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

I initially intended to conduct a thorough review of this integrated amplifier, but honestly, for just $130 and the exceptional sound quality it delivers, why write a lengthy review? I've A/B tested the Fosi MC331 on both a $3K audio system and a $15K system, and I can confidently say that for the price, the performance is great. If you're in the market for a budget-friendly option that doesn't compromise on audio performance, Just Buy It! 😎

My MC331 is better than I had anticipated (with a couple caveats). The sound is clear, and the tubes impart with slight warmth you look for with a tube (hybrid) amplifier. 100W is plenty enough for my desktop needs, and I wouldn't hesitate using it with larger (efficient) speakers. The Bass/Treble adjustments are adequate but coarse. I paired this with application based EQ for great results. I love the retro VU meter and the front panel headphone jack (3.5mm). It supports a variety of inputs and the dial to select them is easy to use. I noticed a low level noise in RCA mode that persisted after 3 different sets of tubes, but an in-line attenuator solved the problem.I recommend the Fosi MC331 for folks who want a bit better (nostalgic) sound from a small footprint amplifier. Bluetooth makes it convenient to use with phones, tablets, etc as well. One note however, it is considerably smaller than the product photography makes it appear.

Purchased during a Lightning Sale with 20% off. Unit is very versatile and use primarily to drive earphones with keyboard. All controls and performance are as expected. However three annoying "features". All center on controls, settings, and persistence.1. When turned on, the input resorts to the default of BT. I have to re-set to RCA input.2. When turned on, the volume resets to 0, requiring re-adjustment.3. Really not persistence, but the bass and treble controls are reversed from customy position. Left is treble, Right is Bass. Lucily don't have to adjust this anymore with my primary keyboard source.So, if you don't mind the quirks, it works well. I'm keeping mine, since it's sound performance is the critical factor. Caveat Emptor.

Using with my Mac Studio. Blows the doors off the Mac’s DAC. Fantastic sound. Utterly amazed something that small can sound that good. Bought this after getting Fosi mono blocks to drive my Inifinity RS 2.5s. Those also sound great.

Lower power than the Douk Audio amp which is even cheaper. But it's sound good.

A few years back I bought a Bottlehead tube amplifier kit & built it. I spent hours inside my Sennheiser HD650 headphones powered by that amp & loved them both dearly. Then, like most people, I began to think if that combo was good there must be better. I sold the amp & have missed it ever since. So I bought this inexpensive tube hybrid on a whim. Knowing it takes time to burn in tube amps & also my new Fiio FT-1 Pro planars, I spent the evenings of the last week just listening. At the end of the week both were smoother & warmer. And I must confess that I am VERY impressed with this tiny amplifier! It will never drive a pair of speakers because it is strictly a headphone amp with My Astell&Kern feeding it through bluetooth into my FT-1 Pro headphones. The amp & headphones are $300 together, so this is probably the sweetest place I can think to listen to my favorite music for an absolute steal of a price!

This amp sounds great when playing at moderate volumes. Worked good with my TV and streaming music.I then took it to work to use as a desktop DAC/Amp with the same speakers (Micca MB42x G2s). It failed pretty miserably in that application. With the volume low when the audio track dips to vocals only or light instrumentals it will cut out entirely. In order to mitigate this I had to turn it up to a volume level that is not appropriate for an office setting.With a different Dayton amp the speakers functioned perfectly. I found a small thread on a forum discussing this and several others are having the same experience. Supposedly Fosi is working on a solution but I believe I will be returning this unit.

I bought this to replace my S.M.S.L because it just didn't have the power or sound quality I was looking for. I have this new little beast running my B&O S60 speakers and it's night and day different. The sound is as advertised with a warm and powerful sound that I wasn't expecting from a little amplifier. Having the remote and being able to use this with my WIIM streaming box was a huge plus. I very much recommend this product however if you are new to tube amplifiers. I would recommend watching a video or two to learn more on how they work and how to change out the tubes. Touching the tubes with your bare fingers or anything with oils is not recommended and reduces the life. Just a quick tip for the newbies:)