FiiO M23

FiiO M23 - A feature rich DAP with desktop level capabilities​

FiiO new M23 DAP is a both natural progression on from the M11 Plus but with the addition of some clever new features the M23 is now blurring the distinction between a portal DAP and a desktop headphone Amplifier



But is a DAP the right device for you? Let’s find out in this review.

Note: I would like to thank FiiO for providing the M23 for the purposes of this review - if you are interested in more information about the M23 check it the details: here

Why use a DAP?​

I have a section later where I explain my own personal history with DAP’s and from that long history, I have derived a bunch of what I feel are key benefits of a DAP, so before getting into this review. Here are my thoughts on why a DAP might be still a relevant device for you.

In my opinion, a DAP has always had 4 ‘core’ requirements:

1. Browse and play my own music, ideally from on-device storage, so I can use it ‘offline’
2. Be portable enough to carry with me ( to places where I cannot get mobile data streaming like an airplane )
3. Play the music in the highest possible quality - even when Smartphones had headphone jacks this was a problem - the Apple Dongle can only go so far
4. Good battery life and the ability to save the battery life of your primary ‘smartphone’ by being a separate device - numerous times over the past 20 years with DAP’s, I have ‘saved’ the battery on my primary smartphone by using an alternative ‘companion’ device for music when on long ‘business’ trips or on holidays

There is also one more requirement that have become more relevant for me in recent years and that is to have a device that doubles as a desktop DAP with enough power for ‘good headphones’. This is because I often work in shared space so having a portable ‘desktop’ amplifier that I can bring to different location but also works with some of my more demanding closed backs gives me a great working experience.

You might still think your Smartphone is enough (and it might be for your specific use-case) but there is also a cost factor involved. This can be either related to the cost of buying the initial storage on your smartphone or the cost of roaming mobile data streaming:

1. Roaming mobile data charges (especially outside Europe) can mean I get charged something like Eur50 for one hour of music streaming from Spotify or Apple Music
2. Buying say 1TB of extra storage upfront with my smartphone can add $200 to the cost of the smartphone

So lets get into the detail on the M23 ..

Retail Box, Unboxing Experience and Hardware​

The FiiO M23 comes with a nice packaging reminiscent of a mobile phone:

The back of the box:



Upon unboxing - in a sleek package that mirrors its premium design:

Contents:​

Inside that box:



you find the M23 DAP itself which comes pre-installed with its protective cover:



Under the M32 you get a microSD removal pin and some sections with manuals and the usb-charger:



Finally, this is everything that is in the box, a USB cable for charging and data transfer, and a user manual that provides essential startup information:

First Impressions and a device tour:​

The M23 has what I would call a ‘chunky but compact’ size, and it is heavier than I would have thought looking at it, with non-stainless steel version coming in over 300g and the stainless steel version which comes in at 390g. My much larger iPhone 15 Pro Max is merely 220g by contrast, but as we will see later in the specification section there is good reasons for this weight and its size means it still fits easily into my pocket and I had zero problems popping into my laptop bag when going to the office.

I like how FiiO not only provided a case for the M23 but shipped with the case on, its weight probably does mean its screen might not survive a fall onto concrete without this protective case.

Let do a little tour around the different connections of the M23:

Headphone jacks​

FiiO dropped the 2.5mm headphone jack which the M11 ‘series’ had, so we get a 4.4mm and 3.5mm headphones jacks:

As you will see later in the specifications, the 4.4mm balanced output can get to a very respectable 1000mw + 1000mw per channel in the ultra-high gain mode and one of the reasons I feel this ‘mobile’ DAP can double as a desktop unit.

The audio hardware behind these headphone jacks is very impressive with FiiO utilising a new THX AAA 78+ headphone amplifier but more on this in the Audio Hardware section later.

Hardware Buttons​

So the hardware buttons on the righthand side of the unit are very useful, with Next, Previous and Play/Pause buttons.



There is also a ‘Hold’ switch and finally the ‘D mode’ switch for the Desktop mode.

The Lock button has some software configuration you will see later on where you can decide to allow some buttons to still be active even with the device is locked.

As for the ‘D Mode’ switch, I will get into this in more detail later but this is a welcome feature and part of the secret of this device being a capable desktop headphone amplifier.

