Fosi Audio 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

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.

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.

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)

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.

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.

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.

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.

Nice compact amplifier powered my loud speakers well. Most horrible Bluetooth range, which would fail even if a small obstruction occurs in the line. Both Fosi Amps I bought had horrible Bluetooth range.