FiiO K3 Review

Today we take a look at a compact DAC with an amplifier from the well-known company FiiO. The company rarely produces such devices, usually preferring portable DACs or players, but they have always had a line of small stationary devices: the E10 and E10K – the predecessors of the K3. FiiO K3 is not a new model, it has been on the market for a long time, at one time it made a tangible breakthrough in the world of portable audio. And today, despite many new models from other manufacturers, FiiO K3 remains a kind of iconic model with excellent performance and a good set of inputs and outputs.


FiiO K3

FiiO K3 comes in a simple white cardboard box, on top – a cover with a DAC image. The package is as simple as possible: two pairs of adhesive feet, USB Type-C cable and the K3 DAC. Of course, you can find fault with the lack of a carrying bag or elastic bands for fastening, but a stationary use scenario hardly requires this.

Design, Features

FiiO K3

The first thing you pay attention to is the size of K3. In the pictures, it does not seem miniature, but in practice, the DAC is 2-3 times smaller than a standard computer mouse. The device itself is made of metal and painted in FiiO’s favorite black color.

FiiO K3

On the front panel there is a volume control wheel, which also performs the function of turning the device on/off. The volume control itself is made using ADC technology: the control is analog, but its data is converted to digital. This scheme allows you to maintain the smoothness of the analog controller with a good separation of digital channels. Under the wheel is a light indicator that glows in different colors depending on the format of the files being played: DSD — green, above 48kHz — yellow, other formats — blue.

FiiO K3

Also front panel audio outputs — the usual 3.5mm mini jack and the balanced 2.5mm. In addition, there are Gain and Bass switches, the first of which is responsible for the power of the amplifier, and the second carefully emphasizes the low frequencies.

FiiO K3

On the back side of the device, all the other interfaces including USB Type-C as a digital input and a set of outputs: digital optical with coaxial (for using the K3 as a USB-to-SPDIF converter) and a linear 3.5mm. A little higher is the lever for switching USB operating modes: 1 for working without drivers, but only with files up to 96 kHz/24 bit, 2 requires driver installation, but is friendly with all files, up to PCM 384 kHz/32 bit and DSD256.

All other parts of the device are free of functional elements: the company logo and the Hi-Res Audio icon are located at the top, and information about certificates and the minimum input current is located at the bottom.


FiiO K3

FiiO K3 have a nice low frequencies with good control and separation. Due to the linearity of the frequency response, some of the tracks we listened to lack a little dynamics, but in other cases the bass shows itself well, showing the desired mass and speed. Also, K3 does not lose ground in classical or chamber music — the instruments are confidently recognized and their character remains.

The main possible complaint about the middle frequencies is the lack of additional emotions, so this is clearly not the best device for those who listen to poorly recorded music based on vocals. Of course, audiophile recordings sound good, but poorly recorded tracks can sometimes make you bored. The rest is excellent detail and authenticity of the instruments with voices, and on decent recordings the device is revealed. The stage is not bad, more than average in both width and depth.

Here we also have a flat frequency response, and some features. The high frequencies are not quantitatively reduced, you will hear them as much as on the recording. If you are not afraid of honest HF, then they will suit you – good detail and attenuation.

In general, we liked the sound of FiiO K3 — we have always been impressed by clean and honest sources that do not bring anything from themselves, leaving the sound changes to the headphones. This DAC may not be suitable for completely emotionless headphones, but in other cases a minimum of influence at high power. The consequence of this is also an excellent genre compatibility, almost all genres turns out to play qualitatively. Also, do not forget the ability to enhance the bass with the appropriate filter from the manufacturer. The switch makes the sound little warmer without turning into a classic drive, which makes it quite applicable.


FiiO K3

Even today, FiiO K3 remains one of the best portable all-in-one solutions. The main advantage of K3 is the presence of a balanced output, with High Gain enabled, it can give a lot of power, while maintaining a compact size. If you plan to use the K3 primarily with full-size headphones, this is an almost non-competitive product. Also, the advantages include a large number of ports and nice design. Note also that the device has a neutral sound color, which for many can be both an advantage and a disadvantage. In our case, this is a definite plus. Great device for reasonable money.

Official site:


Model No.K3
USB Audio ClassUAC1.0 + UAC2.0
Volume KnobADC
Bass Boost0/+6dB
Line Out3.5mm
Headphone Out 13.5mm single-ended output
Headphone Out 22.5mm TRRS balanced output
Coaxial OutRCA for 192kHz, support DSD64 DOP
Optical OutUp to 96kHz 
Audio DACAKM AK4452
Driver OP AMPOPA926×2
Output Power 1
(3.5mm headphone output)
Output Power 2
(2.5mm TRRS balanced headphone output)
Line Level1.9Vrms
Frequency Response20Hz-80kHz
RGB indicator Sample rate ≤ 48kHz  – Blue
Sample rate >48kHz – Yellow
DSD format – Green

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