- MC331 Tube Amplifier with DAC, Bluetooth Stereo Amp for Speakers

LOOKS amazing! SOUNDS great!! Remote SUCKS! ha ha ha! but then again, I am a bit impatient... This little amp is a joy to listen to! and play with! and look at! It looks so good: small, the VU meter moves a lot, the light is soft, it is a joy to look at, very elegant on the mantle. Sound is very nice; warm, detailed, voices come in as if the singer is there (listen to Norah Jones - Come Away With Me - 24bit/192kHz - Qobuz.com). I hooked up (from my Samsung S22 with Qobuz) an external DAC to it (SHANLING UA4, Moondrop Echo-B, or FiiO KA13 dongle amp) and my speakers Magnat 503's (which are very efficient at ~91) and got very good sound. It can get loud (loud enough to make the dog next door bark, and that furious little thing is ~100 ft away). But the sound quality stays very good and even at loud levels, very loud levels. I have other setups that are Class AB (Arcam SA10 with FiiO K13 R2R, and fed by the WiiM Pro AirPlay 2 Receiver, again via LAN cable and Qobuz). The difference is very minimal and I can tell only because the FiiO K13 R2R architecture leaves a mark on your ears/brain (that thing is so AWESOME!!! of all the entry-level DAC's I reviewed that one I kept. It is better, in my opinion, than ~$2k DAC's. Actually of all the DAC's I tested this one (FiiO K13 R2R) is the best sounding. You'll love Voila by Andre Rieu and Emma). Anyways!! I am getting this little amp for my sister for Christmas. She will not mind the remote latency at all, and she will be so happy at the way it looks. It looks very good, one of the most well designed aesthetics in the audio world. I am getting the "1Mii B06Ultra Bluetooth 5.2 Receiver" for her so she can listen to this thing via LDAC Bluetooth from her phone, as this little amp does not come with any worthwhile codec's. Back to the Fosi Audio MC331 - The REMOTE SUCKS: the remote takes two seconds to recognize you pressed the volume button on it (up or down), if and when it decides to recognize it. And you have to point it directly at the amp, the IR will not bounce off stuff like it does with other remotes. ALL the buttons have a darn-awful latency to them, even the selector. It can get infuriating after a while. I was working on a spreadsheet and wanted the sound just a little lower and instinctively picked up the remote and pressed the volume button, but it took forever to register so I had to take my mind off what I was working on to focus on "is this thing working!!??" It pisses you off after a while. And yes, some of the sound disappeared when I turned it very low (almost silent); and no, "that is expected, dufus!" because I get that, but on the other systems at that very low level ALL the sound comes across-the-board at very low volume, not just some of it. Highly recommended! Just fix the remote Fosi!! :-) :-) another little thing... it will not work with a higher-end power supply. I tried another Fosi power supply on it and it will not even turn on, so you are stuck with the power supply it comes with. Not a problem, but in case you were wondering "what if..." you added a better power supply?? No, it will not work. You are stuck with the 24V it comes with.

I really like this amplifier! The combination of the vintage-style tubes and modern design looks fantastic, and it adds a unique touch to my audio setup. More importantly, it sounds great! The audio is clear, detailed, and enjoyable to listen to, with a nice overall sound that makes music feel rich and engaging. I also love having the DAC and amplifier combined into one unit, which keeps my setup clean and simple without needing a bunch of separate components. Its compact size is another plus, making it easy to fit on a desk or entertainment center without taking up too much space. Between the sound quality, the classic tube aesthetic, and the modern connectivity, it’s a great little piece of audio equipment. Overall, I’m really happy with it and would recommend it to anyone looking to build a nice home audio setup without going overboard on equipment.

