FIIO M23 DAP REVIEW

Fiio is one of the most well-known DAP (Digital Audio Player) manufacturers on the market. Although they have branched out somewhat over the last couple of years, their DAPs have always been a big part of their core product range.  In this review for HiFi PiG, OScar Stewart checks out the FiiO M23 DAP which features the flagship AKM DAC chip alongside THX AAA amplifier modules and costs £649.

BUILD QUALITY AND FEATURES OF THE M23

Over the years Fiio have refined the build quality of their DAPs and it shows. The M23 is beautifully built with an angular aluminium chassis and huge screen which fills the front of the player. On the top you have the 2 headphone outputs (4.4mm balanced and 3.5mm single-ended), both can be set as line-outputs and the 3.5mm output doubles up as a coaxial output too. On the right side you have playback controls along with a lock switch and D-mode switch (this enables desktop mode). On the left side, you have the volume control which has a touch panel you can slide the volume up/down, or you can press each end of the panel to turn the volume up and down via the integrated switches. There is also a power button above the volume slider, this has an LED light around it and you can choose what the colours mean in the menu on the DAP. On the bottom you will find the MicroSD card slot alongside 2 USB-C inputs, the first is your standard charging/media transfer/USB Audio output, the 2^nd port is for charging only with the M23 supporting quick charge up to 30w. One neat build quality feature is that all the connectors are internally reinforced, this ensures longevity for a product that is designed to be used out and about. It comes with a clear silicone case that will offer a certain degree of protection, and there is a more expensive stainless-steel finish M23 that comes with a leather case. 

Feature-wise, a lot of the usability and interface are like my reference player, the M15s, but there are some differences which I’ll try and list here. First off the M23 runs on Android which allows for flexibility and ease of use for those familiar with how Android works, Fiio has bypassed all of the Android audio processing limitations and all the audio goes through a separate clock co-processor before being passed along to the DAC section. The DAC section uses the flagship AKM AK4499EX + AK4191EQ chipset which separates the digital and analogue processing for improved fidelity before passing along to the THX AAA 78+ amplifier section (this is the short version, there is a full flow chart on the main product page). 

There are 4 levels of gain but when using the internal battery the output is limited to 475mw @32Ohms. However, there is a desktop mode which relies on an external power source to be connected to the USB-C charging port – this allows the output power to reach 1000mw @32Ohms for harder-to-drive loads in a desktop setup – it also means the M23 can be connected to a phone at the same time without the phone needing to provide power. On that note the M23 can be used as a standalone pure DAP, a USB DAC, two-way Bluetooth transmitter/receiver, AirPlay receiver, Roon endpoint or standard Android player. 

All of the different sections are separated internally to lower crosstalk and the battery has a stainless steel backplate to aid in cooling when charging. Battery charging can be disabled when it is plugged into a PC or dedicated charger (via the D-mode switch on the side), and this means you can use it as a desktop source without worrying about damaging the battery. The quoted battery life is around 9hrs using the balanced output or 10.5hrs using single-ended, a 35 minute fast charge should give you over 50% battery life for minimal downtime. 

It has all the usual gubbins of high-res audio support and you can install streaming apps for use over WiFi / offline downloads. There is a proper 10-band PEQ that can be used system-wide (no matter the mode), and both LDAC and aptX HD are supported for high-quality Bluetooth. All in all, it has all the features you could need for a good DAP with some handy little extras (like desktop mode for battery health).

In use, I found the M23 to be a very easy-to-use DAP that was intuitive and snappy in terms of navigation and the buttons are well laid out. I did notice that it does get a little warm when tucked away in your pocket but this is quite normal for a DAP of this calibre and it never got “hot.” 

SOUND QUALITY

I have been using the M23 as my daily DAP for a few weeks now and have had a chance to get to grips with it both functionally and sonically. A couple of things stand out to me; firstly, the M23 is an excellent DAP for the price – it really does offer up superb sound quality and DAPs have come a long way over the last 10 years or so. Secondly, if you find ESS-equipped DAPs to be a little clinical then the M23 might be just right for you as it isn’t “coloured” per se, it just has that ever so slightly neutral-warm tilt to the sound that gives it a little fullness. 

Starting with a nice easy-to-drive earphone, the new Meze Alba. This is a brilliant match in my opinion. The Alba has a nice clean sound and pairing them with the M23 injects a little fullness without taking away from the technicalities. The XX – Missing came on and in the quiet of a home environment the sub-bass is tactile and controlled, the mid-bass has punch and body, whilst vocals cut through with clarity and openness. As this track picks up the M23 / Alba combo manages to separate all the elements with ease, with a snappy yet full-bodied presentation that highlights the qualities of this pairing. 

Moving on to the Westone MACH80. Here you get all the clarity and openness that this earphone has to offer with great depth and control. The M23 has great grip over the sound of these headphones and they may be slightly more detailed on the M15s DAP, however, there is a hint more body with the M23 that takes the edge off sharper notes.

