FiiO M23

The FiiO M23 is a new DAP that is meant to be a successor to the popular M11 Pro ESS. It uses a new, flagship AKM chip and it's priced at $699.

Introduction to the FiiO M23 Review

FiiO is one of those companies, that certainly don’t need any introduction. For years now, they always impressed me with their exceptional DAPs that offer an impressive value. 

Last year we’ve reviewed FiiO M11 Plus ESS.

Now, we’re taking a look at their newest release in this review, FiiO M23. It’s meant to be a successor to the M11 Plus ESS, while also costing a $100 less than its predecessor. Let’s dive right in, and see, what’s changed and how does it perform.


First up, we’ll take a look at the packaging and the overall unboxing experience. This time, the reviewed FiiO M23 comes in a clean, white box that looks good and is of good quality.

Inside the packaging, you’ll find some necessary essentials, such as a USB C-A cable with a USB-A converter, a pin for opening the SD card slot, and a transparent case.

It’s always good to see manufacturers including a case in the box. While the case you’ll be getting for the FiiO M23 is nothing to write a book about, it’s an added layer of protection for free, which is a good thing. 

There is no leather case in the box, or any added gadgets and accessories. However, considering the competitive market and the aggressive pricing of the reviewed FiiO M23, this should come as no surprise. 

Overall, the unboxing experience here is good and I have no complaints. Let’s move forward.

Design and Build Quality

Reviewed FiiO M23

The new FiiO M23 is following the aesthetics of its older brother, the M11 Plus ESS. I use my standard argument here – why change a thing that simply works?

Having that in mind, tested FiiO M23 is a very well-built and good-looking device. It feels sturdy, comfortable to hold and it looks very pretty. I really love the color of the device, which is a dark navy-blue tint that looks gorgeous, especially in daylight. The back of the device has a glass panel with some really unique and striking-looking reflections. It’s hard to get it on camera, but trust me…it looks absolutely spectacular.

On the right side, there are classic buttons for play/pause, next and previous song, a hold toggle, and a desktop mode toggle. The hold toggle is a good thing to have, to avoid accidental changes of volume. 

Speaking of changing the volume, it’s done by a touch panel that’s located on the left side of the device. It has a carbon-fibre texture that not only looks good, but also provides a proper grip and control. Design meets function, that’s what I like. You can adjust the volume by clicking up and down or sliding it with your finger, and I’ve never had any issues with it. It works well.

The front of the reviewed FiiO M23 is occupied by a 5.5inch, IPS screen with a resolution of 1440×720. The screen gets plenty bright, it’s sharp, and has good colors and decent black levels. It’s not an OLED, so don’t expect true blacks, but do you really need them in a DAP?

Reviewed FiiO M23 connectors

The thing that I like a lot is that FiiO decided to split USB inputs from headphone outputs. The outputs are located on the top of the device. You have access to a 3.5mm output that has 3 modes – headphones out, line out, and coax. The other output is a 4.4mm one which also can work as a line-out. Of course, if you have a balanced cable, I hugely recommend using the 4.4mm output at all times.

On the bottom of reviewed FiiO M23, you’ll find an SD-card slot, a USB-C socket, and another USB socket marked as “power in”. This is meant for the new Desktop Mode, but more on that later. 

To summarize, tested FiiO M23 is a beautiful DAP with a flawless build quality. It’s a pleasure to use it and hold it in your hand, and many of you will be surprised of its quality, considering the asking price. Well done, FiiO!


Now, let’s get into technical stuff, shall we?

First of all, reviewed FiiO M23 is built around the flagship AKM chip, which is AK4191EQ+AK4499EX. Quoting FiiO: “It is a new design that totally separates the digital and analog portions and also features the “DWA ROUTING technology” “.
“These technologies allow for a purer audio background and for higher resolution audio -resulting in a relaxed yet natural sound”.

Apart from the marketing here, we’re talking about a flagship AKM chip, which is something to praise in this budget, especially considering all the other things you’re getting. It always surprised me how much tech modern DAPs pack, and yet they don’t cost thousands of dollars. What’s also interesting about this chip, is that it has separated digital and analog processing, which further improves the general performance of the chip.

When it comes to amplification, reviewed FiiO M23 packs an impressive technology as well. It uses a 4-way fully balanced THX AAA 78+ design. This amplifier is an upgraded version of the THX AAA 78 that was present in the M11 Pro and M11 Plus. It now allows for higher power output, basically doubling the numbers found in the M11 Plus ESS. This was possible due to using an 8-way structure with a high-voltage power supply. 