USB and MicroSD connections​

On the bottom of M23, there is the microSD slot which supports up to 2TB of storage. If you read ‘my mini history with DAPs’ later on you will realise that I immediately went out and bought a 512GB microSD and filled it up with a good selection of my ‘offline music’ collection as I love the ability to carry all or most of my music collection offline.



The dual usb-c is another great innovation which I have seen in a few recent FiiO devices. So one is for power only while the other can be both power and data. While this might seem strange there is a clever reason for this, you do not want you mobile phone or even laptop being drained, providing power to the DAP when using this DAP as a usb dongle. So if you have a desktop usb-c cable connected to the power only usb-c you can happily plug your mobile into the other usb-c and the M23 acts like a high quality DAC for the mobile without pulling any power from your mobile.

The other thing of interest with these usb-c connections is when desktop mode is enabled there is another clever feature, the usb-c power connection will provide power but will skip the battery, therefore if you have it in ‘desktop mode’ mostly your battery will not suffer from typical ‘pointless’ charging cycles that cause battery issues long, this should greatly enhance how long the battery lasts in the long term.

Volume slider, Power and Multi-function button​

Finally on the righthand side we the power button, the volume control ‘slider’ and a multi-function button:

You are provided some software configuration around both how the volume control works and the colour of the light (and when it flashes ) around the Power Button. I will shows these options later. The volume slider has a nice tactile feel and will be familar for those with a previous M11 series DAP.

Note: While the multiple function button is both a great option, I do feel FiiO could do a little more with this button. Currently it has the following functions availalbe to be assocated with it:



But, I feel this could be an excellent button to do automation tasks or even to allow the ability to select an application launch with this button or to toggle ‘Roon’ (more on the ‘Roon’ support later on ). For example, I often use PlexAmp on both my Smartphone and portable devices (as an alternative to Roon) and it would be nice to just launch Plexamp with a single hardware button.

Screen, CPU and the internals​

Both the screen and the CPU on the M23 are good for a DAP but are poor compared to your typical smartphone. In fact, I found it interesting that FiiO are using the same CPU the Snapdragon 660 that I was using in my alternative ‘Android’ phone that doubled as my DAP a few years ago, the Xiaomi Redmi Note 7. So I think FiiO might have upgraded the hardware in this release, but I should also say at no point did the software feel ‘sluggish’.

The LCD screen is good quality for the screen size at 1440*720, it is the least you should expect in a 5.5 inch screen - if it was a larger screen I would expect high resolution and again I would have thought FiiO might have switched to an OLED display.

Looking at the overal specifications, it is obvious that FiiO focused more on the Audio hardware which I believe for a DAP is obviously the correct focus but those expecting 2024 smartphone specifications for CPU, memory and screen will be disappointed.

But before we get into the details of Android, let have a look at the audio hardware next.

Audio Hardware​

FiiO provides this nice architecture diagram detailing the full audio path:

DAC:​

Utilizing AKM’s flagship AK4191EQ+AK4499EX DACs, the M23 offers an improved signal-to-noise ratio and much better measurements than its predessors as you will see in the measurement section below. This technology ensures a cleaner sound and higher audio resolution and a very neutral sounding DAP.

Amplification:​

Features a 4-Channel Fully Balanced THX AAA 78+ Headphone Amplifier providing a high power output of 1000mW at 32 Ohms in Super High Gain mode. This setup ensures that the M23 can drive demanding headphones at high volumes without distortion. While not at the flagship power levels of the M17 it does move the bar as to what you should expect from a DAP at this price point.

Sound Profile:​

The M23 delivers a very coherent, neutral tuning with an energetic presentation and excellent bass punch. It remains dead silent across various IEMs but powerful enough with enough headroom for all my planers to get that bass punch, making it versatile for most environments.

Given that the FiiO Equaliser is a key built-in feature, I feel having a neutral tuning is ideal allowing EQ customisation for those you like do like to customise the sound signature.

Android, User Interface and Software Provided​

The M23 was shipped with Android 10, but I believe an upgrade to Android 12 will come in May. I believe this won’t change too much of the User Interface though there is a new ‘material design’ in Android 12 so some of the screenhosts provided in this revew will look different once the Android 12 update is available.

Other key things in Android 12 will be updated Android Security, better notifications and some changes around the media player (though it remains to be seen how FiiO customise the media player experience with the M23 in Android 12).

