FiiO M3K
Michael Piskor

FiiO M3K Review

The FiiO M3K is the latest generation of entry-level digital audio players and is priced at just $69.99 making it FiiO’s cheapest DAP out today.

Disclaimer: The FiiO M3K sent to us is a sample in exchange for our honest opinion. We thank FiiO for this opportunity. 

To learn more about FiiO reviews on Headfonics you can click here.

FiiO M3K
FiiO M3K
FiiO really has gone above and beyond with this one. The build quality is absurdly good and dense at 77.5g for such a small model. The touchscreen is a bit weird, but that's okay to me and doesn't intrude on the experience at all for me beyond it being a new tactile experience for me with a vertical touchpad.
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FiiO has been inside the market for portable music players for some time now. Ceaselessly expanding their prowess in the DAP field of tomorrow with new entries for our ears to enjoy.

Today, we will be looking at their ultra-budget M3K, which is a $69USD model that might be one that redefines the best budget values in the lower tier.

The Build

FiiO’s M3K is crafted from CNC aluminum and for such a small, ultraportable design, it has some nice weight to it. A lot of cheaper DAPs these days tend to offer a less dense physical appeal, which accounts for the pricing I suppose. It also comes in a silver and black option.

In this case, the $69.99 M3K has fantastic build quality. True, the screen is very budget-oriented, so do not expect an OLED or a high refresh rate. For what it is, it is just fine. Most of the time, while out and about, I am not looking at the screen anyway and just letting it play in my pocket or side bag.

For ultraportable needs, I don’t really want a great screen anyway to add to the pricing of the unit. I’d like something that offers just an okay visual experience with great sonic fidelity. Thankfully, I did receive that.

FiiO M3K

The UI

FiiO’s budget models are always basic in setup and flow. That is what I would think the general consumer would want in their experience. But, not what the typical audiophile would want. Sadly, the EQ experience is severely lacking on the M3K, as it offers no custom options and just a few presets, all of which I am very unfond of. But, that is entirely subjective.

It is one of the first instances where I vastly prefer EQ totally disabled and running on a flat experience. To my ear, everything is sonically superior with EQ entirely disabled on the M3K. I am not complaining much though, I’ll get more into this in just a bit with regard to overall response tonality and how EQ plays a part in that. For now, the user interface is comprised of just a few subset folders. Believe it or not, I really prefer this simplicity over anything complex.

Just give me an All folder, so I can shuffle all tracks, give me a basic Artists and Album folder area too. Beyond that, just one Favorites menu is all I ever really needed. Thankfully, the Favorite menu is accessed through one of the few primary folders and not hidden somewhere.

Right now, I am reviewing the $1,299USD Colorfly U8 DAP, which has a very strange placement area for their favorites men which seems to want to delete itself if I remove the sd card. However and thankfully, the M3K retains my favorites list that I’ve set up even after removing the sd card. Some DAP’s out there auto-reset that, so be careful.

FiiO M3K

A Different type of Touch

The M3K does not have a full adaptive touch display. Instead, it uses one touch sensitive vertical bar column that can be touched to raise up and down through menus and folders. Tapping the center of the column is your selection button motion.

The M3K also has four icons around the center bar that operate some basic menu functionalities. Adding favorites and toggling a few of the options in the bottom left primary function button is a bit of a nightmare sometimes, due to the touch sensitivity of the column bar being a little too sensitive and prone to skipping over what you are trying to select.

I kind of wish one of those dedicated touch buttons was purely customize-friendly. I would love to dedicate that button to ‘adding a favorite’, instead of being forced to open a menu, scroll to favoriting, select and approve. Or, even an auto EQ adjuster with a tap of a button. Anything really would have been nicer.

The Battery Life

Wow. I am beyond stunned. The M3K offers one of the best, if not the best standby times that I’ve ever seen on a portable player all year long. I am able to keep the device on and take a few days away from it entirely, just let it sit on my table, come back to it and see the battery drained just a bit.

FiiO claims a week on standby time and I think that is accurate. However, that will deplete of course if you keep the screen on and let it play, or use high-quality music files. I received well over 12 hours of normal usage with this DAP and right now that is fantastic.

