






🎶 Elevate your audio game with vintage warmth and modern versatility!
The Fosi Audio MC331 is a hybrid tube integrated amplifier featuring a built-in DAC, delivering 105W per channel through 2 channels. It supports multiple inputs including Bluetooth, USB, optical, coaxial, and RCA, making it compatible with a wide range of audio sources. Its vintage aesthetic is enhanced by 5654W vacuum tubes and a real-time VU meter, while user-friendly features like remote-controlled bass/treble adjustment and replaceable tubes allow personalized sound customization. Compact yet powerful, it’s designed for audiophiles seeking warm, detailed sound with flexible connectivity in a stylish package.















| ASIN | B0DM1VLXHN |
| Best Sellers Rank | #18,808 in Electronics ( See Top 100 in Electronics ) #14 in Hi-Fi Amplifiers |
| Brand | Fosi Audio |
| Brand Name | Fosi Audio |
| Country of Origin | China |
| Customer Reviews | 4.3 out of 5 stars 327 Reviews |
| Global Trade Identification Number | 00466597167685 |
| Importer Contact Information | [email protected] |
| Included Components | MC331;Bluetooth Antenna;Vacuum Tube*2;Tube Cover*2; 24V4.5A Power Adapter;Remote |
| Item Dimensions | 15.1 x 13.5 x 5 Centimeters |
| Item Type Name | Amplifier |
| Item Weight | 4.2 Pounds |
| Item dimensions L x W x H | 15.1 x 13.5 x 5 Centimeters |
| Manufacturer | Fosi Audio |
| Material Type | Glass |
| Model Number | MC331 |
| Mounting Type | Surface Mount |
| Number of Channels | 2 |
| Output Power | 105 Watts |
| Package Type Name | Box |
| Packer Contact Information | [email protected] |
| Specification Met | General Performance Specifications |
| UPC | 466597167685 |
| Voltage | 110 Volts (AC) |
K**B
Amazing Sound, Great Looks
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.
N**M
Just only one word to explain it - Fantabulous!!!
When I ordered this Integrated Amplifier, I guess I was the 1st person to Order as there were no reviews found. Meanwhile, when this product was shipped, I got to see a review with only 3 Star stating this Amp cannot be connected to a SubWoofer and that made me to feel skeptical, because my main requirement is to use this Amp for my Home PC with a 2.1 setup. Despite this low rating I decided to wait until the Amplifier gets delivered and hence waited patiently. And the day arrived, the first thing that I did was I connected this to my PC and tested all the inputs paired with my Pioneer Vintage Bookshelf speakers along with an Active Subwoofer wherein I connected the subwoofer to its LFE input. Initially, I was shocked to notice that my Subwoofer was silent and there was no BASS - you know I am a BASS lover, I enjoy songs and videos mostly for the deep BASS effects. However, I didn't loose my hope - I have multiple subwoofers, and most of them are custom made with Plate Amplifiers and luckily all my subwoofers are equipped with multiple inputs (RCA Line In, LFE and the Speaker In/Out). In my 2nd attempt to test the Sub I connected the Pre-out from this Amplifier to the 'Line-in' Input of my subwoofer - Oh Man it was a WoW Moment - It worked!! and what a deep bass it was really awesome. For those who says this cannot be connected to a Subwoofer, please note the 'Pre-Out' from this Amplifier is not throwing out any LFE signals, but a 'Stereo Output', which can be connected to another Stereo Amp to power Speaker-B or to an Active Subwoofer that has 'Line-In' RCA Port. At 100Hz this 'Pre-Out' works well with my Subwoofer and there are no flaws, but it might work with different Hz with other brand Subwoofers. I am not using this Integrated Amp with any Headphones, but with my Creative Sound Blaster X4, which supports multiple sampling rates. Pros: 1. All inputs are working fine, especially the Bluetooth is excellent. 2. It remembers the last used input and selects it when the Amp is turned on. 3. Highs and Mids are very clear, but for the Low Frequencies either use a nice Pair of bookshelf speakers or connect a Subwoofer. 4. It comes with a compact remote which is not the case in all the brands at this price range. 5. It looks very elegant and I love the 'Volume Unit Meter', it makes to feel it Vintage. 6. No distortions were observed even at high volume; thanks to the VU-Meter that helps to monitor the db level. 7. The Volume control also attenuates the 'Pre-Out' level, which is not found in all the Amplifiers and I have seen few amplifiers that controls only the Stereo and the Subwoofer works even there is no output from the Speakers. Cons: 1. There is no ventilation provided for the heat to dissipate like other models in this Brand. 2. There is no option to dim the 'VU-Meter' light, which glows very bright. 3. Would be great if the input power supply is given as 240V, instead of an external step-down Power Adaptor that limits the Wattage per Channel. 4. Should have included a HDMI port with ARC (saying this because it has a wonderful DAC inside). 5. Option for connecting a Passive Subwoofer isn't available, would be great if included. 6. Installing the Tubes was quite hard and little risky as there is chance for breaking - they should have installed it and modified the Packaging Box so that it becomes a plug and play device without any risks while doing the initial setup. 7. There are no indications on the volume level - there is no min/max level set in the Master Volume and hence I am setting the PC Volume to the minimum to avoid any damage to the connected speakers. Also there is no MUTE button included in the Amplifier. Despite having these much cons, I have rated this as 5 Stars because there is no option to mark it as 4.5 Overall experience is good and it exceeded my expectations that makes me to give this rating!!! I hope the readers found my review helpful. Thank You.
S**S
Why this product is frequently returned. Bcoz read 👇
The tube amplifier produces a warmth sound signature where mid tones (vocals) are clear, sharp and upfront, base feels muddy even when we increase the bass knob there is no difference in tune. Functionality (treble and bass knob functionality is not that good won't vary that much),the base is muddy, treble is rolled off ( less sharp more pleasent type) Most of peoples like punchier bass, great vocals and sharp treble which fosi audio mc 331 doesn't provide hence everyone might return this. Who can keep this: those who love genre: jazz, blues, classical. ( Not for rap/hip hop) Ratings: Build quality: 5/5 Looks: 4/5 classy retro touch (the yellowish light in vu meter is high) Sound signature: ?/5 depends upon your taste, can be tuned if you vaccum tubes are available. Russian voskhod tubes are matched for hip-hop/rap genre. Connectivity: 4/5 bunch of inputs but no input for u-disk(pendrive)
A**N
Best budget PreAmp Tube based Amplifier especially for Windows PC users
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.
A**R
Awesome product, small yet powerful all in one!
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.
S**R
Small but powerful and decent amplifier
Small but powerful and decent amplifier - Nice sound translation. Good stereo image, warm sound quality. Decent looks and feel factor. Enhances feel of living room.
R**I
Good Product Based on Price
I have 2 passive speakers from Somy which was placed in store room for quit a long time. As a audiophile I always wanted the Desktop DAC, this product fulfill all the needs. It’s have headphones jack which is compatible with Dolby Atmos. Sound quality is good and Flat! Kindly do not expect bass/thumb on your speakers as this is designed for bookshelf speakers which usually have mid high frequency. I’m liking this product.
M**I
FOSI MC331 - Absolutely Worth It – A Little Beast of an Amp!
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. 💯💯
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