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FiiO K3 Headphone Amplifier & USB-C DAC Review

  1. Zelda
    Review - FiiO K3
    Written by Zelda
    Published Jun 21, 2019
    Pros - Build quality
    Compact portable design
    2.5mm Balanced headphones output
    Multiple external output
    USB Type-C port
    Sound quality
    Cons - May be too powerful for very sensitive gears (e.g., IEMs)
    REVIEW – FiiO K3 – Portable AMP/DAC


    Website – FiiO

    Official FiiO K3 page



    Price: U$D 110.

    Many thanks to the FiiO team for the K3 review unit.



    The box is the usual one from FiiO, very compact with no fancy design. The included accessories are just the USB cable, Type-C to standard USB A for PC use and a few adhesive pads to hold the device in place.




    The K3 combines sturdy materials into a compact and portable design with a sleek all black finish. The main outer body consists of a single aluminum piece, CNC-machined, anodized and finally sandblasted, that gives a very solid overall build quality and also smooth texture. There are no sharp edges to worry about as the shape is well rounded. Both front and rear panels are also made of aluminum. The K3 device is also lightweight what makes it comfortable to carry around with laptop when traveling.

    For its small size the K3 is well organized with the multiple included inputs and outputs and various switches. The front panel holds the usual standard 3.5mm single ended socket and a balanced 2.5mm one to its left. In the middle there are the 2 switches for Bass and Power gain, and to the right the large digital volume knob that works as power on/off. There is a LED indicator that once the device is on will indicate the different status and change according to the sample rates. The volume knob is supposed to be a new ADC option for the FiiO products, which should solve imbalance issues on lower volumes. It seems to work as advertised, but more importantly, it has a very smooth transition through the digital steps, and also has a good grip.



    The rear panel is more complex with its multiple supported connections. In the middle there is the main USB Type-C port for power and audio data input of the K3. To its left part there is the Line out 3.5mm port to connect speakers or an external amplifier. Moreover, the K3 features optical and coaxial outputs for even a wider variety of external sources. Do note that the supported signal should vary on each output. Lastly, there is a small switch to toggle between USB versions from 2.0 to 1.0. The 1.0 requires no driver installation but it is more limited in terms of audio quality, whereas the 2.0 will support the better quality but may require extra drivers. With Win 10 computers, the driver was installed automatically by the system.

    It is worth mentioning that even though the K3 main purpose is to be used with a computer, it may be also compatible with some portable devices. For instance, it works with the HiBy R6 Pro with its Android 8.1 system and even with a Shanling M5s; however, it didn’t work with the FiiO M6 small player.


    Sound Impressions

    IEMs: final E4000 & E5000, Advanced GT3, Periodic Audio Be & Mg.
    And for 2.5mm balanced output: iBasso IT04 & IT01s, VE Zen 2.
    Headphones (Dynamic): Meze 99 Classics, final Sonorous II.
    Planar drivers: Hifiman Sundara, Sendy Aiva.
    Amp/DAC: xDuoo XP-2, Dragonfly Red.

    For its price, the FiiO K3 DAC is surprisingly very good in sound quality. Putting aside the various line-out options, from both single and balanced ports the sound strikes with high detail and balance for what could be considered just an entry-fi source. Needless to say the sound will depend on the headphones used, but as usual it follows a similar rule with the different pairings.

    With the bass gain off, the K3 offers a rather linear signal with a balanced presentation from lows to highs. It is pretty much transparent and adds almost no coloration to the sound with a kind of cool tonality and very little forward and aggressive touch that still keeps a whole balance. While there is almost no addition in quantities, there are strong improvements in pure quality such as control, precision and overall detail with better and more effortless extension, and of course, plenty of power for such a small device.

    The bass is tighter with better speed and higher control. There is no lift on the mid-bass so it works equally well with either warm/bass oriented or very neutral to brighter gears. Sub bass has a better reach so lower notes have more audible definition on them. The better control also improves the transition to lower mids, for a less bass bleed and cleaner sound overall. Midrange is more resolving and open with more air and sharper separation of instruments. The lack of coloration might turn a bit colder or drier for vocals but then they gain more detail, and while not highlighted they are also less sibilant or edgy on the usual tracks.

    The treble also gains more quality and resolution, though there is bit less natural tonality on it. It seems rather even, if just a bit more emphasized on the lower treble than the upper when using brighter or very neutral headphones, what gives a less extended presentation on the highs; for the price it is not something to even consider as a con. Soundstage is impressive on the K3 with more width and depth, and on a less degree, more height too. Moreover, the sound is more spacious, better layered and dynamic with higher micro detail retrieval.

    The bass boost works well, with about a 6dB gain that technically reaches up to around the 500Hz region fading away on higher frequencies. The boost is well kept on the main bass region with very little effect on the lower mids or rest of the sound without adding any serious warmth to it. With headphones that already arrive with a solid base on their lows the bass gain is not recommended as it would be too much and unnatural. For example, the Periodic Audio Be, final E5000 or even the Meze 99 Classics will get too bassy and overwhelming. On the other hand, it offers more pleasant results with light to slightly north of neutral bass sets; with the final Sonorous II the bass gain is just perfect to achieve a better overall balance.

