Looks great, sounds even better!

I really loved the **Fosi Audio MC331**. I had always wanted a tube amplifier on my desk, and even though the tubes are small, they give it a very fun look and plenty of personality.

What surprised me most was the sound. For such a compact unit, it sounds very good, with a pleasant presentation and enough power to drive my **Monitor Audio RX6** without feeling out of place at all.

In my setup, the MC331 actually ended up feeling a little small physically on the desk, but performance-wise it delivers much more than its size would suggest. It is a very enjoyable little amplifier, easy to use, good sounding, and visually different from the usual desktop gear.

For anyone who has always wanted to try a tube-style amplifier without going into a large or complicated setup, the MC331 is a very fun option.

Glowing (unlike the tubes)
I love my amp, I even figured out the usbc connection (one day the optical) the only mild disappointment is the glow of the tubes… they simply don’t look bright

very impressive piece. quite a looker, tubes are awesome, tone controls are handy, easily pushes decent desktop speakers, easy to setup 2.1 and runs any iems to full advantage, love it, remote makes it versatile, footprint is minimal, not my first Fosi amp, totally not my last (mono power blocks next, watch out for coupons )

The charged arrived broken. The ligth turn on but Don’t genérate voltage. The amplifier sound it’s amazing

I will bought it again

A lot of music for the money. It´s conected to my computer and a pair pf monitor speakers Magnat S10B with 86 db and it plays with energy and control. For that price I´m stunned.

Compact unit with multiple inputs, I use optical for CD player, coaxial for streamer, USB for desktop, Bluetooth for iPhone, still have a RCA for extra...

This little unit surprised me. Have it matched with a pair of Sony CS5M2 Speakers. It ticked all the boxes, Bluetooth, Optical & RCA. Sounds great, the tubes give a nice warm sound with a little punch!

it looks like an superior developed Tube Enigma for the audiphyle which survived in the cold war

it sounds like a thunder

great

I changed my audio system from 40 years old pre-main AMP (marantz PM-94) to this MC331.
New technology is quite good even for elderly people like me.
The sound is quite natural and clear.
The usage is simple and easy with enough interface for any audio equipment and sound source.
I love this MC331 so much.

Aunque el tamaño es menor a lo que pensé, ésto se compensa con su calidad de sonido y versatilidad para la reproducción desde diferentes fuentes. Deben mejorar el embalaje, instalando desde la planta los bulbos. Gracias!

He comprado este equipo hace algunos meses, tuve un inconveniente al principio pero el equipo de fosi impecable atención post venta, destacable.
En cuanto al equipo cambie de válvulas por unas NOS GE 5654w y suena muy bien, mejora notablemente respecto de las stock .
Ecuación costo/beneficio es imbatible

Amazing sound for this size.give my b&w CM1 a New life !

I bought the Fosi amp to replace a vintage stereo I had hooked up to my Tv and DVD player that was having issues and not working regularly . The fosi amp costs almost as much as a professional cleaning and repair of the vintage stereo I mentioned. I Have only used it as a headphone amp, haven't attached passive speakers yet. Sound is pretty nice , tone adjustments are pretty responsive. It's nice to have something that will work reliably.

Amplifier audio quality is mid, at medium - high volumes suonds good and makes you hear all the details of the song, but at medium low volumes has some hiccups, the volumes jumps up and down, i hate that and you lose detail. The build is nice and sturdy, knobs feel great, remote is useful but the treble and bass setting are a bit useless. The amplifier tends to be a little hot after a while. When you listen at medium high volume is quite rich sounding and packs a good punch while retaining the details of the highs and the voices. I think it's mid because of the volume hiccups and inconsistency at medium - low volumes, it's a real problem, hope they will solve this in the future.

Easy to assemble (just putting tubes in), took longer for me to run my power to it haha. Bluetooth sounds great. Even made my cheap satellite speakers sound better.

Fosi Audio MC331 Tube Integrated Bluetooth Amp

This Amp does everything I need it to. It powers my speakers with no problems, and has inputs for my CD player via an optical connection and my turntable via RCA. I can also use the Bluetooth and connect it to my Bluetooth headphones and it has a 3.5mm headphone output for my wired headphones. All in all I am very satisfied with this amp, which looks really cool with the tubes and design.

To start, I'm using two MC331s to power four Dayton Audio MK442T Transmission line towers. The MK442Ts are a 4 Ohm load with a sensitivity of 87 db, so a bit power hungry. To feed a signal I'm using a 1Mii B06Pro+ Hi-Fi Bluetooth 5.3 Audio Receiver, connecting to the MC331s with a toslink cables.
The MC331 meets my 80 watt RMS ceiling on the MK442Ts quite nice with a 24 volt 8 amp transformer.
Now for the sound reproduction. Second to none. Tone quality is through the roof at low and higher volumes. All levels of signals can be heard but no fatiguing sounds. The MC331 is a pleasure to listen too. These amplifiers cant be beat for the quality and price.

I feel it is important to set the context: this is a review of a circa £100 amplifier.

Ordering & Delivery experience: Easy-to-use website & fast delivery - arrived on time. Simple, but well packaged.

Setup: The instructions are clear, and it is very easy to set up. As you would expect, take care when inserting the tubes - but they do also need a little bit of force. Everything is clearly labelled.

I was amazed at the build quality and not just as this price point.
I have come across much more expensive amplifiers that are nowhere near as well built.

Ultimately, we judge these things on sound quality, and this is probably the most impressive feature.

I was genuinely amazed at how this tiny little, cheap amplifier sounded.
It is a 2nd setup for me, so I have it paired with a Audio Technica LPW-40 turntable, Monitor Audio Radius 90 and a Monitor Audio Mass 2G using QED 79 strand speaker cable.

I consciously didn't try to compare it to my main setup, which is a Naim Uniti 2, Dali Opticon 6, REL Sub, and a heavily upgraded NAD 533 with a Pro-Ject PhonoBox Ulta S2.

Most of my vinyl on this setup is vinyl. Once the cutover level was set correctly and speakers/sub positioned, the listening experience is remarkable; the amplifier is very easy to use. however, I was surprised at how good the bluetooth playback was also - as I was expecting it to be "rubbish" and it really wasn't - I am now only buying a WIIM Mini for convenience of Spotify & TIDAL Connect and uPnP connectivity.

For reference, my test tracks are:
Massive Attack - Angel,
Adele - Skyfall, Hello,
Ben Howard - End of the Affair, Conrad,
London Grammar - Lord it's a Feeling, Strong,
Simple Minds - Belfast Child
Dire Straits - Money for Nothing, Telegraph Road, Brothers in Arms,
U2 - Bad, The Unforgettable Fire, With or Without You, Streets,
Hayden James - Foolproof

This system has great timing & pace, clarity (for the money and lack of bass management - I knew and wouldn't expect at this price), very good spatial layering & imaging, great atmosphere and tension.

It works well at really low volumes, but is better once about 25% volume.

Overall, I would recommend to anyone - especially at the price.

Really great product