There are basically two categories of inexpensive audio equipment: "you get what you pay for" and "capable of embarrassing much more expensive equipment". I think Fosi has garnered the reputation at this point to run for president of the latter group. I love this amp. I'm a musician and high quality audio is important to me, so believe me when I say it sounds good. The warmth and quirks of the tubes is very audible. Play music through it before they're fully warmed up (and they do get quite warm) and the sound is harsh and lacking dynamic range. Give it a few minutes and the sound mellows out and the sound stage comes into its own. There's easily enough power to fill a room, and it's sounded full and detailed with every genre. I also really appreciate the style and build quality of this unit. Unlike many other products at this price point, the construction is entirely metal; and not foil-thin metal the flexes under minimal strain. It feels sturdy, thick, and has a decent weight. There's no plastic here (except for the shield on the vu meter and the protection tubes around the vacuum tubes, which I don't mind). Even the knobs on the front are metal, and feel very satisfying in the hand. The connections on the back are also solid, if a bit small and close together. I think banana plugs are pretty much a must on this unit, unless you want to spend 10 minutes "threading the needle". Out of the box, the tubes come separately and you attach them yourself, giving it a bit of a DIY feel. Maybe having to partially assemble the unit yourself heightens the emotional connection. It's not just plug-and-play; you actuay have to spend some time interacting with it before you can use it. The tubes are featured prominently, but the amp makes no obfuscation of the fact that it's a thoroughly modern piece of equipment. There's a minimalist aesthetic here that I appreciate, and it's pulled off much much better than the brands that try to go for a faux-vintage look. The volume knob is doubles as the input selector by pushing it and the power button by pushing and holding for a few seconds. Turning it on or off, either with the power button or the handy remote, the unit gives a satisfying click. The only other controls, the bass and treble knobs, are very functional. The dichromatic amber-on-black is visually pleasing, and the amber lighting around the tubes is actually tastefully done I think. Tubes naturally have a dim glow, but many units (especially cheap ones) feel the need to play this up by covering the tubes in LEDs that usually look tacky. Here, the subtle amber glow accentuates the tubes, I think, rather than obfuscates them. The VU meter is also just fun. I think that's about all I have to say. I'm gonna go back to listening now.

I really do like this unit. It’s pretty much exactly what I expected: inexpensive, small footprint, and decent sound. A couple of things to keep in mind, though. First, you must use the remote to turn it on — there’s no power switch on the unit itself. Second, it took me a little while to get it working with my PC, but once I adjusted a few settings (with a lot of help from AI), everything came together. The only real disappointment is the tubes. You can’t see any glow from them unless you look straight down into the chassis. Even in a completely dark room, the tubes are recessed so deeply that the glow isn’t visible from the front. It’s a small thing, but I was hoping for at least a little bit of that classic tube ambience.

I ordered this amp for my son, as he had recently come across some nice old passive speakers. I wanted something simple and cool and compact, and this device does not disappoint. The tubes give it a retro look and feel, and I think they sound great. The controls are simple but user friendly, and the remote is very handy. Bluetooth connection works great. The build is sturdy and high quality, on a device that cost less than a tank of gas in my work truck currently. Would highly recommend

I purchased the Fosi Audio MC331 tube amp as part of an upgrade for my home office/gaming setup. This is my second Fosi Audio product that I have purchased. I really like the options that I have for connecting my devices. I am using the optical port on my PC's motherboard to connect, a USB A to USB C cable to connect my PS5, and lastly, a 3.5mm to RCA to connect my work laptop to the amp. I even have the option to connect my phone via bluetooth to the unit. Set up was rather easy. You will need to install the vacuum tubes, the glass heat shields, and the bluetooth antenna. As with most tube driven devices, you will need to allow some time for the tubes to warm up before cranking up your music. The VU meter is a nice touch. It quite reminiscent of vintage stereo receivers and is cool to watch as your music plays. The lowing tubes also look cool. Sound wise, it's performs quite well. I have a pair of Polk Audio T15 speakers hook up to the amp. It has more than enough power to drive my speakers. The tone control knobs, while only controlling the treble/bass, work well. The volume knob is "clicky" which is unnecessary. The remote response is a little slow, and you need to point it straight at the IR sensor for it to work. The internal DAC gets the job done, but I wish the could handle higher end coding for UHD quality audio. Overall, I am quite happy with my purchase. It works great for the space it was intended to be in. I would recommend this product for someone that wants to start getting into hifi with out breaking the bank. This amp with speakers, speaker wire, banana plugs and cables, I'm in well under $300. Pros: Easy to use, comes with a remote, cool looks, plenty of power to push most bookshelf speakers. Cons: Volume know feels weird, the tubes it comes with work fine, but upgrading you tubes will bring this unit to life. Tubes need about a minute to reach operating temperatures.