    In terms of power the K3 is strong enough to drive any efficient gear with no need to turn the high gain and with the volume knob just between 1 to 2 o’clock levels. For low impedance IEMs, with multi-BA or hybrid drivers, like the FLC 8D or IT04, the K3 is more difficult to use; the volume changes can be too high unless reducing the source volume level. With less efficient stuff like the E5000 or E4000 in-ears, the match is excellent. My impressions on the E5000 were already very positive, and the K3 is capable of showing the good characteristics of the E5000 on balance, stage and dynamics.

    The VE Zen 2.0 with the higher 320 ohm of impedance can be driven to a very decent level, but do not expect the best results of more powerful amplifiers in terms of stage and dynamics. For ~150 ohm or less there should be no issues.

    Lastly, the differences from single to the 2.5mm balanced output are as usual. Sound is wider with more balance between lows and highs, more spacious and airy effortless presentation. It also sounds more powerful and just a bit louder in volume, but apart from that there are no changes in the sound signature. Nothing too major but always a good option to have a balanced output included.


    While I have tried several of FiiO sources offers as in portable players and amplifiers, this is the first dedicated DAC I had listened to and easily find the K3 to be another very solid product from the company as an entry-fi DAC. Build quality is excellent and offers multiple output options for further versatility, but even without all that, the sound quality is really good either on single or balanced ends. It offers an affordable and compact solution as an upgrade over the usual computer sound cards with a wide support of audio sample rates.
      RadarJammer, rocksteady65 and volly like this.
  2. Dobrescu George
    Tiny Boom - FiiO K3 DAC/AMP Review
    Written by Dobrescu George
    Published Mar 13, 2019
    Pros - + Friendly Price Point
    + Full Metallic Build
    + Volume Wheel on the frong
    + Clear, Transparent sound
    + Both Single Ended and Balanced Outputs
    + Optical and Coaxial Outputs
    + Works flawlessly with all devices I test it with
    Cons - - Doesn't come with many accessories, no optical or coaxial cables included in the package
    - Doesn't work very well portably, will drain quite a bit of power
    - Bass Boost was better left off most of times
    Tiny Boom - FiiO K3 DAC/AMP Review


    FiiO K3 is a new product from FiiO, a small DAC/AMP to replace their older, yet extremely successful FiiO E10K DAC/AMP. They geared in many new features to K3, including a Type-C USB Port, USB 1.0 and USB 2.0 compatibility, basically driverless operation for Windows, and even a bass and a gain switch, and to not finish the story too early, even a Balanced Output.


    FiiO is really well-known within the audiophile community for always offering very affordable, yet very high-quality products, and K3 is no exception, FiiO being one of the most supportive, friendly and helpful companies out there. If you ever need to make sure you're purchasing your audio gear from the right people, you can totally rely on FiiO, as they're known for making the repair / exchange process hassle-free, if the need is ever to arise for those.

    It should be noted that I have absolutely no affiliation with FiiO, I am not receiving any incentive for this review or to sweeten things out. This review is not sponsored nor has been paid for by FiiO or anyone else. I'd like to thank FiiO for providing the sample for the review. The sample was provided along with FiiO's request for an honest and unbiased review. This review reflects my personal experience with FiiO K3. Every opinion expressed is mine and I stand by it, the purpose of this review is to help those interested in FiiO K3 find their next music companion.

    About me



    First things first, let's get the packaging out of the way:




    FiiO K3 is a very healthily-priced IEM, at 100 USD, so the package isn't expected to be too fancy, but it does include a USB cable, Rubber stickers, 4 of them, 2 pairs, and a USB Type-C cable. This is more than enough to enjoy FiiO K3, and I feel content with the package for the price point.

    The package could have used Optical cables, any 3.5mm to 2XRCA or 3.5mm to 3.5mm line out cables, or a coaxial cables, so if you plan to connect K3 to any other DAC or AMP, you will need to have those interconnects as well.

    What to look in when purchasing a budget-friendly DAC/AMP


    Technical Specifications


    Build Quality/Aesthetics/UI/Firmware

    FiiO K3 is a fully metallic device, with a rounded housing, and with a large volume wheel on the front. The volume wheel is actually a digital control, and it won't cause channel imbalance at low volumes, nor have the issues that can appear with a fully analogic volume pot.


    On the front of K3, you can find the two headphone outputs, one for 2.5 mm balanced headphones, and one for 3.5mm Single Ended headphones. There is a gain, and a bass switch as well.

    At the back, you can find a Line Out, a Switch between USB Audio 1.0 / 2.0, USB Type-C Input, COAX Output, and an optical Output.