The M23 includes an online upgrade application which will be useful when this update is available:



In fact during my review - an updated popped up:

Display and OS​

Here is the current ‘About’ screen with some of the software / hardware specifications:

M23 ‘Modes of operation’​

One of the most important configuration options FiiO provides is the ability to run the M23 in different Modes:

Mostly, you will probably run the M23 in ‘Android’ mode and that is what the majority of this Review will show, but the other modes are very nice to have and I did utilise them a few times in the past few weeks.

So, Pure Music mode is a nice option if you just use the FiiO Music application as it effectively launches just that application so there is no distractions or application switching, but you still get access to things like the PEQ filters and the Audio configuration.

With USB DAC mode effectively turn the M23 into a headphone ‘Dongle’ DAC for your laptop or smartphone. The M23 turns into a simple device showing the status of the connection:


And when connected it looks like this - you get the access to up to 384Khz in Usb DAC mode:


With Bluetooth Receiver and Airplay Receiver modes are nice extra are great for situations where you have the M23 setup with ’lineout’ connection into an speaker Amplifier or powered Amplifier and you can ‘cast’ to the M23.

These 3 have a similar UI to the usb-dac mode above when activated, basically the M23 is just waiting to be send a stream via bluetooth or Airplay.

There is another mode of operation, when ‘Roon’ is enabled the M23 Acts as a full “Roon Ready” device. I have a separate section below about ‘Roon’.

Android Audio customisations and settings​

Lets get into some of the customisation FiiO have made for Android with the M23 - since its ‘stock’ Android, I picked some of the main customisation here, so you can see what can be configured especially related to the hardware of M23:

Global Settings​

As you can see launch into further areas of customisation from this screen.

Let’s check out a few examples:

Light Colour customisations​

There is a light surrounding the ‘power’ button and this is how you can configure that light:

Lock screen buttons​

You can configure what hardware buttons are active when the device is locked - very handy when carrying the M23 in your pocket:

Audio Settings:​

Lots of useful options to adjust how the Audio is handled on the M23:



As you can see above, FiiO have moved the Bluetooth settings from the ‘Android Developer’ into a separate menu here, so you do not need to turn on developer settings when you want to configure the default Bluetooth Codecs and its associated settings.

Super Gain Mode:​

I like how when the M23 detects you have the right level of power from your usb-c connection it pops up the following screen (as if you are playing a game and have ‘unlock’ a secret level):



With this mode enabled you have an extra Gain level available:



And as you will see in the measurement section below - this means you can get that desktop level of power from the Balanced output.

FiiO Music Application​

The most important application (especially if you want to use your own music on a microSD card ) is the FiiO Music application. Both the Android Mode and especially if you switch to ‘Pure Music’ mode you will be using FiiO built in Music player.

Though of course you can install whatever your favourite Android Music Application (e.g. Neutron Music Player) or all the main streaming platforms music applications also like Spotify, Apple Music, Tidal, Qobuz etc

I found the FiiO Music application much better than I initially thought, though it does lack a little bit of customisation compared to some other music playing applications. But I was mostly very happy to use it with my offline music collection.

But let’s get into a little bit of detail about the FiiO music application:

It is relatively good at customisation with nice layouts for the different screens:

Note: If you switch to landscape mode in the player:



You get 2 very small VU meters rather than the one.


Once switched to Landscape all other screens will display in landscape mode nicely:

Note: that white area at the top of the screeenshots here are only a sideeffect of taking a screenshot and were not visible when the device was in landscape mode

Music Profile / Settings​

You can see this is where you can ‘scan for music’ so after ou have put your music on a microSD card - with my 512GB card it actually took close to 40 minutes to finish scanning but once it has indexed the music even after restarted the Application would start-up immediately and have access to all previous scannned music.

There is also a DLNA ‘browser’ within this section of the Application and this worked well looking for the many music servers on my network:



There are lots of settings in this section of the application:



Including a section on DLNA transmitting and receiving:



The crazy thing is I am only touching on some of the other capabilities available, there is a ‘Lab’ with some extra new features, there is Car Mode where you get a simplified player when using the M23 in your Car, there track metadata editing features, playlist management etc

FiiO Link Application​

Another nice application that FiiO has provided is the FiiO link application - basically with this enabled on the M23 you can control your music (and settings) from another device i.e. your smartphone (including iPhones) to remotely control the M23. This is extremely handy if you want to leave the M23 connected to an amplifier or powered speakers and control the music playback from your smartphone.



