FiiO M15 review

FiiO’s flagship portable music player delivers a premium sound Tested at £1176 / $1280 / AU$2399

FiiO M15 review
(Image: © FiiO)

What Hi-Fi? Verdict

The M15 is a compellingly clear and precise portable music player, but it isn’t the most rhythmically adept available


  • +

    Clear and precise sound

  • +

    Polished design

  • +

    Vast file support


  • -

    Presentation lacks energy

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Portable music players are no longer all the rage, as shown by slimmed-down Apple iPod and Sony Walkman offerings in recent years. But for those who want high-quality music on the move, or even at home, a PMP may still be the answer. For all their multitasking magnificence, even the best smartphones can't offer that.

Chinese manufacturer FiiO’s line-up of PMPs starts with the modest M3, but its flagship M15 model on test here is the pinnacle of the company’s technological achievement. We’re talking top-of-the-line components and premium features – a superior music package to any smartphone or more budget dedicated player.


Fiio M15 features

(Image credit: FiiO)

The M15 has a dual configuration of AK4499 digital-to-analogue chips, bolstered by FiiO’s third-generation FPGA (field-programmable gate array) circuitry that promises more accurate clocking and reduced jitter.

Not only does that DAC claim an impressive signal-to-noise ratio of 140dB, it is also capable of natively playing PCM files up to 32-bit/768kHz as well as DSD512 and MQA tracks, which means you’ll more or less be able to play anything through it.

Fiio M15 tech spec

(Image credit: FiiO)

Outputs 2.5mm, 3.5mm or 4.4mm jacks

Bluetooth version aptX HD

Music formats 32-bit/768kHz, DSD512, MQA


AirPlay Yes

Battery life 15 hours

Weight 300g

You can access locally stored music (there’s 64GB storage onboard, expandable by 2TB via a microSD card), in addition to networked music over DLNA. This music can be wirelessly streamed to Bluetooth headphones (up to aptX HD quality) and AirPlay devices. 

You can also listen through wired headphones connected to either of the M15’s two balanced outputs (2.5mm and 4.4mm Pentaconn) as well as the more conventional 3.5mm jack.

FiiO has implemented ‘active servo power’ technology to the M15’s final amplification stage, allowing the power output to automatically adjust according to the headphones used. With earbuds, the M15’s output can be optimised for minimal noise, while for harder to drive headphones, Big Driver mode can be enabled.

Select ‘USB DAC Mode’ from the Android interface’s pull-down menu, and the M15 can also act as a DAC for your computer – becoming a middle man between it and your headphones and enhancing the quality of audio playback. 

‘Android Mode’ mirrors the familiar Android phone interface, allowing users to open a browser or tool (such as the clock) and download music apps, such as Spotify, Tidal, Amazon Music, Deezer and TuneIn Radio, providing the FiiO is connected to a wi-fi network.


FiiO M15 build

(Image credit: FiiO)

Returning to ‘Pure Music Mode’ restricts the player’s functionality to the dedicated music player, which is logical to navigate. Album art is displayed and headers for artists, songs, albums and genres means browsing is quick and simple.

If your FiiO is being used as a source connected directly to your hi-fi system, you can use FiiO’s Link feature to browse and control the M15 from the FiiO Music app on your phone. Reducing the 5.15in screen time is one way to extend the M15’s battery life, which is otherwise a reasonable 15 hours of playtime from a single charge.

For on-the-go use, though, the FiiO is practical to use and hold. Roughly the proportions of a phone, but thicker, the M15 has ergonomically friendly curves and a pleasingly tactile volume dial on the top panel that is easily accessible in a natural hand position. 

The gold-plated rings around each of the top-panel's headphone sockets work with the solidly made, hefty casework to give the player a reassuring sense of luxury, too.


FiiO M15 sound

(Image credit: FiiO)

As you’d expect of a dedicated player at this price, the M15’s sound immediately gives off a sense of maturity. Its expansive soundstage, which allows music a natural spaciousness, is peppered with clear, precise detail and a good supply of punch.

Michael Jackson’s P.Y.T sounds rock-solid: the electric keyboard, guitars and cymbals sound clear and confident while the jaunty bass line drives the track. The FiiO’s rendition is effortlessly articulate and exact in the way it presents the production’s multiple-layered complexity so that each instrument gets its fair due. Playing Olafur Arnalds’ Four, the M15 communicates the dynamic ebbs and flows of the piano piece well.

Though this player will appeal to those who prioritise detail and clarity, in some ways, that compromises its potential to outright entertain. The Astell & Kern A&norma SR25, which costs half the price of the FiiO, exercises a tighter hold over rhythms and has an upbeat energy that the M15 tends to curb. With upbeat and rhythmic tracks, such as Elvis Costello’s Lipstick Vogue, the A&K player comes out on top.


The FiiO M15 isn’t the perfect all-rounder, yet it comes close – only a slight lack of get up and go prevents it from getting a fifth star. It is appealing to listen to, use and look at, and further benefits from extra networked features. For anyone who values crystal clear sound above all else, the M15 deserves to make your shortlist at least.


  • Sound 4
  • Feature 5
  • Build 5


Best portable music players 2020

Read our FiiO M3 review

Read our Astell & Kern A&norma SR25 review

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What Hi-Fi?, founded in 1976, is the world's leading independent guide to buying and owning hi-fi and home entertainment products. Our comprehensive tests help you buy the very best for your money, with our advice sections giving you step-by-step information on how to get even more from your music and movies. Everything is tested by our dedicated team of in-house reviewers in our custom-built test rooms in London, Reading and Bath. Our coveted five-star rating and Awards are recognised all over the world as the ultimate seal of approval, so you can buy with absolute confidence.

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