Fosi Audio MD3

The MD3 MagDac from Fosi Audio is a compact, portable DAC and headphone amplifier designed specifically for mobile use with smartphones. The device combines high-quality audio processing with a magnetic attachment system and an interactive design, making it the perfect audio companion to take with you wherever you go.

The MD3 features a magnetic back panel with sixteen powerful N52 magnets, allowing the device to attach securely to a smartphone. This design eliminates the typical “dongle feel” where a DAC hangs loosely from the phone, providing a more stable and practical mobile experience.

At the heart of the MD3 is an ESS ES9039Q2M DAC chip, combined with four ES9603Q operational amplifiers. This configuration supports PCM audio up to 32-bit/384 kHz and native DSD256 and is designed to deliver high-resolution, low-distortion, and detailed sound reproduction. The amplification section ensures good channel separation and a smooth, musical sound balance.

The sound reproduction is tuned for a slight warmth and long-term listening comfort, aiming for a natural and non-fatiguing character. The signal-to-noise ratio reaches 116 dB and distortion remains extremely low, contributing to a clean and transparent audio reproduction.

The MD3 features a 1.28-inch round LCD display that not only shows basic information but also enables interaction via a so-called Vista Button. This allows users to browse photos, customize wallpapers, and even personalize small visual elements. In addition, playful features such as digital dice and other mini-games are integrated.

The device supports both a 3.5 mm single-ended output and a 4.4 mm balanced output, with power output of up to 180 mW per channel at 32 ohms on the balanced output. This makes the MD3 suitable for a wide range of headphones with impedances between 16 and 300 ohms.

The housing is made of aluminum and combines a lightweight construction of only about 50 grams with a slim design measuring 70 × 45 × 12 mm. Two USB-C ports provide separate functions for audio, firmware updates, and simultaneous charging of both the phone and the DAC.

The MD3 is designed as a mobile hi-fi solution that combines portability, high-quality sound reproduction, and interactive features in a single compact device for everyday use on the go.