Basically you start the FiiO Link from the above screen, it will be waiting for a connection:



Once you start a FiiO Link client Application on your smartphone you see the M23 and can control the device.

For example via IOS:

FiiO Link ‘client’ on iOS​

Here is how the FiiO link client looks like on iOS:





Some Audio settings are easily changeable remotely:



But the key thing is you get remote control over the M23:



Overall this was a great feature and again as is the theme of this review means the M23 is much more than just a simple DAP it can be used in many flexible ways.

FiiO Equaliser​

I like how FiiO are standardising their Equaliser Application across devices and platforms, so it’s a very familiar experience here to the one you get configuring the EQ for the KA17 with the EQ defaults and 3 ‘spare’ custom profiles to edit yourself and the Advanced button to open up the PEQ capabilities.

There are features I would love added to this equaliser and FiiO have confirmed they are working on some of these features like the ability to export and import PEQ filters (for example, allowing Squig generated EQ filters to be imported here) and much more custom profiles ‘slots’ available as I have lots of EQ settings I would like to store.

I would also love “autoEQ” integrated though that might be harder. One thing I did notice in my testing with bluetooth headphones was the EQ was not applied to the bluetooth audio - though this might change with the Android 12 update.

Here is an example of what editing the PEQ capabilities look like:

FiiO Market AppStore​

As well as supporting Google Play Store the M23 comes with FiiO own ‘AppStore’ the FiiO Market. I imagine in China where I believe there are limitations on the Play Store, this is a key way to download audio applications:

But it is probably less relevant for those who want to stick to Google PlayStore.

Roon Support​

For those who haven’t experienced Roon it is an incredible beautiful Audiophile application that seamlessly integrates your own music collection or your Tidal / Qobuz subscriptions with a massively detailed metadata database providing albums and artist reviews as well as very detailed track information included who played on what track.

Together with all this information roon provides detailed technical information about how your Audio is being played by your hardware and even the ability to add filters for PEQ and other capabilities directly within the one Application.

I believe FiiO got certification for the previous generation of DAP, the M11 Plus and the M23 is currently using that certification to be ‘Roon Ready’:



A Roon Ready device has lots of extra capabilties within Roon e.g. the Audio Path:

Because the M23 is a Roon Ready endpoint you can remotely Cast music from the Roon Application. So when you are using the M23 as a Roon Ready device you do you get a nice album art of what is playing and some sensible controls - but mostly you are controlling the device from Roon itself:



I won’t get into all the details but for me being Roon Ready is another amazingly useful feature of the M23 that sets it apart from other DAPs and even other desktop headphones amplifiers.

Specifications and Measurements​

Output Power:

As you can see there are lots of different output power options depending on whether you are using the balance or single ended outputs and whether desktop mode and super gain is activated and the impedance of your headphones:

So the star of the show here is the Balanced output in Super Gain Mode a 1000mw is excellent for a ‘portal’ device and more typical of a good desktop amplifier. For comparison the M11 Plus provide a max of 660mW + 660mW into 32Ω. But a ‘real’ desktop player like the FiiO R7 provides full desktop power of 3650mW + 3650mW into 32Ω.

I believe this power and the desktop mode that enables this “Super High Gain” mode really allow the M23 to fill a gap for people who want good desktop power but also need a device that is highly portable.

Audio Quality:​

The tonality is neutral with a slight tilt towards a brighter, more energetic signature, which pairs well with warmer sounding IEMs or amplifiers.

Audio Precision Measurements​

Note: These are provided by FiiO, but I thought I would include these 2 in this review for completeness and to give you an idea of how clean the performance of the 3.5mm and balanced outputs are in super high gain mode:

PO Super High Gain Mode 2V@32Ω

BAL PO Super High Gain Mode 4V@32Ω


These measurement show desktop amplifier level of performance - the Balanced output has slightly worse SINAD but this is effectively because of the extra power you are getting.

My personal history with DAP’s​

Feel free to skip this section - this is my personal history with DAP’s but I felt it might give some context to why I still think DAP’s are good even in a world where your Smartphone can ‘do everything’.

