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FiiO JM21: One-minute review
If we’ve all come to rely on FiiO for anything, it’s for specification and performance that’s out of proportion with the amount of money it’s asking for a given device. The latest product to demonstrate this happy knack in action is the FiiO JM21 digital audio player.
It’s compact, it’s more than adequately built and finished, it’s specified like a much more expensive device, and it’s simple to set up and use. Battery life is well above average for a product of this type, in much the same way that the price is well below. You can spend getting on for twice as much money on a Sony equivalent and it won’t buy you anything more where the quality of construction or the standard of specification is concerned.
So, does it sit among the best MP3 players on the market? It’s an unequivocal yes from us.
FiiO JM21 review: Price and release date
- Released January 2025
- Priced at $199 / £179 / AU$369 (approx.)
The FiiO JM21 digital audio player was announced at CES 2025 and launched towards the end of January 2025. In the United Kingdom it currently sells for around £179, while in the United States it goes for $199. Customers in Australia are likely to have to part with AU$369 or thereabouts.
FiiO JM21 review: Features
- 2 x Cirrus Logic CS43198 DACs
- Balanced and unbalanced headphone sockets
- Bluetooth 5.0 with SBC, AAC, aptX HD, LDAC and LHDC codec support
You have to hand it to FiiO – it may have set out to produce the most affordable digital audio player it could realistically manage, but that doesn’t mean it’s felt the need to scrimp on the features.
Which means the FiiO JM21 is ready for any eventuality. It’s fitted with twin Cirrus Logic CS43198 DAC chipsets for compatibility with resolutions up to 32bit/384kHz and DSD256, and these are paired with high-performance op-amps in a fully balanced layout. Its main control, DAC and headphone amp sections are shielded and isolated in their own zones in an effort to reduce signal interference and cross-talk.
Wired outputs consist of 3.5mm and balanced 4.4mm headphone sockets – the 3.5mm socket is a hybrid number that can be used as an SPDIF output for use with an external DAC. The USB-C slot that sits between them can be used for data transfer as well as battery-charging and the 2400mAh battery is good for more than 12 hours of playback between charges. That’s as long as you’re using the unbalanced output and not going to town with volume levels, of course.
The JM21 has three ‘gain’ settings, each with a different volume curve. This is especially useful if you intend to use the FiiO as a source hard-wired to an amplifier or a powered speaker – set the output to ‘LO’ and no harm will come to your equipment – and it also means the JM21 should have no problem driving even quite demanding headphones. And if you connect the FiiO to a laptop (for instance) via its USB-C socket, it can function as a USB DAC and enhance your listening pleasure more than somewhat. Used this way, it’s able to deal with 32bit/768kHz and DSD512.
Where wireless connectivity is concerned, the JM21 is both a Bluetooth transmitter and receiver. When it’s sending to headphones, wireless speakers or what-have-you, its Bluetooth 5.0 is compatible with SBC, AAC, aptX HD, LDAC and LHDC codecs. Use it as a receiver and it can deal with SBC, AAC and LDAC. Dual-band Wi-Fi is on board, of course, and the JM21 is DLNA compatible and supports Apple AirPlay, too.
There’s plenty more, from the custom crystal oscillators (with ceramic gold-plated bases) that are screened at the femtosecond level to ensure consistent, stable output to the proprietary ‘digital audio purification’ system that separates the main processing module to the co-processing equivalent. But by now I think the broad point is made: the compact form-factor and relatively low price of the JM21 is not reflected in its specification.
Features score: 5 / 5
FiiO JM21 review: Sound quality
- Open, detailed and composed presentation
- Good tonal balance and a fair amount of dynamism, too
- Not absolutely comfortable at highest volumes
Everything is relative, of course, and everything needs to be put into context, but when you keep the price of the FiiO JM21 uppermost in your mind, it’s hard to find meaningful fault. That doesn’t mean I’m not going to give it a good go, you understand, but between you and me I’m struggling…
No matter if you listen wirelessly via the aptX codec to something like the Bowers & Wilkins Pi6 true wireless in-ears or the Dali IO-8 using aptX HD, using a pair of Sennheiser IE900 connected to the player’s 4.4mm balanced output, or make the FiiO part of a full-size system by connecting it to a Naim Uniti Star using the unbalanced 3.5mm output, it’s a composed, lively and admirably detailed listen. No matter if you listen to a DSD256 file of Mike Oldfield’s Tubular Bells, a 24/96kHz FLAC of When We All Fall Asleep, Where Do We Go? by Billie Eilish or a 16bit/44.1kHz file of De La Soul’s 3 Feet High and Rising, the JM21 doesn’t put a foot wrong. It’s a remarkable little device.
It balances the frequency range really nicely – from the deep and textured low frequencies to the politely shining top end and all points in between, there’s an evenness of emphasis and a lack of choppiness that speaks of a properly sorted player. It hits hard at the bottom end, but with no lack of control: its straight-edged attack means rhythmic expression is confident and convincing. There’s bite and drive at the top end, but it’s composed and never even hints at becoming hard or edgy. And in between, the mid-range is open and revealing, so a vocalist is allowed complete expression of the character and motivations.
