Fosi Audio MC331 Tube Integrated Amplifier with DAC

Classic Tube Warmth. Modern Audio Versatility.

The Fosi Audio MC331 combines a tube amplifier, DAC, preamplifier and headphone amplifier in one compact desktop unit. With its distinctive 5654W vacuum tubes and mini VU meter, the MC331 blends a classic retro aesthetic with modern connectivity and powerful stereo amplification.

All-in-One Audio System

Simplify your setup with multiple audio functions in one unit.

The MC331 works as a DAC, integrated amplifier, preamp and headphone amplifier, allowing you to connect different sources and enjoy your music through passive speakers or headphones.

Warm Tube Sound & Retro Style

Experience the character of vacuum tube amplification with the included 5654W tubes.

The tubes can also be replaced with compatible models such as 6AK5, 6AK5W, 6Zh1P and 6J1, giving enthusiasts the flexibility to experiment with different tube characteristics.

The built-in VU meter adds a classic visual touch while responding to your music.

Powerful Stereo Amplification

Despite its compact size, the MC331 delivers up to 105W × 2 @ 4Ω, making it suitable for driving bookshelf and other compatible passive speakers.

With support for 4–8Ω speakers, it provides a flexible solution for compact home and desktop Hi-Fi systems.

Versatile Connectivity

Connect a wide range of audio sources through Bluetooth, USB, optical, coaxial and RCA inputs.

The MC331 also features passive speaker outputs, pre-out and a 3.5mm headphone output, allowing you to build a flexible system around your preferred speakers and headphones.

Easy Sound Control

Fine-tune your listening experience with dedicated bass and treble controls.

The included remote control lets you switch audio sources and adjust settings conveniently from your listening position.

Compact Desktop Design

The MC331 is designed to deliver powerful performance without taking up unnecessary space.

Its compact 10 × 2 × 2.7-inch chassis makes it suitable for desktop setups, bedrooms, offices and smaller listening spaces.

Why Choose the Fosi Audio MC331?

• All-in-one DAC, integrated amp, preamp and headphone amp
• 5654W vacuum tube design
• Replaceable vacuum tubes
• Mini VU meter with retro styling
• Up to 105W × 2 @ 4Ω
• Supports 4–8Ω speakers
• Bluetooth, USB, optical, coaxial and RCA inputs
• Passive speaker output
• Pre-out
• 3.5mm headphone output
• Bass and treble controls
• Remote control included
• SNR ≥100dB
• THD ≤0.03%
• Compact desktop design
• Ideal for bookshelf speakers, headphones and desktop Hi-Fi systems

What's in the Box?

• Fosi Audio MC331 Amplifier
• 24V/4.5A Power Adapter
• Remote Control
• User Manual