Opeth – Atonement / Reverie has excellent space around individual instruments, the guitars coming out of a black background whilst the cymbals are crisp without a hint of brightness. Everything is exceptionally well placed within the soundstage, and that is a point I will elaborate on – the M23 has quite a holographic portrayal with good headphones and recordings. It projects the sound in a 3D way with convincing depth, width, and height – it is not a closed-in sounding DAP at all. This song with these earphones is another excellent example of what the M23 can do, it doesn’t hold back the sound in the slightest, the bass is articulate and full whilst finer details are easily audible, and all the little sounds are so easily placed within the soundstage. 

On to some full-size headphones in the shape of the Meze 109 Pro which are quite easy to drive. Paramore – Playing God is a punchy and fun song to bob along to and once again the M23 showed off the articulate and engaging bass response without masking the midrange or treble. Hayley’s vocals sound natural and unforced, whilst the treble extends well without any harshness. The 109 Pro can be very slightly treble-happy with some sources but the M23 has a good grip over them and doesn’t allow them to stray into sounding bright. With these headphones in use, I plugged in a fast charger and put the M23 into desktop mode with super-high gain enabled. It didn’t make a huge difference, however, I did notice a little more control in the bass which made the sound a little more linear, it is a small difference though with these particular headphones. 

Whilst in super-high gain mode I tested the M23 with Fiio’s own FT5 planar headphones (with leatherette earpads). Honestly, you don’t need a desktop source when it comes to driving headphones like these and, normally I am an advocate for desktop gear with planars. It’s a combination of the easier-to-drive diaphragm alongside the output power of the M23 in desktop mode that makes this pairing work really well. Linkin Park – Halfway Right, Chester’s vocals come across with nuance whilst the underlying bass beat has depth and impact. The fullness of the sound coming out of a portable player (ok, it is in desktop mode) is quite something, if you don’t have headphones that are too taxing then a DAP like this is all you need for excellent sound out of all sources. 

One last thing – the M15s truly is an excellent reference player and has a higher spec and more output power than the M23, however, for most people’s uses the M23 makes more sense as an everyday DAP. I love the flexibility of the M15s, and its reference sound, it is perfect for taking to shows to demo equipment, yet I would be extremely content with the M23 as a daily portable player.

QUIBBLES

I would have liked to see the leather case included with the aluminium finish of this DAP, not only the Stainless-Steel version. 

CONCLUSION

Fiio have once again shown that they know how to make an excellent DAP! The M23 has a neutral-warm tuning that adds a hint of body and smooths off the edges of the sharpest of notes. The build quality is excellent, it’s easy to use and navigate and has a ton of features that are quite handy for different use cases. Desktop mode means that you don’t need a desktop DAC/Amp for your favourite earphones/easier-to-drive headphones, it is impressive how good this sounds with full-size headphones in this mode. 

The sound is detailed yet natural and there is a hint of warmth whilst having excellent 3D sound staging and separation. I honestly cannot fault the M23 in its execution, it does everything a good DAP should and more, all for a reasonable price. 

AT A GLANCE

Build Quality And Features:

Solid build quality

Feature packed as always

So many functions

Sound Quality:

Smooth yet incredibly detailed and open

Powerful output means it drives most headphones in one mode or another

Value For Money:

Brilliant value for what you get, it can be used on the go or in desktop mode

We Loved:

The UI is easy to navigate and the sound is simply excellent for the money

So many useful features, some you will use more than others

We Didn’t Love So Much:

Lack of a high-quality case with the standard aluminium finish model

Elevator Pitch Review: In my opinion, the M23 is probably the best all-round DAP on the market. It’s the right size for a daily player yet has more than enough power for many full-size headphones. It’s easy to use and the sound has just the right tonality to not become fatiguing during long listening sessions, it really is a superb portable player. 

Price: £649

Oscar Stewart

SUPPLIED BY FIIO

SUPPLIED SPECIFICATION

• Weight 299
• Dimensions (HxWxD) 1365 x 757 x 181 mm
• DAC Chip AKM AK4191EQ + AKM AK4499EX
• Battery 5500mAh
• Sample rate up to 384kHz/24-Bit, Native DSD256
• Operating system Android 12
• Amp THX AAA-78+ (x 2)
• Power output 1000mW @32Ω, 236mW @300Ω
• Built-in Memory 64GB
• External memory Yes (Up to 2TB)
• Operating system Android 12
• Display 5.5″ 720 x 1440 (18:9 Ratio)
• Inputs/Outputs Analog outputs
• 1x 3.5mm (Headphones/Line-Out) 1x 4.4mm (Headphones/Line-Out)
• Digital outputs 1x Coaxial Output
• Supported audio formats Wired and wifi
• DSD64/128/256 | DXD | APE FAST/High/Normal | APE Extra High | APE Insane | Apple Lossless | AIFF | FLAC | WAV | WMA LOSSLESS | MP3 | OGG | WMA | AAC
• Bluetooth SBC, AAC, aptX, aptX HD, aptX LL, aptX Adaptive, LDAC
• Connectivity Wi-Fi, Bluetooth 5.0