I feel like we’ve taken a massive leap backward in time with regard to battery life lately. So, it is very refreshing to experience a nice, long musical experience that lasts longer than an entire workday. Good job, FiiO. This is a battery life titan. I think a lot of that has to do with the power draw from the DAC they’ve opted for.

FiiO M3K

The AK4376A DAC

FiiO has opted for a newer, modern DAC, instead of recycling some older mobile 9018 model. I am impressed with the power draw capabilities of this DAC or, at least, the lack thereof.

FiiO has explained that the AK4376A is supremely efficient on power consumption, which lends credibility to the massive standby time the unit is actually capable of. I don’t need to charge it every day. I can use it for a few hours or less, and just let it exist on my desk for a bit until a day or two passes and still have hours of time left before I require a charge. That is amazing.

Driving Power and CPU

Beyond the great DAC inside, the X1000E CPU is absurdly fast for such a budget pricing. I am able to boot up, scan an entire 200gb microSD card and start playing within 60 seconds, and by that I mean from the first initial scan in.

Boot up time is fast and scrolling through menus and tracks is a breeze. I really would like to see what this CPU can do in much more expensive models because I am really tired of expensive products lagging a lot when track skipping. I am not fond of that, but here in the M3K and with $69USD pricing in mind, I can’t really complain at all.

At 42mW on high gain, the DAP is less than moderately powerful and is clearly intended for headphones at or under 80Ω. No doubt likely intended for use with your typical sets of portables and IEM’s that are very efficient. If you need more power, odds are good you will require a portable amplifier as well. But, that is only for audiophile usage. Drop in a nice portable amp in the mid-tier, go for it. You won’t be let down by the combo, I think the M3K sounds more than clean enough to be used in a solid mid-budget portable rig.

FiiO M3K

Sound Impressions

Fidelity – Bass

Sadly, the MK3 lacks bass depth and responsiveness to bassy cues in tracks. The lacking EQ functionality makes this a lot worse on me as a bass enthusiast. I cannot achieve excellent depth and rumble here. But, thankfully, the overall fidelity and purity factor is very good. For $69USD? I have zero gripes. What is there is plenty pure and clean, bordering on reference in tonality type.

This is not a warm sounding player in the slightest. Those purists and clinical enthusiasts out there will enjoy this sound, especially anyone looking for a cheap and pure sounding unit. Usually, the very budget DAP’s out yonder have bass bloom and a sense of warmth to them that exceeds this type of tonality presentation. So, good on FiiO for choosing the more purist route here.

Bass Dynamics

The physical striking power, or dynamic kick of the low end, is sometimes too engaging for me on a subjective level. As someone who prefers musicality, my preferences are set up for a softer physical kick and slam factor on the low end and I do not enjoy wince factor. The wince factor on a flat EQ offered is one of a moderately powerful tendency.

Those who like engaging and pure sounding bass will love this. However, those who want a softer, more wooly type of bass with a slower decay will not enjoy it. That is entirely subjective and only a statement for consumers looking for a specific sound. Those consumers who just want a good sounding player do not need to worry, it all sounds good overall.


This FiiO M3K is moderately presented in the vocal experience. I have a few other DAP’s released in 2018 that offer a more forward, or more relaxed presentation. So, the middle ground is where the midrange experience is and I feel that to be the wisest course of action.

The sound of the player, with regard to vocals, is in what I consider the “safe zone”. Meaning, it caters to most listeners preferences. Forward tracks sound plenty forward, very relaxing and wide tracks sound plenty relaxed. It doesn’t at all lack anywhere specifically, but there are better options if you are looking for a specific vocal experience.

Midrange fidelity for this price is stellar. I am extremely impressed, once again, with the overall purity factor being offered The only gripe I have is that sometimes the upper midrange areas can sound a bit too sharp and pure. Sometimes, sudden piano key strikes and vocal cues are a bit startling, but not overly so.