So, my first experience with what might be called a DAP was with a Compaq iPaq PocketPC around 2001 - I was working in a company developing stockbroker ‘dealing room’ applications, and we had the idea of a high powered (but expensive) mobile experience might appeal to rich customers, so I got to use and develop for a PocketPC ( Windows CE ) this was also about the time that Napster was starting off and myself and some of my work colleagues were encoding our CD collections with Fraunhofer MP3 encoder. I distinctively remember having about enough space for a single Belle and Sebastian album to be loaded onto my development iPaq and listening to it on a plane with headphones on a trip to London. It was a revelation (this was a few years before the iPod was launched). I immediately went looking for devices with more storage.

Fast-forward a few years, and I had an Archos DAP with a ‘huge’ 10GB HDD and brought this with me on a week-long trip around Germany, the ability to call up any of my 100 CD Collection on its tiny screen was just amazing. I quickly upgraded Creative Zen and ended up with huge by those days collection of 500 CD’s for many other work trips. One key problem with these devices was how slow it was to load the devices with music and once it was loaded how clunky the UI was, but I resisted the temptation of the iPod for a few years.

I remember owning a few other DAP around this time from brands like Meizu which in fairness did start to push better DAC and headphone output with some iPod like touch wheel experience. But eventually I got a job working with a Telco and luckily for me, my job allowed me to experience with the latest phones. I was probably one of the first people in Ireland to have an iPhone and a Nexus device but from a DAP like experience I remember having the opportunity to have both an iPhone 4 and a Samsung Galaxy S1 (where I bought a ‘huge’ 32GB card for storing my music collection).

I flip / flopped between IOS and Android for a few years, typically having a Pixel just for the camera but the reliability and build quality of iPhone meant they were (and still are) my primary phone but had been once Apple removed the headphone jack, I would always have a separate mobile / music device (even a few iPods alone the way), I mostly settled on a few different Xiaomi Redmi mobiles which still had external storage and the headphone jack and were fast enough for browsing my ‘offline’ collection.

The only change I have had in the past few years is in the quality of both the headphones, I now typically bring with me has meant I need a better device for my ‘offline’ music collection and this has lead me to try a few mobile ‘solutions’ over the past few years. While the Apple usb-c dongle is good enough for some headphones, I wanted the ability to have both PEQ and more output power for my headphones and IEM, I initially switched to a Qudelik 5K but a few months ago started using a FiiO KA17 and while both have their pros and cons the fact you still need a ‘device’ with your music and these devices will draw power from your smartphone has brought me back to feeling that a DAP is still the perfect solution.

So, please excuse my personal history with DAPs, but I hope it provided some context for the rest of the review, I will try and make the rest of this review a more visual experience with less text.

Rating:​

I have given the M23 a 4.5 star pragmatic rating, it has a fantastic feature set, obviously built over the years by FiiO on their previous Android DAPs but now with the added Desktop Mode, the extra Super High Gain mode and the upgraded THX amplifier making it a superb offering.

I dropped it 1/2 point as the Android ‘hardware’ i.e. the CPU, Memory and screen resolution are a little out of date ( though the audio hardware is excellent ) and given it currently has Android 10 it currently seems a little date. When the Android 12 upgrade is available i will update this review and I may update the rating at that stage.

Conclusion:​

The FiiO M23 blurs the difference between a portal DAP and a desktop headphone ampiflier and stands out in the mid-to-high-end DAP market through its robust feature set, superior build quality, and exceptional audio performance. It represents a significant sonic upgrade over its predecessors and offers a compelling choice for audiophiles seeking a portable, feature-rich audio device.

The M23’s precise sound signature, coupled with its practical design and connectivity options, makes it a highly recommended purchase for those looking to invest in a high-quality, reliable DAP.

FIIO M23
AK4499 EX + AK4191EQ & THX AAA 78+
$700


Before I start this review, let me thank FIIO for providing the unit in for review, rest assured my review is 100% my own personal opinion.

You can check the M23 here
https://www.fiio.com/m23


Unboxing
What you get inside the box :

• DAP
• Micro SD Ejector
• Included Silicone Case
• USB C to C Cable
• Type C to A Adapter
• Manual & Documents

Build Quality

The M23 screen size is 5.5inch with1440 x 720p resolution, it looks good for a DAP, but not smartphone like good, if you know what I mean.

The M23 comes with a tempered glass screen protector and silicone case pre-applied from the factory.

I believe there are 2 variants of material type for the M23, stainless steel and aluminium one, the one I have right now is the aluminium one.
For the stainless steel version, you get a leather case instead of silicone case.

