MC331 Tube Integrated Amplifier with DAC, 2 Channel Home Audio Stereo Power Amp for HiFi Bookshelf Speakers/3.5mm Headphones, Vintage VU Meter Preamp with Bluetooth and USB/Opt/Coax/RCA

A must have amplifier for anyone who wants to enjoy clean, warm & colorful music. Very good build quality. It has thick aluminium body & the tubes have an outer glass protection which protects it from accidental touch which may loosen it or can very minutely burn our hands as it can become hot if keep it ON continuously for a day or two. Pros:- 1)It is a tube (PreAmp) based amplifier which gives clean, warm & colorful music. 2)It is multipurpose amplifier as we can connect a headphone, passive speakers & active speakers with it. We can also add a sub-woofer using the pre-out port making it a 2.1 speaker system amplifier. 3)It has multiple inputs like USB-C, RCA, COAX & Optical. If you want to connect passive speakers, use the BANANA port & if you want to connect an active speaker, then RCA cable of the speakers which have a single 3.5mm jack should be connected to pre-out port. Cons:- 1) Every time you switch it off from the mains, it will forget the last volume setting. Well this is actually not a Con but a safety system to ensure that if someone has set the volume to very high, next time when it is powered ON, it may damage the passive speakers. 2)Even though the manual says that USB-C supports 24bit 96Hz, on PC you will only get 16bit 48Hz due to its chip's plug & play limitations. 3)Some people said it's bass knob is useless & there is not enough bass for Rap-Hiphop but on my Windows PC setup, I have a free software Fxsound installed which inhances music. I am getting superb bass & treble on my headphones since I can control it through both Fxsound+Fosi bass treble knob. And is join it with my Edifier R1855DB active speakers, I get the extra bass treble control given on its back.

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. 💯💯

FIRST REVIEW [28 DEC 2024] [2 stars]: I’ve set this up at home on my desk, for casual music playback. I’ve connected a pair of Philips bookshelf speakers for two-channel playback. I primarily use the USB-C port on my MacBook Pro M1 Pro (Model Number: MKGP3HN/A) to connect the MC331. And occasionally use my iPhone 15 to play music via Bluetooth. When I connect the MC331 via the headphone jack, I can choose between several options up to 24-bit 96kHz formats for playback in the Midi setup app. But when I connect it via a USB-C cable, the options are limited to 48kHz and 16-bit. (See attached screenshot) Despite this discrepancy, the user manual states that the device can support up to 24-bit/96kHz playback over USB. (See attached screenshot) I purchased this device specifically for its advertised audio capabilities, and the fact that the amplifier is not functioning as advertised is unacceptable. Reached out to the OEM and they washed off hands saying the manual is incorrect. UPDATED REVIEW [15 JAN 2025] [4 Stars]: After using the amp for a month, here is my updated review. I have tried all other inputs and tested the features of the device and they perform on par with the claims. The 3.5mm and Optical inputs works very well and the sound quality is pretty good. Bluetooth range is also reasonable. Apart fromt the above mentioned shortcoming, I didn't find any other issues. And comparing to other features, I can overlook the limited sampling rate for USB input. And I think the feedback can be changed to 4 stars.

The MC331 Tube Integrated Amplifier is a fantastic choice for music enthusiasts, especially those who appreciate vocal-driven tracks. This amplifier delivers a warm, textured sound signature that enhances the clarity and richness of vocals, making them feel natural and soothing. Whether you're listening to your favorite singers or enjoying acoustic sessions, the MC331 elevates the listening experience with its gentle yet detailed tonal delivery. The built-in DAC ensures crisp and accurate audio reproduction, perfectly complementing its tube amplifier's warm characteristics. Its two-channel stereo setup provides a balanced soundstage that feels immersive without overwhelming bass or treble. In terms of value for money, the MC331 stands out. Its combination of premium sound quality, solid build, and elegant design makes it a must-try for audiophiles on a budget. If you're someone who enjoys vocal-centric music or just appreciates refined audio performance, this amplifier is worth the investment.

This is an awesome product at this price point. but beaware of the package contents. It is highly recommend to make an unboxing video. i received 5725W vaccum tubes instead of 5654W these two have totally different characteristics for audio modulation. This is a very good quality product. Small yet a powerful all in one. Bluetooth connects seemlessly, RCA, Coxial, Optical ports all work smoothly. Headphones sound altogether different, in a good way. It Comes with a good quality power brick and a remote controller. Adds warmth to the audio sound and astethics to the setup with warmly glowing Vaccum Tubes and analog VU meter.

I got a used product. The original seal was broken and the box was retaped. It had remnants of what probably was old packaging returned from another customer. This came in the same box as another order which had a Open Box Inspection and I showed this to the Amazon delivery associate right then and there. However, the deliver associate asked me to initiate a return, since the Open Box inspection wasn't there for this item. After I had this experience, I saw the reviewers of many other users are also facing this kind of issues with Fosi Audio. This definitely kills the user trust in the brand. For an item costing over Rs.15000, it is not acceptable to send used / returned / open box products.

Best audiophile class D amplifier.not for those who love loud and punchy bass.its crystal clear sound.nice to hear musical notes and melodies

A well made product - build and construction. Audio output is sufficient for me - using it in as monitor setup for close proximity hearing. No issues with of auto switch off. The Tube mellowness is there to hear. Bluetooth connection is smooth and without glitches. However I feel cheated as the product is rated for 24 x 96 kHz - even the manual says so but the product is able to play only 16 x 44 kHz. Writing to Fosi about the issue got me an apology saying they will update their specifications !! Not acceptable at all and such casualness will not get them customers. If i were to buy again i would go for Ayima T9 Pro..

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.

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.

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