A Tube Amp Under $200? Fosi MC331 Amplifier Review

Tube amplifiers are famously known for being rather intense upgrades to audiophile systems. They can cost thousands of dollars, so it's definitely a purchase to make after some careful consideration. Fosi Audio has come in with a new tube amplifier that retails for under $200. The Fosi MC331 is a Bluetooth integrated tube amplifier and DAC that serves as a one-stop shop for your gear upgrade needs. How can an amplifier that does so much be retailing at so little? Our review of the MC331 tells all. 

The first thing I notice about this amplifier isn't the features or the connectivity, but the aesthetics. The MC331 is visually stunning: there is no doubt about it. It is a smaller unit that has an all black body, paired with orange accents on the tube coverings and on the knobs in the front. The tubes give it a retro look, especially when paired with the orange glow of the analog VU meter. It doesn't take up a lot of real estate on a desk, though you will need to account for setting up next to an outlet to connect to DC power. 

Setting up this amplifier is relatively simple, but it should be noted that the MC331 is a delicate piece. With the vacuum tubes on top, wearing gloves is best to ensure the pieces are kept clean and in good condition for longer. Fosi Audio recommends letting the amplifier warm up for 15-20 seconds before using.

• MAX Power Output: 105W×2@4Ω
• Input Mode: Bluetooth +RCA +USB +COA+OPT
• Output Mode: Passive Speakers Output, Pre-Out, 3.5mm Headphone Output
• THD: ≤0.03%
• SNR: ≥100dB
• Device Dimension: 10 x 2 x 2.7 inches
• Terminating Impedance: 4-8 Ω
• Power Supply: 24V/4.5A

The Fosi Audio MC331 is a powerful and clean amplifier. For my listening, I was impressed with the quality that came out using both wired and wireless inputs. To test out the amplifier and how it sounded, I used a few different headphones to test compatibility:

• Fosi Audio i5
• Sennheiser HD 600
• Hifiman Ananda Unveiled
• Meze 105 SILVA

The MC331 drove the Sennheiser HD 600 with ease, and the Fosi i5 had some great synergy for my taste. I like pairing this amp with a more treble-leaning headphone, or something that is meant to be more analytical. The MC331 was good for integrating a harder-to-drive headphone and giving it a bit more warmth. Even on Bluetooth, there was impressive power coming from the amplifier, and there was great clarity too. No drop-offs, cutting out, or power that was held back because of a wireless connection. 

The knobs on the MC331 allowed you to adjust the bass and treble to your liking, all while keeping the tonality and timbre coming from the headphones fairly honest. The bass boost was just enough to give any headphones a bit more sub-bass rumble. The treble sharpened up the top end to give you just a bit more clarity and balance out some bassier headphones. 

After extensive listening, I could see how the MC331 may have more speaker application in mind as opposed to headphones. While it did drive a lot of headphones with ease, I was more interested in how the MC331 would perform when powering a room's sound as opposed to just in a pair of headphones. 

The Fosi Audio MC331 showcases some impressive features in a small package. The vacuum tubes and VU meter give you a retro aesthetic to add to your listening setup. You're going to get smooth sound that pairs well with analytical headphones, and the adjustable knobs allow you to tune the headphones to your exact liking. On top of the good sound and clever looks, the adaptability and versatility of the various inputs and outputs make this an incredible value. 

If you're looking for a headphone amplifier, the MC331 is a safe buy. It's got everything you need and more to be used however you listen to music, and for an incredibly affordable $129.99. That being said, my personal preference would say it's better as a speaker amplifier than it is for headphones. I think the MC331 is a safe buy for any setup, but it would thrive and shine the most when paired with a nice pair of passive speakers. 

The Fosi MC331 is available at Audio46.