    If you connect both the 3.5mm and the 2.5mm headphone outputs, then only the 2.5mm headphone output will keep working. The Optical Output seems to keep working regardless of what is connected otherwise.



    To be honest, I appreciate the inclusion of an Optical Output, since not all computers have an Optical Out, and it could come in really handy when trying to connect a more expensive DAC/AMP to your PC, to avoid the noise of a USB connection, if you're not a fan of USB purifiers and such.

    There is a red glow around the volume wheel, when there are driver issues, and a blue glow when it is working normally, with REDBOOK FLAC files. It also glows green for hi-res files.

    I left the gain on high, as it seems to make music better with virtually all of my headphones, and I left the bass boost on off for most my headphones and IEMs. The Bass boost is pretty clear and doesn't introduce distortions, it is very clean, yet deep, although it also warms the overall sound, not just the bass. The Bass Boost works well if you have a brighter headphone and you want to thicken it up, or warm up its sound.

    The build quality and the design is outstanding, there are no driver issues, and the build quality / aesthetics and firmware all reach a golden level for K3, a truly beautiful and hassle-free device.

    Sound Quality

    The Signature of K3 is a very clean and clear one, very neutral, without any kind of flavour added to the sound. This means that it is also very transparent, making it an excellent little DAC/AMP to pair with most headphones, if you want to hear that headphone or IEM the way it was meant to sound.


    K3 also has enough power to put some punch in any IEM you connect to it, and it does a sweet job even with my Ultrasone Signature DXP, and Meze 99 Classics, not to mention that it can even power HIFIMAN Sundara or FiiO's own FiiO FH5 very well.

    The bass is very deep, and K3 doesn't seem to struggle at all to deliver a deep and punchy bass, even though it is not the most powerful DAC/AMP on the market, having enough speed to be natural, and enough depth as well. The bass is fairly detailed.

    The midrange has a good amount of detail, and for 100 USD, it also has a good instrument separation. The voices seem to be slightly forward, and it is clearly not a laid-back device, having a good amount of texture.


    The treble is extended well, pretty natural, in both speed and texture. It isn't gaudy nor grainy, but it isn't smooth nor rolled off. Basically, a really natural treble presentation.

    The soundstage is fairly good as well, and since we're talking about a 100 USD device, I think the most straightforward device to compare it to is Audirect Beam, which has a wider soundstage, but less depth, FiiO K3 feeling more rounded and deeper.

    All in all, the sonics are what they should be, and much more, for a 100 USD device, FiiO K3 being a good benchmark for other DAPs. Just a good crisp and transparent sound, with a good linearity all over the place, natural speed and natural textures all over the place, and enough power for most IEMs and portable headphones, including some harder-to-drive gems.

    Portable / Desktop Usage

    FiiO K3 is actually designed to be used as a Desktop Device, but it works very well as a portable as well, provided your smartphone / source can give it enough power. FiiO doesn't recommend using it this way, but if you must do it, you should know that it works this way as well.


    Otherwise, as a desktop device, it is fairly small, it looks good on a desk, doesn't take up much space, although if anything is a little disadvantage, it is a little small and lightweight, which means that a thicker / harder cable may lift if off the table.

    The Volume Wheel is large enough, and it has light around it, so you won't miss it, and you should be able to control if fairly well. K3 has enough power for both IEMs, and some good headphones, so you can consider it doing its job fairly well as a desktop device.

    I did strap it to my Xiaomi Mi Max 3, and it does draw some power, but Mi Max 3 is a monster of a smartphone, with a huge battery, and it made K3's portable usage quite fun.

    The cable included in the package is enough to connect K3 to most laptops and computers, so no issues there either.


    K3 seems to be isolated extremely well from USB Noise, even better than some much more expensive DAC/AMPs, which means that you don't need to worry about connecting it to a performant high-end PC which can be quite noisy as far as its USB noise goes.

    All in all, the desktop usage is very good, and so is the portable one, if you decide to go that way.


    Being priced at 100 USD, FiiO K3 has very few direct competitors, but Audirect Beam is a good one, also Cyrus Soundkey being quite similar in terms of pricing. To make 3, I'll add in Shanling M0, which although is a DAP (Digital Audio Player), is priced pretty close to K3.



    FiiO K3 vs Audirect Beam - The first thing you notice is that the beam is much smaller physically, and intended for a portable usage, but it also comes with more cables. Of course, the Beam doesn't have all the inputs and outputs of K3, and you only get one 3.5mm Single Ended Output with the Beam, while you get a 3.5mm Headphone Output, a 2.5mm Balanced Output, a 3.5mm Line Out with K3. You also get a Coaxial and an Optical Output with K3, making it much much more versatile, just lacking in accessories for using those outputs. The USB input is 3.5mm on both K3 and the Beam. In terms of sound, the Beam is warmer, more creamy, less neutral, and K3 has a more neutral overall sound, more natural soundstage, more neutral bass and treble, and better depth / instrument separation. K3 is much harder to use portably though. If you're looking for a portable little DAC/AMP that is very tiny, yet very powerful, with a warmer sound, wide soundstage, and a happy overall tonality, the Beam makes an excellent choice, while if you're looking for a more mature device made mostly for desktop usage, with a more neutral sound, without a color or a tuning of its own, and with a clear window to your music, K3 makes an excellent choice.

