Home Dacs & Amps Fiio K3 DAC and AMP reivew — great and affordable

Fiio K3 DAC and AMP reivew — great and affordable

by Paul Dmitryev

Former desktop solution form FiiO – E10K – has been released in the year of 2014 and has never been modified since. And why should one modify what works good? However, the technology marches forward and after almost 5 years here comes the successor that has been named K3.

Inside the newcomer looks rather similar to another FiiO hit – Q1 Mk2 that has conquered the hearts of many supporters. As always, for $100 price the developers have tried to give their maximum. Here you get a hybrid volume control, when the impedance of the volume regulator is transformed into digital form and is used for volume control, the USB Audio switch and the balanced output for those who need more power. Those are not the only new things in K3, but let us discuss it further in a review.


  • DAC: AKM AK4452
  • OPA: OPA1612 + 2 × OPA926
  • USB: XMOS XUF208
  • Frequencies: 20 Hz – 80 kHz
  • Output power (@ 32Ω): 120 mWt single ended, 200 mWt balanced
  • Total harmonic distortion and noise: ≤0.004%
  • Output impedance: <1.04Ω
  • Signal/noise ration: ≥113 дБ
  • Channel separation: ≥70 дБ
  • Maximum output voltage: 7.39 Vp-p
  • Maximum output current: 81.6 мА
  • Recommended impedance load: 16Ω ~ 150Ω
  • Maximum resolution: до 384 кГц/32 бит, DSD256
  • Input: USB-C
  • Outputs: coaxial, optical, 3,5mm headphone, 2,5mm balanced
  • Dimensions: 70 mm × 58 mm × 22 mm
  • Weight: 82 g.

Packaging and accessories

Here we see a simple cardboard packaging of white color and inside, as expected, one more box made of more thick cardboard. The accessories are as follows:

  • K3 itself
  • USB-C cable
  • long sticky “legs” made of resin

At first I wanted to say that the accessories set is really scarce, but then realized that don’t know what might be added here.

Design and controls

FiiO has re-designed their desktop oriented devices again, and this time the DAC has a parrallelepiped form with rounded edges. Personally I prefer rectangular forms, but for this price region I think it is not relevant. The body of DAC is traditionally made of black aluminum and as always all the control elements are located on the front and back panels of the device.

On the front panel there are two headphone outputs, regular 3,5 mm and balanced. The latter is traditionally made 2,5mm however I think FiiO should have considered a switch to Pentaconn. Nearby we can see gain switcher, bass enhancer (traditional slight up of the lowest bass) and volume regulator that also serves as on-off switch. The switch itself looks really good: it sports diagonal cutting and brand red ring. K3 has a hybrid volume control, so you won’t find any noise or channel imbalance. The volume regulator slightly hides the multicolor indicator of on-off positions and signal quality. When the resolution of played file is lower than 48 kHz it is blue, and when it is higher – yellow. When playing DSD files, you get green indicator. The light is not too bright so it does not irritate.

On the back panel of the DAC there are other connectors – line out, USB-in (now USB-C), optical and coaxial outputs and USB Audio standard switcher. It is a great finding, by the way: you may turn the first revision on and use K3 without any drivers with resolution up to 96 kHz/24 bit. Also this version is better compatible with smartphones and works almost without latency, and this is good for watching video. If you need higher resolution and DSD, you may switch to UAC2, but in this case Windows users will require drivers. As you can understand from the output selection, K3 can also work as USB converter for old DACs without USB input.

The build quality is very good, no noise from elements or any problems. Slight concern is the low weight of device. When the cables are heavier it can easily move around the table, but anyway this is what resin “legs” are for.


The following devices have been used for critical listening: iBasso IT04, Meze Empyrean, Audio Zenith PMx2, Noble Kaiser Encore, Campfire Audio Andromeda and Solaris, Unique Melody Mason V3, HUM Pristine and others.

Upon the whole the K3 sound in general is close to Q1 Mk2 and this is not surprising, as similar circuit designs have been used. The main difference is the absence of battery in K3 and its higher power. FiiO K3 sounds neutral with slightly increased weight in bass.

Bass is well controlled within all its length and has enough depth and resolution (of course if you don’t compare it to expensive desktop rigs). The lows cope well with their main task, i.e. playing the lower register of instruments, and bring weight to general sound presence. Those who love accentuated lows will surely like bass boost feature that carefully adds 6dB right before 100 Hz region. This brings some  grandeur, however the presence of this effect highly depends on headphones used and genre of music played.

Mids are sounding neutral, they are not colored, so on bad recordings K3 may sound as lacking emotions, but it is not the device’s fault. When the tracks are recorded good K3 does them justice by playing in natural manner, having good resolution, as well as micro and macro details. The soundstage is a little larger than average, instrument positioning is correct in terms of width and depth.

Highs have normal length and are very well controlled. They are not sharp but of course FiiO doesn’t try to smooth them in order to get more comfortable presentation. The layering is rather primitive but you really cannot expect more from this price. Attacks and decays are well played.

In comparison I limited myself to the devices of the similar form-factors and price, which means a couple of gadgets of FiiO itself.

FiiO Q1 Mk2 As I have already mentioned, the general presentation is similar, but K3 has more power and you can really feel it. There is better bass control, the sound is more dynamic and the high impedance headphones feel themselves more comfortable.

FiiO E10K In this comparison you can easily see the step forward. The K3 has more natural presentation and better sound on both sides of frequency.


Of course K3 is not super powerful and cannot drive hard isodynamic headphones, but it drives everything that it should according to its specifications.  It is also good with sensitive IEMs with very light background hiss, if any.

K3 is not sensitive to music genres but you should understand that it is a lower segment device and one should purchase a higher-end DAC/Amp to get the maximum out of complex music. However even in this case K3 shows itself good. It is relatively sensitive to record quality – 7 out of 10 approximately.

Traditionally, several tracks as example

Dream Theater — I Walk Beside You Even if Dream Theater decides to write almost pop-rock blockbuster, they make it better than 99% of other groups. This track demonstrates technical ability and emotions of FiiO K3.

The Cinematic Orchestra — Electric Counterpoint

I don’t know who called this genre “minimalist” but this hit played by Cinematic Orchestra is a hard task for any source due to presence of penetrative guitars and overall saturation of this track. New FiiO DAC sounds not ideal, but on rather high level.

Brhams — Symphony No.3 In F, Op.90 : 3. Poco allegretto It is one of the most successful combinations in world symphonic music, particularly alchemical marriage of Herbert von Karajan and Berliner Philarmoniker. Peculiar manner of this conductor is very suitable for the Symphony 3 by  Brahms. Of course, the low-budget K3 is not an ideal source for this complex symphonic music, but it is rather enough for making listener feel the concert atmosphere.


The update is here, FiiO may now relax and take a deep breath for several years to come. In contrast to dynamic and fast evolving DAP and headphone market, on-budget desktop DACs do not evolve at the same pace and K3 will surely be one of the leaders.

Translated by Vadim Kolchev

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