Left side of the M23 has a touch sensitive volume that can be enabled-disabled and also traditional clicking volume control.

Personally myself disable the touch sensitive one because I don't want to accidentally blast my ears with loud music if I accidentally swipe up the touch sensitive button.

There is also a power button with LED and multifunction button that u can map its function on the left side of the DAP.


On the right side, there is a rewind, play, forward button, Desktop Mode switch and hold / button lock switch.

On the above, there is 4.4mm and 3.5mm port

On the below there is a micro sd slot, USB in and power in port.

For charging, I suggest to use the power in port, because it is more faster compared to the USB in one.

Back side of the M23



Specs

Power & Desktop Mode

with high gain the M23 can give you 475mw @32ohm and 55mw @300ohm, this is actually already quite high power to be honest, but if you really want to push lets say low sensitivity high impedance headphone, you can use the super high gain accessible using the desktop mode, it can provide up to 1000mw @32ohmand 240mw @300ohm, both figures is for the 4.4mm port.

Also desktop mode make it safe to plug your M23 as a desktop unit.
It basically bypass the battery charging system, and completely power the M23 using the power in port, so your battery will be safe.

Battery Life

I get around 9.5 hours of battery life from the 4.4mm port using a planar IEM.
The M23 also supports 30w power delivery charging, it charges quite fast actually to the 80%, around 1 hour.
But 80% above take quite long time.


Input / Mode selection

There is an option for Android Mode, Pure Music Mode, Air Play, USB DAC Mode, Bluetooth Receiving Mode, and Roon Ready.
To be honest with you I rarely touch any mode besides the Android Mode.
Oh also one thing I would like to mention, the M23 can get a bit warm to the touch after several hours of use.

Sound
Neutral – Warm

Bass : Full, Deep, and Well Extended
I felt like the bass has some kind of highlight on its presentation.
It has that dense feeling into it, like there is this weighty feeling to the bass sounds so it renders object very well.

Midrange : Lush, Weighty, Relaxed
The presentation of M23 midrange is just like the typical signature sound of AK4499EX + AK4191EQ implemented on all FIIO's product
Just like Q15, K9 AKM, I praised it because how natural and lush the midrange presentation, and same with the M23, I love it.
It renders midrange in an elegant way, good note weight, lush, and relaxed yet natural, musical and yet very resolving at the same time.

Though if you wanted a more aggressive presentation, the M23 / Q15 / K9 AKM might not be the device for you.

Treble : Smooth, Extended, Very Detailed
The treble presentation of FIIO M23 is smooth, complementing the lush presentation of its midrange, but its extended at the same time, and on top of that, its very resolving and detailed.

There is this airy feeling without making your ears tired, and its very good, It can renders micro decay very well, tested even with planar type IEM / headphones.

Usually planar type IEM / headphones at least for me always has that impression of the decay is very short, but not when plugged in to the M23, it has proper decay of sounds ,and I really love it.

Technicalities
for $700 I'd say its “Very Good”
It offers practically almost the same similar technicalities like the K9 AKM but in portable form factor.

Stage : Very Good
Grand and well rendered layering
It sounds expansive just like a desktop unit for real, I don't know how FIIO made it, but yeah it sounds just as expansive as the K9 AKM.

Imaging : Very Good
It can make my trusty cheap Moondrop Chu 2 sounds holographical, no joke.
It rendered sounds very well with many layered information that you can easily image the sounds.

Detail Retrieval : Very Good
The M23 has a very good detail retrieval on all of its frequency (bass – mids – treble)
It sounds very resolving.
The M23 is really a joy to listen to, it sounds relaxed but full of micro details.

Separation and Positioning : Very Good
Thanks to its grand and well rendered layering of the stage, separation and positioning of the M23 is also very good, you can easily pinpoint and separate whatever you want with this DAP.

So basically for the technicality part, I was mind blown when I first tried the M23, because my expectation the M23 would be like below K9 AKM in terms of technicalities but no, Its so close to each other, yes its that good.

Comparison

FIIO Q15
The Q15 is almost like the M23 without operating system and minus THX AAA 78+ amp.
Is it worth it to spend more and get the M23?
In my opinion YES.