    FiiO K3 vs Cyrus Soundkey - Cyrus is actually quite known for their high-end products, and the SoundKey is one of their more entry-level items, but it still is a good competitor for K3. Starting with the package, the SoundKey comes with more accessories, better overall package, although it only has a 3.5mm Single Ended output, where K3 has both a Balanced, Single Ended, and two Digital outputs, and even a Line Out output. It is quite clear which is the more versatile device. K3 is larger though, but has a volume wheel, a bass boost and a gain switch, while SoundKey doesn't have any of those features. On the other hand, The sound alone, from the 3.5mm Single Ended Output, is in favor of the SoundKey, which is also very neutral, but reminds me more of NextDrive SpectraX, SoundKey being more vivid, more dynamic, having the same soundstage width and depth as K3. This being said, K3 is much much much more versatile, and even has a bass boost, and feels more neutral and even less colored than SoundKey. Now, if you're looking for a portable DAC/AMP, something with a really amazing sound, vivid, and detailed, good soundstage, and which is easy to carry around, then you should totally check out the SoundKey from Cyrus Audio, while if you're looking for something for your desktop, something that is really versatile and fun to use, then FiiO K3 should be at the top of your list for its good build quality, versatile usage scenario and good honest sound.

    FiiO K3 vs Shanling M0 - Shanling M0 is a Portable Player, which can read microSD cards, can do a lot of stuff, and even use bluetooth, but it is priced fairly close to K3, having pretty much exactly the same price. This makes the two direct competitors in terms of price, so let's go. The packages are similar between the two, and your decision probably won't be made based on that. The size is smaller for M0, K3 is larger physically. Both device have a volume wheel. K3 is much much more versatile with the inputs and outputs, but M0 can read microSD cards and has a display, which K3 doesn't. Of course, you're probably reading this part of the review, looking for a sonic comparison. M0 is warmer, less detailed, has a smaller soundstage, is more basic in terms of sound, but also smoother and a touch more euphonic. In comparison, K3 is more neutral, more honest, more clean, more transparent, has better treble extension, and much more driving power. Now, if you're looking for a really tiny mini-DAP, then M0 is really an amazing choice, and it has a lot of abilities that K3 doesn't, but if you're looking for a desktop DAC/AMP that can play your hi-res files, has digital outputs, has a Balanced output, and even a Line-Out, you should totally check out K3 from FiiO.


    K3 pairs well with IEMs, and has enough power for most portable headphones, but it isn't made for really hard-to-drive headphones.


    FiiO K3 + FiiO FH5 - FH5 does a great job at being a thick and lush IEM, with an emphasis on the upper midrange and lower treble, K3's very neutral signature actually making FH5 a bit less warm in the bass, which is great for them, and K3's energetic top end also makes FH5 more airy and better extended. I think FiiO really made those two for each other, that's how well they work together.

    FiiO K3 + FiiO F9Pro - This pairing is really sweet sounding, clean and clear, with a good amount of impact and a good treble extension. If anything, I love this pairing, and since you also have Balanced cables in the package of F9Pro, you should totally consider giving K3's Balanced output a go. The sound is generally very neutral, slightly bright, good speed, with a good instrument separation and soundstage. If you want a smoother / warmer / deeper sound, you can always engage the Bass Boost function on K3, and you'll surely be blown away.

    FiiO K3 + Final Audio E5000 - I actually have taken a big liking to E5000, but it requires you to listen loud for it to sound its best, and it is a very warm and lush IEM, K3's very neutral nature actually pairing really well with E5000, and even with E4000. The sound is more crisp, more natural, more detailed and has better air and treble sparkle, than warmer sources do.

    Value and Conclusion

    FiiO K3 has and still is very fun to talk about, recommend, and use, being just the right multi-tool for your desktop, for a really good price. Being priced at 110 USD, it offers one of the largest number of usage scenarios, having optical, coaxial and even line outs, and a 3.5mm Single Ended Headphone Output, and a 2.5mm Balanced Headphone Output.


    This places K3 really high in terms of versatility and abilities, and although it doesn't come with all the interconnects you may need in the package, those are generally easy to find, and I can understand FiiO wanting to keep the package small, as K3 is.

    And for a fully metallic device, with a beautiful blue glow around the volume wheel, FiiO K3 surely does its duty with the build quality well. The firmware is flawless, and I have always been saying this, FiiO makes flawless DAC/AMPs in every way possible, FiiO Q5 being another good example.


