Fosi Audio MD3

Fosi Audio MD3 MagDac

Portable Magnetic DAC / Headphone Amp

Moments Away, Fully Enjoyed

Why We Built MD3?

Traditional dongle DAC/amps often feel awkward to use—hanging from the phone, pulling on cables, and falling short on true portability. Some units add a screen, but it’s usually limited to basic information like volume, with little presence or purpose.

We wanted to break away from this pattern.

MD3 features a strong magnetic backplate that securely attaches to your phone, while its lightweight, compact design makes it effortless to carry wherever you go. We also adopted a circular display not just to show essential audio information, but to make interaction feel alive. Paired with the Vista Button, it lets you browse a photo album and upload images you love. MD3 represents our pursuit of balance in sound, design, and interaction. We hope MD3 becomes a companion you’ll want to take with you wherever you go.

THE SOUND

What Does MD3 Sound Like?

Built as a HiFi–grade DAC/amp with no compromises in sound, MD3 offers a detailed yet musical listening experience.

Rich in Detail

Faithfully tuned to honor artistic intent and reveal the finest nuances, MD3 supports PCM 32bit/384kHz and native DSD256, with THD+N down to 0.00075% for detailed, lossless listening.

Clean Background

MD3 keeps music free from unwanted noise. Thanks to its aluminum alloy construction and well-engineered circuitry, the noise floor is reduced to 1.7μV, with a signal-to-noise ratio of up to 116dB.

Musical Tuning

Based on ensuring accurate reproduction, the MD3's sound tuning is more natural and enduring. It adds a slightly warm tone, making it more suitable for all-day listening.

SOUND FIRST. ALWAYS.

Why We Chose the ESS Chipset?

In pursuit of ultimate resolution and listening excellence, our acoustic team conducted extensive comparisons and listening tests across mainstream chip solutions, including RT6863 and SGM8262. Rather than following the conventional path of maximizing raw power at the expense of sound quality, we chose the higher-cost yet sonically superior ESS flagship solution.

The ES9039Q2M flagship DAC chip delivers exceptional resolution, while its low power consumption makes MD3 an ideal audio companion for mobile devices.

A balanced amplifier circuit with four ES9603Q op-amps drives headphones with excellent separation, delivering a richly musical, fatigue-free sound.

PLAYABILITY

Photo Album

MD3 comes with built-in funny animated images and emojis. You can also turn the outer display into your canvas with DIY wallpapers, from family photos to images of your favorite artists.

A LITTLE FUN.

Fun Image Games

Built-in games like dice rolling, spin the bottle add a playful touch. Take a lighthearted break anytime, anywhere—right alongside your music.

Rich in Detail

Clean Background

Musical Tuning

JUST SNAP IT ON

Your Phone’s Little Backpack

Sixteen N52 high-strength magnets keep MD3 firmly attached to your iphone. Say goodbye to straps, bulk, and clunky distractions. An aluminum alloy isolation plate separates the PCB from the magnets, so you don’t have to worry about magnetic interference affecting sound quality.

Vista Button

Press to enter the photo album and you can flip through images with ease. After a long day of work, a simple press and its crisp, tactile response offer a small moment of stress relief.

Add A Playful Touch

The grid area beneath the display is designed as a canvas for your creativity—decorate it with stickers you love.

OFFICE. COMMUTE. PLAY.

On-the-Go Listening

Thanks to its compact size and magnetic design, you can take MD3 everywhere. Why not let high-fidelity sound stay by your side?

DESIGN

Maybe this is what the future of DAC/Amp feels like.

Precision-anodized aluminum meets hand-stitched leather. Metal and warmth, in harmony.

Magnetic Backplate

Premium leather back, gentle on your phone and comfortable in hand.

1.28-inch LCD Display

Fully laminated circular display with screen rotation, brightness adjustment, and auto screen-off.

Vinyl-Inspired Texture

Where vintage spirit meets modern craftsmanship — the way HiFi should be.

COLOR MATERIAL FINISH

Two Bold Finishes

Anodized silver, anodized black. Both with orange leather.

FEATURES

Thoughtful Design

With precision in every detail, MD3 makes listening simple and elegant.

Ultra-Portable

Lightweight at only 50 g, it is designed to go anywhere without holding you back.

0.47 inch Optimized Thickness

Balanced slimness and usability: This thickness prevents bulky headphone plugs from lifting the MD3 slightly off the phone, ensuring magnetic attachment .

100-Step Volume Control

One step too loud, one step too quiet? MD3 delivers finer volume control to find your perfect comfort zone.

Volume Memory

Set the volume once. MD3 automatically remembers it for you.

USB-C

Audio Decoding/Image Transfer/Charging

Note: Connect this port to external power; the bottom USB-C port can charges your phone.

Portable Magnetic DAC / Headphone Amp

Moments Away, Fully Enjoyed

Why We Built MD3?

Flagship DAC Chip

1.28" Round LCD Display

Photo Album

Aluminum Alloy Chassis

Premium Amplifier Chips

100-Step Volume Control

N52 Magnetic Backplate

Ultra-Portable

THE SOUND

What Does MD3 Sound Like?

Rich in Detail

Clean Background

Musical Tuning

SOUND FIRST. ALWAYS.

Why We Chose the ESS Chipset?

PLAYABILITY

Photo Album

A LITTLE FUN.

Fun Image Games

Rich in Detail

Clean Background

Musical Tuning

JUST SNAP IT ON

Your Phone’s Little Backpack

Vista Button

Add A Playful Touch

OFFICE. COMMUTE. PLAY.

On-the-Go Listening

DESIGN

Maybe this is what the future of DAC/Amp feels like.

Magnetic Backplate

1.28-inch LCD Display

Vinyl-Inspired Texture

COLOR MATERIAL FINISH

Two Bold Finishes

FEATURES

Thoughtful Design

Ultra-Portable

0.47 inch Optimized Thickness

100-Step Volume Control

Volume Memory

USB-C

Audio Decoding/Image Transfer/Charging

N52 Magnetic
Backplate