Again, purity usually equates to some wince factor and that is okay so long as it doesn’t go overboard. It doesn’t go overboard in the M3K, but I would have preferred a bit more heft and density factor to the vocal experiences than what is there.

FiiO M3K


The M3K wins the award for some of the most beautiful and tamed treble I’ve heard in an ultraportable. It positively shredded the Xduoo X3ii that I’ve recently reviewed, making it sound overly hazy and muted.

The entire top end of this player is a stark contrast to the rest of what is offered, where everything else seems purist based, the top end here gently bright and musical. I really love this type of tonality and it fit immensely well with my older AKG K267, which has amazing treble capabilities, even my Flare Audio R2Pro’s sounded amazing! I am so happy with the tonality of the top end.

You just don’t hear this type of a musical tendency these days and I wish FiiO would make a very warm, very musical sounding DAP in this ultraportable tier sometime soon to complement the sound of the M3K. The treble presence and dynamic kick are less than moderate and closer to the bottom end of the tier. Meaning, it is further from slamming than it is from very soft.


Soundstage depth of field is excellent and competes with much more experience DAP’s that I own. That forward stage presence and realism in reaching out into the front side of the void potential is quite amazing for only $69.

Height and overall width are just okay, as are vocal realism and instrument density factor in the void itself. By that, I mean that the imaging properties are just shoulder shrug-worthy beyond the excellent depth of field factor. My ears crave much more width to compensate for the amazing depth factor that is offered.

Vocal and instrumental separation properties are good, but not great. Again, if you want that, Xduoo’s X3ii might be better for you as a staging enthusiast. For now, the imaging properties of the MK3 are overall just good and more than passable. If you have some budget headphones with excellent depth of field factor, like a Denon D2000 or similar IEM, then this is a great option for you.

FiiO M3K

Select Comparisons

Hidizs AP80 and Shanling M0 vs FiiO M3K

The Shanling M0 is currently priced at $109 MSRP and the Hidizs AP80 is priced at $115. Both of them are a fair deal more expensive, but not too much. All of them are in the budget tier parameters. The gap between the M0 and the M3K is smaller than the gap between the AP80 and the M3K, all of these devices sound and feel different and there is a lot to discuss about how each differs from the other.

FiiO M3K

Shanling M0


FiiO’s overall tonality is less dense feeling and lacking a sense of vividness. Although right off the back, A vs B comparisons showcase the M3K’s superior staging in depth of field factor, while both sound generally the same in overall width and height factors.

Coherent instrument and vocalist formations, meaning, the realism factor, is a little superior on the M0, but not by much. At this price range, I feel like I’d subjectively prefer the superior depth factor of the M3K, it gives my ears something to hold onto with regard to the stereo void.

Interesting “somethings” are better to me than how pure something sounds, as my ears, again subjectively, get bored after a while on the M0 with regard to imaging. However, the M0’s bottom end potential is noticeably more rumble and deep-reaching.

Tonality on the top end of the M0 feels a bit drier, less interesting. FiiO did a marvelous job with the treble response and I had already enjoyed the M0’s treble, to begin with, yet feel the M3K to be a little more clean feeling at times.

Although, again, density factor and heft are noticeably superior on the M0. The UI functionality of the M3K is also easier to navigate, but for me, that is due to the touchscreen size of the M0 being very small.

Shanling M0

Hidizs AP80


The AP80 is quite a step up in fidelity across the board, especially so when I forgot that I had custom EQ settings activated on the AP80 right when I started my comparison processes. With that in mind, the AP80 offers significantly more staging coherency and bass response.

The entire tonality and presentation feels much denser and weighted from top to bottom. As nice as the treble response is on the M3K and the M0, the AP80’s stock sound on top of the spectrum feels noticeably cleaner than the M3K and the M0. It can be highly customized with the MSEB functions inside, that EQ system is absolutely stellar.

It is also nice to have full touchscreen capabilities on both the M0 and the AP80, whereas the M3K has a touch bar and only four touch-sensitive areas on the screen in regards to four small buttons on each corner of the panel.

