume is about to come blasting out of the speakers!!), then simply searching for the device on your phone/laptop etc. That’s it. Nice and simple.

With the treble and bass set to 12 o’clock, the first thing I immediately noticed on playback was how balanced the sound was. Really pleasant. I tried a playlist containing a variety of musical styles to get a good feel to what the MC351 is all about. Tracks ranged from the classic “Jazz at the Pawnshop”, through to acoustic guitar laden folk tracks, more rock-based tracks from Muse and Metallica, blues from Gary Clark Jr, and on to Beastie Boys and Avicii for something livelier. In every case the sound was detailed and didn’t disappoint.
Overall, I felt like a small bump in both the bass and the treble would finesse the sound sightly (this might be more to do with my speakers than the amp, it’s hard to tell). This leads me to perhaps the two things that I didn’t like so much about the MC351. Firstly, is the sensitivity of the treble and bass controls. A tiny amount of movement of either of these results has an enormous impact on the sound, which make it hard to truly dial in the perfect sound. Lots of tweaking, stepping back to listen then going back and undoing some of what you’ve just changed etc etc etc… It’s fair to say that now I’ve got it set up I’ve not felt the need to adjust anything since then so for a one-time only thing I guess it’s forgivable, but I’m not sure I understand why it needs to be like this. Why not just make turning these knobs more progressive and allow for finer tuning of the sound, given that more than a small tweak influences things so much that no one is likely to want to push the sound that hard.

Related to this is the second thing that I found somewhat inexplicable, and that’s the fact that the treble knob is on the left and the bass knob on the right. Maybe others are used to this configuration but for me this is really counter-intuitive and many times after setting one parameter as I wanted it, I would listen for the other, go to alter it and find myself turning the wrong knob and screwing up the previous setting. Given the sensitivity of the controls this made the whole thing really frustrating. Ultimately, it’s a really minor, albeit annoying issue and now I’ve got things set as I like them I don’t feel the need to change things too often, if at all. Whilst I think about it there is one more thing that I’d like to raise here, and that’s the lack of a clear marker on the knobs that show their position. There is a tiny little indent but it’s almost impossible to see unless the light hits it in just the right way. A tiny white (or orange) dot would make all the difference.

If I was to be picky, given that this is a device that’s trying to be an all-in-one amplifier, the lack of a balance control feels like a bit of an obvious missing feature. The reality of people homes are that most people don’t have dedicated rooms that are perfected for acoustic properties. Speakers can’t always be put in the ideal places and the presence of furniture, windows etc all change the way that the different speakers contribute to what you hear. My experience is that a balance control is a good way to restore some of the inherent biases that can slip in. I’m not sure how this could be squeezed into the front of the unit though without disturbing the aesthetics, but perhaps it could have been added on the rear of the unit, since it’s unlikely to be changed regularly? Just a thought. The VDU meter is almost the complete opposite, I genuinely have no idea how this is useful (as opposed to having separate ones for left and right channels), however I love it being there! Having it lit up in a dimly lit room and just seeing that needle bounce around is an absolutely joy.

So those represent the weaker side of the MC351 from my point of view, and I’m sure that most people would say that these are trivial issues, and they would be right. This is therefore really a testimony for how good the sound is from this unit and how impressed I am with it overall. The quality is excellent, and maintains clarity as the volume rises all the way up to maximum. Regarding the volume, the devices rating is stated as 2x 165W RMS
+350W at 4-ohms. I don’t have any way of testing if that’s accurate of not, but what I can say is that with the provided 32V power supply the MC351 is louder than I can ever imagine using day-to-day in my ~6m x 6m rooms. At full volume it’s not uncomfortable though, perhaps what you might want for a lively party? But I can imagine that for some people this won’t be enough. Fosi Audio to sell a 48V power supply if you do need more. With the 32V power supply it’s all I will ever need and I suspect that this is true for most people.

Overall, I have thoroughly enjoyed testing out the MC351 and I can honestly say that it’s almost the perfect device to fit into my lifestyle and what I want from a hifi system. Is it the perfect device for everyone? Of course not, and for many hifi fanatics they love the challenge of optimising every single component and having total control over everything, but I feel that that’s not the point of the MC351. This is a highly flexible amplifier that delivers high quality sound in a simple to use and attractive package. That means it ticks a lot of boxes for a lot of people.
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