    All in all, if you're looking for a clean, crisp, fun and neutral DAC/AMP, with a lot of versatility, both optical and coaxial output, Single Ended and Balanced outputs, and even a Line Out, you should totally check out FiiO K3, as there's none quite like it out there, at least at the moment of writing this review.

    Full Playlist used for this review

    While we listened to considerably more songs than those named in this playlist, those are excellent for identifying certain aspects of the sound, like PRaT, Texturization, Detail, Resolution, Dynamics, Impact, and overall tonality. We recommend trying most of the songs from this playlist, especially if you're searching for new most, most of them being rather catchy.

    Bats - Gamma Ray Burst: Second Date

    Eskimo Callboy - Frances
    Incubus - Summer Romance
    Electric Six - Dager! High Voltage
    Kishida Cult - High School Of The Dead
    Dimmu Borgir - Dimmu Borgir
    Breaking Benjamin - I Will Not Bow
    Thousand Foot Krutch - The Flame In All Of Us
    Gorillaz - Feel Good Inc.
    Infected Mushroom - Song Pong
    Attack Attack - Kissed A Girl
    Doctor P - Bulletproof
    Maximum The Hormone - Rock n Roll Chainsaw
    Rob Zombie - Werewolf, Baby!
    Escape The Fate - Gorgeous Nightmare
    SOAD - Chop Suey
    Ken Ashcorp - Absolute Territory
    Machinae Supremacy - Need For Steve
    Ozzy Osbourne - I Don't Wanna Stop
    Crow'sclaw - Loudness War
    Eminem - Rap God
    Stromae - Humain À L'eau
    Sonata Arctica - My Selene
    Justin Timberlake - Sexy Back
    Metallica - Fuel
    Veil Of Maya - Unbreakable
    Masa Works - Golden Japang
    REOL - Luvoratorrrrry
    Korn - Word Up!
    Papa Roach - ... To be Loved
    Fever The Ghost - Source
    Fall Out Boy - Immortals
    Green Day - Know The Enemy
    Mindless Self Indulgence - London Bridge
    A static Lullaby - Toxic
    Royal Republic - Addictive
    Astronautalis - The River, The Woods
    We Came As Romans - My Love
    Skillet - What I Believe
    Man With A Mission - Smells Like Teen Spirit
    Yasuda Rei - Mirror
    Mojo Juju - Must Be Desire
    Falling Up - Falling In Love
    Manafest - Retro Love
    Rodrigo Y Grabriela - Paris
    Zomboy - Lights Out
    Muse - Resistance
    T.A.T.U & Rammstein - Mosaku
    Grey Daze - Anything, Anything
    Katy Perry - Who Am I Living For
    Maroon 5 - Lucky Strike
    Machinae Supremacy - Killer Instinct
    Pendulum - Propane Nightmares

    I hope my review is helpful to you!


    Contact me!






      rocksteady65 and volly like this.
  3. Wyville
    FiiO K3 USB DAC/Amp - Easy Peasy
    Written by Wyville
    Published Jan 31, 2019
    Pros - Intuitive to use, significant improvement in sound quality over the internal sound of a MacBook Pro, excellent build quality, great value
    Cons - Some sync issues (with older MacBook), slight noise with sensitive IEMs from the 2.5mm balanced out
    FiiO K3

    I would like to thank FiiO for providing me with the K3 USB DAC/Amp in exchange for my honest opinion. No incentive was given for a favourable review.

    FiiO K3 (at a glance)
    • USB-C DAC and headphone amplifier
    • Decoding up to 384kHz/32 bit PCM and native DSD256
    • DAC: AKM AK4452
    • Op amp: 2 x OPA926
    • Low-pass filter: TI OPA1612
    • USB chip: XMOS XUF208
    • USB Audio Class 1.0 and 2.0
    • 3.5mm SE and 2.5mm balanced headphone out
    • 3.5mm line out
    • Coaxial out
    • Optical out
    • ADC volume control
    • Gain and bass switches
    • Output 3.5mm: 220mW(16Ω, high gain)/120mW(32Ω, low gain)
    • Output 2.5mm: 320mW(16Ω, high gain)/200mW(32Ω, low gain)
    • Price: US$109.99


    FiiO is a very well established name among audiophiles the world over. The Chinese company was established in 2007 and has built up a reputation for affordable products with a high value ratio. You pay a budget price and get high quality equipment in return, which I think is why so many audiophiles have cut their teeth on FiiO equipment when they started out in the hobby, with DAPs such as the venerable X1, X3 and X5. By now FiiO has expanded to include higher end products as well, such as the X7 mkII DAP. They also expanded into IEMs where FiiO again look to set the value bar increasingly high, most recently with the release of the FA7 IEMs, where FiiO have made optimal use of 3D printing technology for mass production. This technology can help push down the price and maintain a consistent quality in large batches, as well as some of the other advantages 3D printing brings (e.g. allowing more intricate designs).