One of the main functionalities that FiiO is advertising is the new Desktop Mode. Basically, FiiO M23 has two Type-C ports, and one of them is “POWER IN” only. If you’ll plug it into a fast-charging charger, you’re able to unlock the Super High Gain mode. This mode lets you reach up to an impressive 1W into 32oHms, which is plenty for driving all IEMs and even some planar-magnetic headphones. 

While using this mode, the other USB port is available for you to connect to a phone, and use the FiiO M23 as a USB DAC. Talk about convenience.

Another great thing about the Desktop Mode is that when the device is connected to the charger, it’s completely powered by it. This means, that the built-in battery will neither be charged nor discharged, so your battery will stay in pristine condition. With this function, FiiO proves that it really cares about its customers, providing a solution that will let them use their products for longer, without any worries about the battery. Big Kudos to FiiO.

Speaking of battery, reviewed FiiO M23 once again impresses. It has a built-in 5500mAh battery, that supports extreme fast charging. This means, that if your M23 drops to 0%, it only needs about an hour to go up to 80%, and then it slows down to ensure the longevity of the battery. From my experience, these numbers are accurate. Using the M23 in balanced mode (and you certainly want to do so), gets you a battery life of about 9h, and around 10,5h when using single-ended output. While these numbers are pretty standard (not to even mention the legendary battery life of Sony DAPs), the addition to ultra-fast charging makes the battery performance of the new M23 more than good. All you need is just to charge it for 35 minutes to get 50% of the battery, which then lets you use it for about 4.5 hours. 

The new FiiO M23 runs on the 8-core Qualcomm Snapdragon 660 with 4GB of RAM, and Android 10. The system is fast and there’s no lag when using it how it should be used. If you want to play games, just buy yourself a handheld console (I just did myself! Nostalgia attacks when playing Pokemon on the go). When you’re using the M23 as a music player, it operates fast and there are no crashes. FiiO has been manufacturing Android-based DAPs for years now, so they pretty much mastered them when it comes to software.

Speaking of it, you have 6 different modes to choose from. These are Android, Pure Music Mode, AirPlay, USB DAC Mode, Bluetooth Receiving Mode, and Roon Ready. Talk about flexibility.

Of course, FiiO M23 also has built-in two-way Bluetooth with codecs such as LHDC/LDAC, aptX HD, aptX, AAC, and SBC. It also has MQA 8x unfolding. When it comes to supported formats, the M23 does pretty much everything, 384kHz 32bit, native DSD, and even 768kHz 32bit and DSD512 when using its USB output and bypassing the DAC. 

Obviously, we cannot skip things like the 10-band precise PMEQ, which translates to Parametric Equalizer, and ALL TO DSD upsampling. Additionally, you can activate the latter in any operating mode. 

Lastly, let’s talk about DAPS. It consists of both the FiiO-developed HiFi audio core that bypasses the original Android version plus a low-jitter clock co-processor. It avoids audio resampling and provides a high-precision, low-jitter clock no matter if you’re using the FiiO Music app, a third-party app, USB DAC mode, etc. This is meant to provide a unified performance, no matter what app or mode you’re using. 

Sound of the reviewed FiiO M23 

That was a lot to cover, not gonna lie. Now, let’s get into what’s the most important in every single audio device – how it sounds. The FiiO M series has been impressive for years, I had my own, classic M11 years ago and enjoyed it a lot. Michal was highly impressed with the M11 Plus ESS, which he has reviewed here. This means that the reviewed FiiO M23 has a lot to prove to be considered a successful member of the M-series family. Does it succeed?

It definitely does. FiiO M23 offers a highly detailed sound with great resolution, while also sounding natural. It’s not analytical by any means, it’s not sharp, or overly shouty. It sits in the sweet spot between technicality and enjoyment. It definitely has all the technical qualities to back it up, offering a sound that is simply mature, interesting, and fun to listen to. Even when using it with some truly high-end IEMs such as the Fir Audio Krypton 5 or Xenon 6, I never had a feeling that the reviewed FiiO M23 is limiting them by any means. This shows that we’re really speaking of a sound of big caliber.

The bass is agile, fast, punchy, and vivid. It’s definitely on a more controlled sound, as it never bleeds into the mix. The overall bass presentation is all about punch, control, and texture. The amount of bass is also spot-on, delivering a sound that is just natural and lifelike. It doesn’t add anything, nor it takes anything away. This is the type of presentation that we should expect from a good-quality DAP, and the M23 truly doesn’t disappoint in this regard.