Shockingly, the M3K nearly doubles the battery life of both the M0 and the AP80 and 10x’ed the standby time of both of them as well. In terms of battery prowess, the M3K reigns supreme. The UI experience on the AP80 is vastly superior, more detailed, and complex. Where the M3K is very basic and bare by comparison, the AP80 is dynamic and feature-rich.

Hidizs AP80

Our Verdict

FiiO really has gone above and beyond with this one. The build quality is absurdly good and dense at 77.5g for such a small model. The touchscreen is a bit weird, but that’s okay to me and doesn’t intrude on the experience at all for me beyond it being a new tactile experience for me with a vertical touchpad.

Beyond that, the unit is very pure sounding until you get to the top end, where things got very musical and hyper enjoyable for me.

Sometimes, I listen to classical music and screaming guitars and find myself air-playing to myself in front of others…because I find the treble response and presentation that enjoyable. Right now, my sample is a beta unit and did not include custom EQ. However, FiiO has told me that they will be updating the M3K with custom EQ very soon!

The M3K is only $69.99USD and offers some of the best battery life and treble I’ve seen in a long time for such a budget-oriented model. Great job, FiiO. This is a keeper.

FiiO M3K Specifications

Main Unit

CPU model Ingenic X1000/E,40nm
CPU operating frequency 1GHz
Keyboard Touch button
Special features Long battery life, Deep sleep, Recording, Repeat
Chips used SoC: Ingenic X1000/E,DAC:AK4376A
Operating System Linux
No. of cores Single
Input method Touch button+Physical button
User interface Deeply customized


WiFi N/A
USB Micro USB2.0
Bluetooth N/A

Display screen

Display size 2.0 inches
Display type IPS TFT
Resolution 240×320
Touchscreen N/A
Number of colors 262K
Viewable angle Full-view
Pixel density(PPI) 200


Storage expansion type Micro SD
Maximum storage expansion Theoretically 2TB (only one micro SD card slot)
ROM available to the user N/A

Buttons and ports

Buttons Touch button+Physical button
Headphone out (PO) Standard 3.5mm stereo jack decorated with metal ring
USB Micro USB2.0
(Charging/Data transfer/OTG/USB DAC)


Color Silver(might have more colors coming out)
Weight About 77.5g
Recommended headphone impedance 16~100Ω
Treble control N/A
Balance control ±5dB
USB DAC Asynchronous USB Dac, up to 192kHz/24bit supported
Dimensions 90.8mm×44.2mm×12mm
Volume control 60 steps digital potentiometer
Equalizer 5-band EQ (±6dB),7 presets
Bass boost N/A
Gain control N/A
Highest sample rate supported 384kHz/32bit

Power specifications

USB power adapter DC 5V/2A Recommended
Charging indication Large charging icon shows on display when it’s off,
small charging icon shows on the upper right of
 display when it’s on
Battery capacity 1100mAh Li-polymer battery
<2.5 h (DC5V/2A)
Battery indication – Yes
Battery Life & Test Conditions
3.5mm headphone output:>24h
Volume 24
Screen OFF
Load M3 open earbuds (27 Ω)
Test File MP3 44.1kHz/16bit
Recording Supported
Date&Clock Supported
A-B Repeat Supported
USB OTG Supported

Headphone out specifications

Output power 1 ≥42mW(16Ω / THD+N<1%)
Output power 2 ≥25mW(32Ω /THD+N<1%)
Frequency response 5Hz~90 kHz(-3dB)
SNR ≥117dB (A-weighted)
Output impedance <1Ω(32Ω)
THD+N <0.004%(1kHz/32Ω)
Noise floor <2uV
Peak output voltage 2.46Vp-p

File format support

Lossless: DSD:DSD64(“.iso”“.dsf”,“.dff”)
APE(Fast): 192 kHz/24 bit
APE(Normal): 96 kHz/24 bit
APE (High): 96 kHz/24 bit
FLAC: 192 kHz/24 bit
WAV: 384 kHz/32 bit
Aiff:192 kHz/24 bit
Aif:192 kHz/24 bit
WMA Lossless: 48 kHz/24 bit
Apple Lossless: 192 kHz/24 bit

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