This barely works as an amp, look up any forum on this and you'll see countless issues. The headphone jack is unusable due to how it delivers power. Its seemingly designed strictly for high volume output. If you put it at any reasonable listening volume (quieter) it cuts out constantly and has terrible buzzing background noise. Even powering 4 way tower speakers, it buzzes and cuts out. I have no idea what they expected you to connect to this for it to work properly. The visuals are all it has going for it, but even the VU meter is useless because no volume except ear splittingly loud even registers on the meter. Tried the USB, RCA and optical inputs with the same result on all. DO NOT BUY

A simple tube based power amplifier that has a Bluetooth receiver that can pair with up to 10 devices. It will only receive from one device at a time, so you need to turn off the Bluetooth device on are not trying to pair with when switching between Dec, but this is to be expected. I have used it with a Bluetooth enabled turntable, and a couple of iPhones. All worked as expected. I also tried a very inexpensive Bluetooth enabled pocket cassette player, and would not pair. So, your mileage may vary. Sound quality is decent, with pretty good bass. Ultimately this is determined largely by the speakers, so the better your speakers, the better the sound. It has a Bass and Treble control, which work, but obviously not as good as a multi channel equalizer. Build quality: Seems good. All the parts were provided and packed properly. I had no difficulty assembling the amplifier, which just involved plugging in the two tubes, screwing in the tube heat protectors, and connecting the cables. Power: The amplifier is rated at 105 watts per channel, into a 4 ohm load,, which is more than enough for any small to medium sized room. I noticed no distortion at any of the sounds levels I was using. The price: at $116 with a small running discount, this amplifier is easily worth the price. You get what you pay for I guess. Overall I am happy this little amplifier. Recommended!

The sound is good

Es el segundo equipo de Fosi que adquiero, el primero fue el Q6 y ahora este. Sin duda son excelentes ambos, el sonido de verdad es grandiosoEl MC331, es un amplificador con esa calidez que solo brindan los bulbos, realmente es mut recomendable esta marca, y sobretodo, sus costos, son en realidad muy accesible, comparados con las marcas de equipo de audio en el mercado.

Absolutely Worth It – A Little Beast of an Amp! I’ve had my Panasonic VK 550 speakers (8 ohms, 120W) for over 22 years now. With a full Hi-Fi setup and a newer 3-way speaker system, I was planning to retire them. But a friend suggested, “Why not hook them up to your PC using a small desktop amp like a Fosi or Aiyima?” I was skeptical at first — these are power-hungry speakers and I didn’t want to spend more money just to experiment. But after testing a similar setup using my friend’s Aiyima amp, I was completely blown away. I immediately ordered the Fosi MC331 — and let me tell you, I’m 200% satisfied! 🔥 Pros: • Vintage charm meets modern clarity • The sound is crystal clear, rich, and well-defined • Once the tubes warm up, the audio transforms — giving you that warm, musical, analog touch you just don’t get from solid-state amps • Despite its compact size, this amp is an absolute beast — effortlessly driving my old VK 550s This little tube amp has brought my vintage speakers back to life in the most beautiful way. If you’re on the fence — go for it. You won’t regret it. 💯💯

中華製と侮るなかれ、このコストながら多機能で音質は高次元なレベルで大満足です。

Excelente