The M23 has superior bass control compared to the Q15.
M23 also has this more weighty presentation of the bass and it help renders object to feel more realistic and natural.
As for technicalities, the M23 also take it to the next level, basically what I said in my K9 AKM review applies here.
Its just like Q15 on a steroid, every aspects of the technicalities is noticeably improved.

Conclusion

If you really like the K9 AKM sound and hoping there is a portable version of it then here is your answer and solution for it.

The FIIO M23 is a device that you really can't underestimate.
It offers decent processor, very good screen, and decent battery life, somewhat updated android OS version and the flexibility of desktop mode.
You can literally use the M23 as a desktop unit too if you wish it for.

I can easily recommend the M23 for its price. Trust me, It offers a very good value without touching the $1000 price point.

Just in case you're Indonesian or understand Bahasa Indonesia, you can watch the M23 review video here



Thanks for reaching this far !

-littlenezt.

The FiiO M23 is the latest DAP from FiiO. With an RRP of €749, it is priced between the M11s and M15s. The M23 not only continues the classic hexagonal honeycomb design and 18:9 format of the M11 series, but also offers significant improvements in configuration, performance and ease of use. The aim was to create a mid- to high-end DAP that offers both outstanding performance and an excellent listening experience.



The M23 uses AKM's flagship AK4191EQ+AK4499EX. FiiO also uses "DWA ROUTING Technology" to further improve the signal-to-noise ratio. This technology enables a cleaner sound background and higher audio resolution, resulting in a more relaxed and natural sound.

The M23 is the first DAP from FiiO with two USB Type-C ports, one of which is dedicated to power input only (POWER IN). When this dedicated USB Type-C power port is connected for fast charging, the Super High Gain mode can be activated for more gain and more output power. In this mode, the output power can be increased up to 1000mW@32Ohm. In normal battery-powered mode, the M23 reaches a maximum power of 475mW@32Ohm, which is still more than enough for all IEMs on the market. Even the FatFreq Grand Maestro can be driven at high volumes. In this mode, the other USB Type-C port consumes no power and is therefore suitable for connecting the M23 to a smartphone for use as a USB DAC.

In addition, the M23 naturally also has the patented desktop mode (D.MODE), which can be activated with a switch. When D.MODE is activated, the M23 is fully powered by an external power source. The built-in battery is not used. It is neither charged nor discharged. A 5500mAH battery is used in the M23. A dual-mode fast charging system combines extremely fast charging and normal fast charging. When the battery is low, extreme fast charging is used to provide a safe charging speed of up to 30W. When the battery is approaching a charge level of approx. 80%, the M23 switches to the somewhat slower fast charging method, which is more gentle on the battery, in order to increase the battery's service life. With this charging method, a completely empty M23 can be charged to a capacity of 80% in approx. 1 hour. In symmetrical mode, a fully charged M23 lasts me just over 8 hours. A very good value!

The M23 uses amplifier designs from THX. These are considered to be particularly clean and linear. The THX AAA 78 headphone amplifiers used in the M11 Plus and M11 Pro have been further improved and implemented in the M23 as THX AAA 78+. This new design enables a more powerful sound reproduction with extreme precision.

Further technical details include the use of the proven Snapdragon 660, 4GB RAM, 64GB ROM, a 5.5-inch display with a resolution of 720x1440 in 18:9 format and 4 gain levels. The M23 will initially be delivered with Android 10, but will be updated to Android 12. The M23 comes with 6 different modes such as Android mode, Pure Music mode, Airplay, USB DAC mode, Bluetooth Receiving mode and Roon Ready mode. An integrated 10-band PEQ can be used in each mode.



The scope of delivery includes a transparent silicone case, a USB cable and instructions. The DAP itself looks very high quality in a great blue design. There are no sharp edges or anything similar and it sits very comfortably in the hand. As I currently use my DX320 MAX Ti almost exclusively, I now realize how big and clunky this iBasso DAP actually is. The M23, on the other hand, is tiny in size and weight and fits easily into any trouser pocket. And it's also great that it has a lock button. How much I wish my MAX Ti had this, because you often reach the buttons unintentionally while wearing it. With the volume control, you have the option of doing this via two buttons, as you would with other DAPs, or via a rectangular touch area on which you can slide a finger up or down to adjust the volume and, depending on how quickly you move your finger, it can be adjusted more quickly than with individual presses. I think the concept is very good!