    For me it was apparently only a matter of time before I too gravitated towards FiiO. The audiophile bug has well and truly bitten me and I spend a lot of time listening to music, reviewing gear and generally just have something stuck in my ears all day long, be it IEMs or earbuds. The main downside of that, I discovered, is having a DAP (my AK70) with only an 8-10 hour battery life that is impossible to use when charging because of the noise that creates. It could theoretically be used as a USB DAC, but there too I found things to be far from optimal. Since I do a lot of listening behind my desk, I started wondering about a desktop solution. Being an audiophile that quickly escalated into plans for silly expensive equipment I did not have the money, getting that all too familiar look from the missus and seeing her hand slowly reaching for the frying pan.

    So in the interest of self-preservation, I felt it was high time to be sensible and consider an option that would make for a good introduction into desktop gear without breaking the bank. That is also the way I will approach this review. I am very much a music lover and don't generally delve into the technical aspects of the gear, so I am not going to be the right person to compare technical specs. My aim here is to write for those who, like me, want to upgrade their desktop specs in a simple and affordable way. That is what attracted me to the K3. From what I saw the K3 is a tiny and elegant solution that offers FiiO's trademark high value ratio and is intuitive to use. If that does not sound attractive to the desktop solution initiate, I don't know what does. So let's see how it all worked out in practice.

    The packaging of the FiiO K3 is very much a 'no nonsense' affair. It comes in a white box that keeps the DAC/Amp securely in place and added are only the bare essentials such as the data cable, 2 sets of anti-slip pads (only one set pictured, as I had the other set already installed on the K3), a quick start guide and warranty card. Simple, effective and you really don't need all the fluff, especially at this price point.



    Build quality
    The first thing I noticed when I took the K3 out of its box was how solidly it was built. It is a small and light device, but the black CNC'ed aluminium body feels very solid in the hand, not fragile or cheap at all. It looks really quite elegant and I like it sitting next to my MacBook Pro. The switches are quite small, yet easy to reach even with earphones plugged in and they have a nice light 'click' to them when switching, so it does not require a lot of force, nor is it easy to accidentally switch them. The volume wheel that also acts as the 'on/off' switch feels very nice. There is a healthy bit of resistance and a lot of smoothness that helps to make precise volume adjustments easy, even with sensitive IEMs, and avoids accidentally changing the volume if you brush against it. The body is a little light relative to the resistance in the volume wheel, which is placed quite far to one side (right), so with one-finger operation you might end up flipping the K3 rather than turning the volume up (no such issue turning down the volume). When I operate it, I usually just use my thumb on the other side (left) for stability, which I do intuitively anyway and then one finger can easily switch the K3 on and control the volume very precisely.

    On the front we find (from left to right) a 2.5mm balanced out, 3.5mm Single Ended out, bass switch, gain switch and volume wheel. The switches are simple with only two options, low gain or high gain and bass boost on or off. Around the volume wheel is an RGB light indicator that changes colour depending on the sampling rate. Blue light for 44.1 or 48kHz, yellow to indicate above 48kHz and green for DSD. Once I also got a red light, which I suspect was just the K3 telling me I was being an idiot for plugging it into my PS4 (more on that later).


    On the back we find (from left to right) a 3.5mm line out, USB type C port, Coax out and optical out. Above the USB type C port is also a USB mode switch that allows the user to choose either USB Audio Class 1.0 or USB Audio Class 2.0. The difference between the two is that USB Audio Class 1.0 is limited to files up to 24- bit and 96kHz, whereas 2.0 will go up to DSD256 and 384kHz. For Mac OS users it is easy, as Mac supports 2.0 without the need for installing any additional drivers, while Windows users will need to install those. They can be downloaded freely from FiiO's support page: https://fiio.com/supports


    Basically it is as simple as plug-and-play. On my MacBook I did need to go into the System Preferences and indicate in the Sound menu that I wanted my sound through the K3, but that was nothing more than a button click and my Mac instantly recognised the K3.


    The supplied cable is a nice length so that you can move the K3 around your desk and if you have some OCD tendencies like me, loop the cable around the monitor neatly so it is as much out of view as possible. It is also not too long either so that there is no risk of a complete and utter mess of tangled up cables running across the desk somewhere. My OCD thanks you FiiO.

    Once connected there is the choice of 2.5mm balanced or the standard 3.5mm headphone out. I love this option, as most of my cables are terminated in 2.5mm and while I do have adapters, I prefer not to use those. FiiO indicates that the balanced out gets a power boost of around 50%, which might explain why I got a tiny bit of hiss from the balanced out when using my most sensitive IEMs, the Empire Ears Phantom. Mind you, the noise floor is extremely low on the K3 and my Phantom are the only IEMs I have where I can hear a faint hiss. As soon as the music starts to play there is nothing really to notice and switching from balanced to the 3.5mm single ended out also reduces the noise to imperceptible levels. I can't stand hiss, as I find it far too distracting, but have happily used my Phantom from the balanced out. I think that indicates clearly that it is a really very minor issue and some people might not notice it at all.

