I spent some time using the new Fosi device, MD3 and just wanted to share here my impressions 
First Impressions
Solid built, it has a metal body that feels good and kinda premium.
That magnetic system? At first I thought it was just a gimmick. After a few days, I realized it solves something annoying that every dongle DAC has, they’re always hanging awkwardly somewhere.
With the MD3, you just place it where it makes sense. Desk, handheld, even attached behind a device, in my case, I have one of those carts from general US, this is where I`m placing mine, the magnet is just glued to the metal, it becomes part of your setup instead of something dangling off it. Mine, I'm keeping in my metal general US cart really close to my desk.
Setup I Used
Sources
Comparisons
Headphones / IEMs
What the MD3 Is Actually For (in my opinion)
The MD3 is not:
The MD3 is for:
Sound Performance
The MD3 leans toward:
It doesn’t try to sound “impressive” or exaggerated but it still sounding pretty good
With HD600
This is where expectations need to be realistic.
It’s usable, but not ideal if that’s your main headphone.
With IEMs (Where It Shines)
This is clearly its strongest use case.
With something like the Alba, it feels effortless. No need to think about power, gain, or anything, just plug and play.
Versus Apple Dongle
Clear upgrade:
Not night and day, but enough that you notice quickly.
Versus DS3
This is the real comparison.
You choose the MD3 if:
Screen & How to Use It (Quick Practical Guide)
How to Use It
Volume up and down → adjust volume
Press 3rd button on the side → switch modes / confirm selections
On the front button: press is going to change image, double press is going to change folder
Pros
Cons
The MD3 is not trying to win on specs or power. That’s not the point.
It’s one of those products where the value comes from how it fits into your life, not just how it measures.
After using it, I’d put it like this:
Let me know in the comments what you guys think and if you guys have any question
First Impressions
Solid built, it has a metal body that feels good and kinda premium.
That magnetic system? At first I thought it was just a gimmick. After a few days, I realized it solves something annoying that every dongle DAC has, they’re always hanging awkwardly somewhere.
With the MD3, you just place it where it makes sense. Desk, handheld, even attached behind a device, in my case, I have one of those carts from general US, this is where I`m placing mine, the magnet is just glued to the metal, it becomes part of your setup instead of something dangling off it. Mine, I'm keeping in my metal general US cart really close to my desk.
Setup I Used
Sources
- ROG Ally X
- iPhone 16 Pro (main use case)
Comparisons
- Apple dongle
- Fosi DS3
- Fosi K7 (reference point)
Headphones / IEMs
- HD600
- Meze Alba
- Master and dynamics mw50+
What the MD3 Is Actually For (in my opinion)
The MD3 is not:
- A power-focused DAC
- A desktop replacement
- A “feature-packed” device
The MD3 is for:
- daily listening
- Portable setups that don’t feel messy
- IEM users who want better quality without bulk
- People tired of dongles hanging off their phone or handheld
Sound Performance
The MD3 leans toward:
- Clean
- Slightly smooth
- Non-fatiguing
It doesn’t try to sound “impressive” or exaggerated but it still sounding pretty good
With HD600
This is where expectations need to be realistic.
- It can drive them
- But it’s not pushing them to their full potential
- Lacks a bit of energy and headroom compared to DS3 and mainly the K7
It’s usable, but not ideal if that’s your main headphone.
With IEMs (Where It Shines)
This is clearly its strongest use case.
- Very clean background (no hiss)
- Great separation
- Balanced output makes a difference
With something like the Alba, it feels effortless. No need to think about power, gain, or anything, just plug and play.
Versus Apple Dongle
Clear upgrade:
- Better detail retrieval
- More controlled bass
- Wider sense of space
Not night and day, but enough that you notice quickly.
Versus DS3
This is the real comparison.
- DS3 = more power, more impact, more “wow”
- MD3 = smoother, lighter, easier to live with
You choose the MD3 if:
- You hate messy cables and dangling DACs
- You use IEMs or easy-to-drive headphones
- You want something small that still feels premium
- You move between devices constantly
- You don’t want to deal with apps, EQs, or settings
- You like retro visual (It is pretty solid looking)
Screen & How to Use It (Quick Practical Guide)
How to Use It
Volume up and down → adjust volume
Press 3rd button on the side → switch modes / confirm selections
On the front button: press is going to change image, double press is going to change folder
Pros
- Magnetic design actually improves usability
- Very portable and clean setup
- Excellent for IEMs
- Balanced output included
- No learning curve, just works
Cons
- Not ideal for demanding headphones
- Magnetic feature isn’t useful for everyone
- Short cable
- USBC port in the bottom is too close to the 3.5mm jack
- Slightly overpriced if you only care about sound
The MD3 is not trying to win on specs or power. That’s not the point.
It’s one of those products where the value comes from how it fits into your life, not just how it measures.
After using it, I’d put it like this:
- If you sit at a desk and want performance MD3 is not the product you need right now
- If you’re moving around and want something clean and effortless → MD3 makes more sense
Let me know in the comments what you guys think and if you guys have any question