The tonal balance is equally well-judged. It’s on the cool side of neutral, but not by very much and not to the detriment of the music it’s playing. Meanwhile, the attention to detail the JM21 demonstrates is really admirable – even those transient details in a recording that are gone almost as soon as they arrive are picked up on and put into appropriate context.
The fact that the FiiO establishes a quite large and easily understood soundstage doesn’t do any harm, either. Even a borderline-chaotic stage like that which Mike Oldfield creates is opened up by the JM21, and the amount of properly defined space it can put between each element of a recording is quite something. There’s plenty of space on the ‘left/right’ axis and even a stab at creating a proper sensation of ‘front/back’, too. Dynamic headroom is considerable, so when a recording indulges in big shifts in intensity or volume, the player has no difficulty in keeping up and making them absolutely apparent.
In fact, as far as I can tell the only way to make the FiiO JM21 sound anything other than entirely comfortable and confident is to wind the volume up towards ‘ill-advised’ levels. When it’s playing at its upper limits, some of the three-dimensionality of its presentation goes astray, dynamic variations become flattened, and the overall sound gets rather shouty. But you should pay attention to your parents/doctor/own common sense – you really shouldn’t be listening at this sort of volume anyway.
Sound quality score: 5 / 5
FiiO JM21 review: Design
- 121 x 68 x 13mm (HxWxD)
- Aluminium and plastic construction
- 156g
You don’t see many ‘two-tone’ digital audio players, do you? The FiiO JM21 is one, though. It’s impeccably built and finished from a combination of high-quality plastic and aluminium, is sky blue on its top half and silver on the bottom. The bottom is quite interestingly textured, too – although you may not get to experience this, as FiiO supplies the player pre-fitted with a protective transparent plastic case.
The top of the machine is basically all touch-screen – it’s a 4.7-inch, 750 x 1334 affair, and it’s big enough and bright enough to display a lot of information without becoming illegible. Despite the relatively large screen, though, at 121 x 68 x 13mm (HxWxD) the JM21 is smaller than even the most compact smartphone, and at 156g it’s no kind of burden to a pocket.
Design score: 5 / 5
FiiO JM21 review: Usability and setup
- Android 13
- 3GB RAM, 32GB ROM (of which 22GB is usable)
- 8-core Qualcomm Snapdragon 680 processor
The FiiO JM21 uses an extensively adapted version of Android 13 as an operating system, and thanks to an 8-core Qualcomm Snapdragon 680 processor it’s fast and stable in operation. FiiO is open enough to acknowledge that Android 13 is fairly memory-hungry, though, and given the JM21 has just 3GB of RAM available (in order to keep both costs down) it suggests only loading those essential music-streaming apps and avoiding peripheral stuff. It also suggests avoiding running multiple apps simultaneously if at all possible.
The 22GB of usable ROM isn’t going to last long, but there’s a microSD card slot on one side of the player – and it can handle memory cards of up to 2TB, which is enough to store all the hi-res stuff you could possibly want to listen to.
Physical controls are arranged on the edge of the player, too. On the left side (as you look at it) there’s a power on/off button with an LED tell-tale just below it. Beneath there is a volume up/down rocker. On the right, meanwhile, there’s play/pause, skip forwards and skip backwards. Everything you need, in other words, and just as reliable and positive in their action as the touchscreen controls are.
Setting up the JM21 is simplicity itself for anyone who’s ever owned a smartphone. Charge the battery (from ‘flat’ to ‘full’ takes around two hours), put the player on your local network, install the apps you need to install (only the essentials, remember), and away you go. I’m struggling to think of how it could be any more straightforward.
Usability and setup score: 5 / 5
FiiO JM21 review: Value
I’ll say it as directly as I can, for the avoidance of doubt: the FiiO JM21 is tremendous value for money, at $199 / £179 / AU$369 (approx.). It’s as well-made and -finished as any sub-£500 digital audio player you care to mention, it’s specified beyond its asking price, and it sounds great when playing at real-world volumes.
Yes, it could do with more internal memory – but then the physical size, as well as the price, would very probably increase. SO make sure to budget for a microSD card of worthwhile capacity – you’ll still be in possession of a great-value portable music player.
Value score: 5 / 5
Should I buy the FiiO JM21?
Buy it if…
Don’t buy it if…
FiiO JM21 review: Also consider
How I tested the FiiO JM21
- Tested for two weeks
- Listened to both streamed and downloaded content
- Tested with both wired and wireless headphones, Bluetooth speaker and amplifier
First things first: I installed the Presto Music and Tidal music streaming service apps via the Google Play store, and I also inserted a 512GB SanDisk microSD card loaded with lots of high-resolution content into the player’s slot.
Then I used a variety of wired and wireless headphones (including, but not limited to, some Sennheiser IE900 in-ear monitors via their 4.4mm socket and a pair of Bowers & Wilkins Px8 connected via Bluetooth), as well as connecting the player to a Bose SoundLink Max Bluetooth speaker and to a full-size stereo system by connecting its 3.5mm output to a line-level input on a Naim Uniti Star amplifier/network streamer.
And at every stage, I listened to lots of different types of music, stored in a number of different file types, and used a variety of Bluetooth codecs when the FiiO was connected wirelessly.
- First reviewed in February 2025