    Generally speaking the K3 has worked flawlessly. It is very intuitive to connect and there is very little that can go wrong. I have had two issues though. The first was that at one point after having used the K3 for a quite a while and turning the K3 off, my MacBook lost all sound and required a restart for it to come back. I have had similar issues in the past, so it was unlikely a direct cause of the K3 and I have not had it since either. The second issue was that when using the K3 to watch videos on YouTube, the sound sometimes got desynced and the pictures would lag behind the sound. Pausing the video and restarting it got a fast-forward of the images to catch up with the sound again. I find this issue a little baffling, as I could imagine the sound to lag behind a bit (I had that while using the AK70 as a USB DAC) but not the other way around. I have not encountered it without using the K3. With music something similar seemed to happen, like the music was out of sync with itself and had to recompose briefly.

    Arguably the most important bit and one where I have to look at things a little differently from what I usually do. Usually I analyse the sound with the familiar sections such as "bass", "mids" and "treble", but I agree with those who point out that this does not make sense with a DAC/Amp. Only the bass boost does something to the sound, while without it the K3 is ruler flat. That is also something I really like about the K3, that it turns my MacBook into a neutral source, while my AK70 is more warm-natural sounding. The two compliment each other really well.


    The K3 does an excellent job to scale the sound of my Mac. Without it the sound is tinny, thin and quite harsh with all of my IEMs and earbuds. I regularly use my Lyra Collection earbuds for watching YouTube and vocals sound nowhere near what I know the earbuds are capable of. It is always a bit harsh and what is worse is that the volume control on my Mac is horrific, always requiring me to fine tune with the slider in YouTube because the main volume is at its lowest setting. With the K3 the sound matures and notes sound fuller, vocals sound smoother and everything gets more space to breath. There is also much more precise control over the volume level, as the K3's volume wheel is a world apart from what I can do on my Mac.


    When I want to listen to music, my Mac is not really an option. My Phantom sound like the snowing of a TV set and using less sensitive IEMs such as the Dita Fealty is not helping there either because they end up sounding surprisingly harsh. Moving one step up to the 3.5mm single ended out of the K3 is a significant step up. The sound is clean, even with my Phantom, notes sound fuller, the image is more stable, the stage is larger and everything is just really nice crisp and clear. Switching to the 2.5mm balanced out is another step up, although not quite so significant this time. My Phantom get some hiss, but not annoyingly so, and otherwise it is much the same in terms of improvements. Notes sound a bit fuller still, a slightly larger and deeper stage and the image again feels a little more stable. Especially with the Fealty I also noticed that everything started to sound smoother and more refined. Because these are harder to drive dynamic driver IEMs, I thought I would try those on high gain as well, just to see if it made any difference at all and I sensed some added depth to the image and a slight further improvement to the overall smoothness.

    Of course I felt I needed to see how well the K3 stacked up against my (much more expensive) AK70 DAP. Apart from a difference in tone, which is warmer and smoother, the AK70 creates a much more holographic stage with the Phantom and can push the stage of the Fealty even further, especially in terms of depth. The background of the AK70 is absolutely pitch black and more micro details come through, something I notice especially in the texture of violin strings. Even so, the K3 stacks up surprisingly well and I have had no reservation about using it for my reviews. In fact, the neutral tonality is very helpful, as especially the balanced out of my AK70 seems to have a very laid-back treble that has caused some synergy issues in the past where I ended up switching to the SE out. With the K3 there are no such issues, as it is neutral and the SE and balanced out are the same in terms of tonality.

    As I indicated, warmth and impact can be added through the bass switch. To be honest, I only used it once to have a bit of fun, as I found the sound quality of the K3 to be great without adding in the bass. It can be a lot of fun and I can see sense in it if you are watching movies or playing games and want to add some thump to the sound. Speaking of gaming, I did look into the possibility of using the K3 with my PS4 because I would have liked the bass switch for that, but the optical out is... well... and optical "out", not "in". So in my understanding the K3 can transfer a digital signal from a USB source, out of its optical out and into a different DAC (a non-USB DAC), but it cannot receive a digital signal optically. That was a little disappointing, although admittedly it would have only been a fun little extra and not what I was looking for in the K3 in the first place. I guess it is a sign that I should not have given up PC gaming in favour of becoming one of the lowly "console peasants".

