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

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 had heard good things about this manufacturer's amplifiers, and I needed something a little more than a one input amplifier. This integrated amplifier allows you to connect via Bluetooth, USB-C, RCA and optical, allowing me to use this to connect to an Arylic streamer and my PC. I was initially reluctant to purchase something that uses tube technology, since I'm not sure how long they will last. My previous solid state receiver lasted 20 years with no issues until last month when it started getting cross talk issues between FM and other inputs. With the Fosi MC 331 on sale I thought I'd take a chance. My concerns are unfounded so far, since the tubes are only for the pre-amp stage and are easy to insert and replace. I've even come across some suggested tubes that allegedly improve the sound, although the sound with the included tubes is terrific. I'm not crazy about the user interface, since the volume dial is used to adjust the volume, switch between the sources by single clicking, and a power switch, by long pressing. I have some unusual banana plugs that I was unable to use since they are not the usual type but are flexible and intended to be used in the clip type speaker posts but this amp only allows for standard rigid banana plugs and using bare wire to insert into holes under the twist-tight speaker posts. You'll be better off with thinner speaker wire if you don't have rigid banana plugs and need to attach using bare wire, as the 14 AWG speaker wire I use barely fits. Thinner wires are fine for shorter runs, so I wouldn't be worried if this were to power nearby bookshelf speakers, which I suspect will be the most frequent use case for this amp. The built-in Texas Instrument DAC allows this to be connected to my PC via USB-C cable and the improvement over the original Realtek sound from the HP PC and RCA cables was noticeable. Some caveats: the manufacturer provides tube protectors to keep you from touching the glass tubes as they are fragile and get quite hot so don't touch them with the power on. It takes the tubes 15 to 20 seconds to warm up, so make sure to turn the amp on before you sit down to enjoy your music. This amp is tiny and fits easily on the shelf with the shelf speakers, which are 10 1/2 inches tall. By comparison. the receiver this replaced took up all the available shelf space. Have to move some stuff around now with the extra space. This also has a headphone amp, but note that while using the headphone output, the speaker outputs are not available. A remote control is included, but you'll need two AAA batteries, as none are supplied. If I run into any issues with this I'll update the review, but so far very happy with this purchase.

どのモ−ドでも音質が良いいですがモ−ドの表示が小さく見づらいことがある。

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.

Un pre amplificador con un dac integrado que le da calidez a las cuerdas y voces, ayuda muchísimo cuando quieres modular graves o agudos y en general tiene un gran desempeño.

Very nice sounding amplifier, amazing with my Bose series 4

Excelente