Doesn’t matter if you’re listening to some electronic music, an acoustic bass, or metal, the bass of the M23 always keeps up with the pace, but at the same time, it never dominates. It just lets your headphones or IEMs shine, while “only” providing them with a quality signal to utilize. The amount of texture and detail in the bass department are both fantastic, creating a sensation of a bass that “you can touch”. 

A song called Impression I by Lunatic Soul is a good example of how versatile this bass is. It’s firm when it has to, but when the mix changes and low frequencies are meant to be a bit loosen up, the M23 does just that. It doesn’t force anything on the sound, it just analyzes and plays with it. On the other side, “Spiraling” by Edison’s Children has that bass that is definitely on the thicker, more thumbing side, and once again, the M23 doesn’t try to make it controlled. It just sounds how it should, giving you a type of presentation that it was meant to.

The midrange is again, natural, with a hint of softness to it. This is actually my favorite type of midrange delivery, adding that touch of richness and analog vibe to the sound. This makes vocals sound very romantic and natural, especially with male vocalists. 

That added richness ensures that you’re going to enjoy your favorite music, regardless of the mastering quality. Well, the treble does that as well, but more on that in a second. Overall, the timbre of instruments and voices is just right, presenting you with a sound that is uncolored, yet enjoyable and good for long listening sessions. 

Female vocals also sound beautiful, as the reviewed FiiO M23 has a really high resolution, resulting in them sounding vivid and real. The upper midrange is definitely not boosted, but it doesn’t need to be to sound good. Actually, this makes the M23 great for listening for extended periods of time without being tiring. When it comes to details, the FiiO M23 does great in both micro and macro details, providing a sound that is insightful and refined. 

The treble continues on what midrange started. Again, its resolution and detail retrieval are both exceptional, but there’s a hint of smoothness to it. This makes the reviewed FiiO M23 a very universal device when it comes to pairing with IEMs and Headphones, and it’s not prone to sibilance. If you want to have more crunch and vividness, choose a brighter headphone. If you’re sensitive to bright and analytical sound, pairing the M23 with a neutral headphone will make you feel at home.

It’s not just about pairings though. That added richness makes the treble sound just natural. Female vocals, drum cymbals, and acoustic guitar strings all sound rich and thick, but together with M23’s exceptional resolution, it never falls into the “too much” category. It’s just salt and pepper on a good-quality steak. It’s not meant to alter the overall characteristics, rather than just make sure it tastes good – and it does.

The soundstage is open, and airy with a lot of separation. It doesn’t try to mimic a concert hall, it just gives you what’s there in the recording. At the same time, it’s not intimate when it’s not meant to, having a proper scale, depth, and width.

The imaging is perfect with a lot of air between instruments, which, together with a pitch-black background, create a soundstage that sounds “just right”. It’s all down to your headphones of choice. If you want a vast, super open, and huge soundstage in your music, pair the FiiO M23 with a headphone/IEM that sounds like it, and the M23 will deliver, never limiting what’s there.



FiiO M15S

Let’s compare the M23 to its bigger brother, the M15S. Actually, right off the bat, these devices are closer to each other than you might think, as it mainly comes down to preference. 

Of course, the M15S is slightly more nuanced when it comes to technicalities, but the difference is not huge. This is especially impressive about the M23, it has such a high level of performance despite costing significantly less.

So, the biggest difference here is within the sound profile. The M15S is more energetic and in-your-face sounding, while the M23 is smoother and more refined when it comes to timbre.

The bass is slightly thinner on the M15S, but it’s the opposite with the midrange. The M15S has that really forward-sounding, thick midrange that is its main selling point for me personally. The M23 takes a step backward, while still offering a sound that is rich and enjoyable. It’s just more “normal” with its presentation. 

When speaking about power output, both DAPs have plenty to run all IEMs and many headphones, including planar-magnetic ones. Of course, don’t expect driving the HiFiMAN Susvara out of any, but even high-end headphones like the Audeze LCD-5 or Meze Elite are no challenge for both the M15S and M23. The Erzetich Charybdis and HEDDphone One were both pulled back a little bit, but still more than listenable. It’s a portable DAP at the end of the day, and to put it as simple as I can – every headphone that you can imagine bringing outside of your home will be just fine. Super demanding, open-back beasts won’t. 