For the sound test, I initially let the M23 play for 30 hours until it had developed its full potential. In this review, I have selected some of my own consorts for operation and these include: The Austrian Audio Composer, Fir Audio XE6 and 64 Audio Fourte Blanc. I also paired it with the iBasso PB5 Korgtube amp and looked at how the tonality changes. In the past, I have already tested the FiiO top model, the M17, and the M23 is very similar in terms of tonality. It is a rather neutral DAP without any coloration with brighter timbres compared to the DX320 MAX Ti or even a Shanling M8, which has a much warmer sound. The FiiO M17 is a very technical DAP and gets the maximum out of its ESS DACs when it comes to sound precision and separation. The M23 is not quite at this level. However, it also only uses one AKM DAC and is much smaller and much handier. Unfortunately, I don't know the M11s and M15s models and can't make a comparison with them. However, I think that FiiO has classified them correctly in terms of sound and that would be M11s<M23<M15s<M17. It's quite remarkable what you can get these days in terms of sound for the price of €749! An M17 is twice as expensive but never twice as good. The latter still has significantly better reserves for driving a Susvara or Abyss 1266 TC. The M23 can't do that even in desktop mode with the highest gain level. For IEMs, a Composer or a Utopia, however, you don't even need the desktop mode, as these models are easily satisfied with the performance in battery mode. If you are looking for a small and very good-sounding DAP for on the go, the M23 is a better choice than the much larger M17.

Tonally, we are dealing with a neutral DAP with very good technical qualities in terms of detail and separation. Only the significantly more expensive DAPs offer a direct comparison and show that it can be even better. I listened exclusively to the M23 for a few days and didn't really miss anything during this time with my headphones and IEMs. The M23 is an energetic DAP and doesn't have such a romantic character as the Shanling M8, for example, making it a very good combination for the somewhat warmer IEMs such as the XE-6 and Fourte Blanc. Due to the brighter, more energetic presentation, it can also be paired with a warmer amp such as the iBasso PB5, resulting in a slightly brighter timbre overall than when paired with the DX320 MAX Ti. I would no longer recommend the latter combination with an XE-6, for example, as it then becomes a touch too warm. With the XE-6, on the other hand, the M23+PB5 combination works very well! What bothered me a little is that the lineout on the M23 is fixed and doesn't have any gain stages. This means that the PB5 has a little too much power and the volume range is very limited. Of course, you can also go from the headphone out into the PB5 and then have the gain stages available. But this leads to so-called double amping, i.e. the output passes through the amplifier stage as well as the DAC stage and can lead to a loss of sound quality. I also tried this variant and preferred it in the end, as I could not accept the disadvantage of the excessive volume range of the pure lineout. I was happy to accept the very slight loss of sound quality.



From the bass to the treble, there is nothing that stands out in the performance. Everything sounds very balanced. The M23 sounds incredibly clean, which is probably due to its THX amplifiers. A DX320 MAX Ti pulls the sound even further apart with a larger stage. In terms of bass punch, they are almost on a par. The M17 hits a little harder. The mids are designed for maximum separation and detail and are not as full-bodied and natural as the MAX Ti. Here, the M23 has more of a FiiO house sound, just like the M17, i.e. without any warm melting in the mids, absolutely free of coloration. The treble is detailed and free of sibilants. The transition from the mids to the highs is smooth, so that even micro-details are not masked.

The Austrian Audio Composer is known for its energetic playing style. Does it also suit the M23? At first I thought it might be too much of a good thing, but this combination works really well! It's the treble response of the M23 that makes it sound pleasantly smooth but with real drive and punch at the bottom! A pleasure for fast music such as prog or speed metal!

The Fourte Blanc with its more restrained presentation is also brought to life, so to speak, with the M23 and plays a bit more energetically than with the DX320 MAX Ti. Incidentally, the M23 is absolutely dead silent with all my IEMs. And the volume range in low gain is absolutely fabulous! With the Fourte Blanc, my normal volume is between 30-40 in low gain. So you can still make very fine adjustments where I only have a handful of positions available with the potentiometer on the DX320 MAX Ti and often have to make fine adjustments with the digital volume control.

The M23 is the best DAP I've ever heard in the price range up to €749 and I can give it a clear recommendation to buy. Anyone looking for a technically very good, rather bright, neutral DAP without any tonal embellishments and the whole thing in a portable package can buy it without hesitation