FiiO JM21

Introduction

Just because we’re all used to FiiO turning out extensively specified and well-made products without charging an arm and a leg for them, that’s no reason to get blasé about it.

It would be easy to take this JM21 digital audio player for granted on the basis that it’s just FiiO doing what FiiO does – but really, this is a product that in many ways deserves celebrating. Let me explain…

Design

• 121 x 68 x 13mm (HWD)
• 156g
• Aluminium, plastic and glass

The FiiO JM21 is smaller than your average smartphone – which makes a nice change for a product type that often can be so big that the word portable doesn’t automatically apply. And it’s nice and light, too, which means it can easily be carried in a pocket without doing irreparable damage to your tailoring.

A lot of this trimness is thanks to the use of aluminium and plastic for the majority of the chassis. The rear half of the device is made of plastic (nicely patterned plastic at the rear, what’s more), while the top half (which is sky blue to contrast with the back’s silver) is of aluminium. The front is all glass – it’s a 4.7-inch, 750 x 1334 touchscreen that’s bright and responsive.

The top edge of the JM21 is featureless, but the other three sides all have something going on. The left edge features a power on/off button and a volume up/down rocker, along with a little LED tell-tale, and the right edge has play/pause, skip forwards and skip backwards buttons. It also has a slot for a microSD card.

On the bottom there’s a USB-C slot that’s for charging the 2400mAh battery or for data transfer, and a couple of output sockets – one is a hybrid unbalanced 3.5mm/SPDIF output, the other a balanced 4.4mm alternative. 

Specification

• 2 x Cirrus Logic CS43198 DACs
• Balanced and unbalanced headphone sockets
• Bluetooth 5.0 with SBC, AAC, aptX HD, LDAC and LHDC codec support

As I said right at the beginning, it’s easy to take FiiO’s ability to charge relatively little for quite a lot entirely for granted. But the JM21 has a feature-set and specification that honestly makes its £179 asking price look like it might conceivably be a misprint.

It’s fitted with twin Cirrus Logic CS43198 DAC chipsets for compatibility with resolutions up to 32-bit/384kHz and DSD256 when it’s functioning as an audio player. They’re arranged in a fully balanced configuration with their partnering SGM82862 op-amps. The main control, DAC and headphone amp sections are shielded and isolated in their own zones, in a drive to minimise signal interference and cross-talk.

Connect the FiiO to, say,  a laptop via its USB-C socket and it can function as a USB DAC – in this configuration it’s able to deal with 32bit/768kHz and DSD512. Or if you decide to use it as a source connected to a full-size system, a powered speaker or what-have-you, it has three gain settings, each with a different volume curve, to help match its output to the amplification that’s receiving it. ‘LO’ is ideal for use with external amplification, of course, while ‘H’ provides sufficient oomph to power even the most demanding headphones.

Wireless connectivity is available via dual-band Wi-Fi, which means Apple AirPlay and Chromecast are available – and the FiiO is DLNA-compatible too. On top of this, the JM21 is a two-way Bluetooth device that uses the 5.0 version – as a transmitter it’s compatible with SBC, AAC, aptX, aptX HD, LDAC and LHDC codecs, while as a receiver it can handle SBC, AAC and LDAC.

The operating system is a fairly heavily reworked version of Android 13 – the JM21 uses an 8-core version of the Qualcomm Snapdragon 680 processor, which goes a long way to explaining why it’s so rapid in its responses. FiiO is open about how much Android 13 eats into the player’s 3G of RAM, though, and so suggests only downloading music-streaming apps and avoiding any non-essential stuff – and also prompts you to avoid running multiple apps simultaneously.

32G of ROM is another fairly miserly number (but hey, economies have to be made somewhere, right?) and it looks even less impressive when you realise only 22G is usable. The microSD slot will accept cards of up to 2TB, though – and even if you don’t need all that memory, you’ll almost certainly need some. So don’t forget to budget for it.

Use the JM21’s unbalanced output, listen at moderate volume, and the battery should last you over 12 hours between charges – which isn’t bad at all. Even if you listen quite loud via the balanced output, you should get nine hours or so. And should the worst happen, charging from flat to full takes around two hours.

There’s more, inevitably, but despite the fact that the FiiO uses custom crystal oscillators with ceramic gold-plated bases, screened at the femtosecond level to ensure consistent, stable output, or that the player has a proprietary digital audio purification system that separates the main processing module to the co-processing equivalent, I think the broad point is sufficiently made. Here’s a device that couldn’t be any more FiiO in its ‘specification/asking price’ ratio if it tried.

Performance

• Brisk, informative and confident listen in almost every circumstance
• Dynamic, balanced and spacious presentation
• Not super-comfortable at the highest volumes

I’ll start with the only meaningful negative I can find, and then quickly move on – because the FiiO JM21 has way more positives than negatives to discuss.

So if you’re a reckless sort of listener, and you like to dial in as much volume as the JM21 is able to give, you’ll find it a rather shouty, rather two-dimensional listen. In these circumstances, it sounds stressed. So do the sensible thing and turn it down a bit.

Because if you do so, you’ll find the JM21 has the measure of digital audio players that cost twice as much. No matter if you listen to a 320kbps MP3 of Just Like Honey by The Jesus and Mary Chain via the AAC codec, a slightly lossy 24-bit/88.2kHz FLAC file of Doechii’s Denial is a River or a DSD64 file of No Expectations by The Rolling Stones via the 4.4mm balanced output, the FiiO is a balanced, insightful and entertaining listen. It gives every impression of being just as engaged by the music as you are.

Detail levels are high across the board, and the soundstage it creates is so spacious and so well-defined that even the most transient, peripheral details are able to be put into convincing context. Even hectic, element-heavy recordings are laid out in controlled and convincing fashion, with enough elbow-room for each part to do its thing without being impacted on by whatever’s happening around it. But this very pleasant sensation of space doesn’t prevent the JM21 from presenting music as a unified and singular occurrence.

The tonal balance is fractionally on the cooler side of neutral, but it’s convincing nonetheless – and the frequency response is smooth and even-handed from top to bottom. There’s great low-frequency control apparent, so rhythmic expression is never an issue, and the FiiO are as eloquent and revealing through the midrange as the best alternatives at twice the price. They have a well-judged level of bite and attack at the top of the frequency range, and are alert to even the most minor harmonic variations at every point.

Dynamic headroom is impressive, too – when the band (or better yet, the orchestra) shifts into full attack mode and really ramps up the intensity, the JM21 is able to track the changes and make them absolutely obvious. And it’s just as accomplished when it comes to exposing the smaller dynamic variations apparent in, say, an unaccompanied voice or a solo instrument.     

Should you buy it?