Choosing between these two is not an easy job. If you value a more universal, neutral-ish presentation and you like as much value as you can get, the M23 is probably your guy. If you prefer more pronounced, stronger sound characteristics and don’t mind spending a bit more, the M15S is a brilliant alternative. 

Cayin N3Ultra

These two devices are vastly different, especially considering their functionality and what they are meant to be. The M23 offers a lot more when it comes to functionality, streaming services support, raw power output, big screen, etc. 

The N3Ultra on the other hand is basically all sound, with its beautiful tube output and a never-seen-before richness in DAPs from this price category. Because of that, let me try and give you just a pure sound comparison and what to expect from both.

I told you already that the M23 is neutral-ish with a hint of richness to it. The N3Ultra is just pure richness. The M23 is more into a detailed, fast, and accurate sound, while the N3Ultra is mellow, beautiful, and warm. The M23 is also capable of driving more demanding headphones, and its background noise is basically non existent. 

At the end of the day, they are meant for completely different users. The M23 gives you more when it comes to functions, universality, and pairing possibilities. The N3Ultra on the other hand, gives you a more unique type of presentation that once you’ll like it…it’s pretty much game over for every other DAP on the planet. 

However, if you’re looking for a one-and-only DAP for your collection and you want to have as much flexibility as possible, the M23 is a better choice here.


As I already stated, the M23 does well with just about everything, apart from super really demanding over-ear headphones. Because of that, I’ll try to stick to a bare minimum when talking about pairings, so as not to confuse you.

Fir Audio Krypton 5

My beloved Krypton 5. To this day, it’s my favorite IEM of all time by some margin. This IEM pairs with the M23 brilliantly, getting all it needs when it comes to detail retrieval, resolution, and overall cleanliness of the signal.

You’ll be getting a sound that is very powerful, bassy, thick in the midrange and delicate, airy on top. A sound that just keeps on going and you keep on enjoying. Beautiful setup, but quite expensive obviously, considering the price of the Krypton 5. 

However, the M23 doesn’t seem to “hold back” this monster of an IEM in any way, which is impressive, considering it costs a fraction of the price of the KR5. Nice.

Campfire Audio Fathom

Now we’re having a more “reasonable” pairing, especially when looking at the prices. Both products have a similar vibe to them – neutral, with a hint of richness. This gives us a setup that is just a pleasure to listen to. You’ll get all the details there are, married with a sound that is easy to listen to, mature, natural, and just enjoyable. 

if you have $2000 burning a hole in your pockets and want a portable setup that does it all and gives you maximum flexibility in both functionality and sound, this is a fantastic pairing that will last you years without even thinking about upgrading. 

Audeze LCD-5

The Audeze LCD-5 is an ultra-accurate sounding planar-magnetic headphone that has the best treble I’ve ever heard in this hobby. This makes it quite demanding when it comes to pairing with the source device, hence I’ve chosen this model for this section.

However, first things first, the FiiO M23 has no problems driving the LCD-5. This headphone scales infinitely with better gear, but the M23 does the job, delicately speaking. 

The sound you’ll be getting out of this combination is incredibly technical, lightning-fast, resolving, and crispy (in a good way). No coloration, no thickness, and no bass boost. Pure technical bliss for all you detail chasers. if that’s your cup of tea, and you’re looking for an affordable-ish DAP to run your LCD-5 from when you’re away from your main rig, the M23 does the job brilliantly. 

HiFiMAN Edition XS

The FiiO M23 is more than capable of driving some planar-magnetic headphones, and it does so with the Edition XS. It’s a great example of what this DAP is capable of. I’m not getting even a hint of “well, that’s too much” from the M23 when powering these headphones, which is impressive.

So, this pairing gives you great dynamics, fast transients, snappy and textured bass, and a lot of details. You basically won’t need a stationary system for your Edition XS if you have the M23, it does the job perfectly.

Maybe you have the Edition XS but you don’t have space for big-boy desktop devices…the FiiO M23 is your solution then. Great pairing.

FiiO M23 – summary

The FiiO M23 is the next iteration to their legendary M series, and it might just be the best one yet. 

The build quality is basically perfect, it looks stunning, has all the functionality you could dream of, and most importantly – it offers a mature, neutral yet rich sound that screams quality. Detail retrieval, resolution, separation, it’s all there. At the same time, its sound is simply enjoyable and easy to listen to.

With all the above there’s only one thing to admit – FiiO once again pulled a banger.


Big thanks to FiiO for providing us with the M23 for this review. I wasn’t paid or asked to say anything good or bad about this product, all of the above is just my personal, unbiased opinion. 

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