    So did the FiiO K3 live up to expectations? Does it offer that high value ratio that FiiO is so well known for? The answer is a resounding 'yes' to both questions. The FiiO K3 is a great performer in a tiny and elegant package that is intuitive to use and has a very palatable price tag (no risk of 'close encounters of the frying pan kind' here). I had some minor issues with desyncing that I suspect have more to do with my Mac's software than the K3 itself, but even so it has been a joy to use and will certainly see continued regular use. I think it is a great solution for anyone looking to upgrade the sound of their computer (Mac or Windows) without the need for opening it up or loosing too much space on their desk. Or indeed, those looking for a solution they can easily take into work and install without having to explain to the boss why you consider "their computer" inadequate for your audiophile needs. Great job FiiO!
      rocksteady65 and FiiO like this.
  4. AvijitSingh
    A Wonderful Product
    Written by AvijitSingh
    Published Jan 25, 2019
    Pros - Price, Type-C, Clean Sound, Plug and Play.
    Cons - Included Cable, No Optical Input.
    Hey everyone,

    Today I will be reviewing the Fiio K3, a new portable DAC&Amp by Fiio. This unit was kindly provided by Fiio for review and I would like to thank Lily, over at Fiio, for this opportunity. SO with that being said, take anything I say with a grain of salt. And if you have a chance, give this unit a try yourself and form your own opinion.

    For the purpose of this review, I compared the K3 to two different portable/Transportable Amp and Dac Combinations – the IFI Micro IDSD BL ($599USD) and the IFI Nano IDSD ($199 USD) – as they were what I had access to at the time of doing the review. I also compared the K3 along with the onboard of my MacBook Pro 2015. The In-Ear Monitors I used were primarily the Campfire Orion, the Oriveti New Primacy and Ear Sonics Velvet V2, just to see how the K3 performed? with different In Ear Monitors . I did my best to match the volume of each product and, since the IFI products did not have a 2.5mm output, the 3.5 was used on all three when doing the comparisons.

    The Songs I Listened to Were:

    · Shiver by Lucy Rose

    · On & On by Joey BadA$$

    · Righteous Minds by Joey BadA$$

    · Time Lapse by Ludovico Einauldi

    · Labyrinth by Mondo Grosso

    · For Now I am Winter by Olafur Arnalds

    · Visions by Vanilla

    · Ambitionz az a Ridah by Tupac

    · Thriller by Michael Jackson

    · Second Hand News by FleetWood Mac

    These songs were 320kps, Flac, and the last 2 DSD files just to cover all of my bases. It is important to note that the zx300 does not fully convert DSD unless you are using the balanced output.

    Unboxing, Packaging, and Build


    The K3 is a very affordable unit with a price tag of $110 USD or $160 CAD, and with such a low price point the packaging is incredibly simple. In the box you will find three things: the User Manual, the K3, and a Type C cable. The build and finish on the K3 are fantastic as it is made up of metal, and has nice soft rounded edges. The digital volume nob is very smooth with a good tactile feel, especially with the knurled finish. Overall the build quality is great. The only issue I had here was not with the unit itself, but the cable that was included in the packaging. In my case, if the cable was touched when the unit was operational and receiving data from the source, it would just stop working all together. It seemed like something had disrupted the signal and I would have to disconnect the cable, turn the unit off and reconnect everything. This issue was resolved by using a different cable – such as a Aukey Type C – and I had no more issues of this type.

    Sound and Comparisons


    Getting into the most important aspect of this review: how the K3 sounds. I personally find it very difficult to just mention how something sounds without having something to compare it against, but I will try and describe how the K3 sounds as best I can.


    The K3 is a very clean sounding device. It provides little to no background noise or hiss. There is a noticeable increase in detail and separation, as well as a touch of warmth with a slight improvement in bass impact; nothing harsh or off putting about the sound. When you switch to the balanced output, I found all of this to be further improved upon such as separation, imaging and more power along with with a touch more forwardness to vocals and a slight widening to the already very good soundstage. At this price, there is very little I could ask more for.

    K3 vs IFI Nano IDSD BL ($110 USD vs. $199 USD)

    The most immediately noticeable thing when I was listening to Thriller by Michael Jackson was that the K3 had a noticeable larger soundstage, while in terms with depth, they were about the same. Vocals on the K3 seemed to be a touch pushed back when listening to something like Shiver by Lucy Rose. Cymbals and strings were a bit more prominent on the K3 due to it having a slightly brighter sound than the Nano. Additionally, the bass boost option is a nice touch that the K3 has over the Nano, but the Nano does bass better than the K3 with slightly better impact and decay. While in comparison the K3 with bass boost on was slightly less controlled, this was especially noticeable when listening to Ambitonz Az A Ridah by Tupac and listening to the bass in Labyrinth by Mondo Grosso. And the Nano also has what I can only describe as a slightly fuller sound to it whereas the K3 is leaner. If we look at the features of both products, the Fiio has a lot more to it with the option of Coax out, Optical out, a USB Type C input, a bass boost option and a balanced input. Whereas the Nano BL on the other-hand provides a digital input, Line Out, two filters, and an IEMatch input, which is an attenuator that adjusts the? OI if am getting that correctly. Overall both products are great. But with a price difference and the feature set of the Fiio being a bit more comprehensive, the K3 is my pick.

    K3 vs. IFI Micro IDSD BL ($110 USD vs. $599 USD)

    This was a very similar experience overall with? the Nano. When listening to Thriller once again, the K3 provides a wider soundstage and field for imaging. The differences in soundstage was especially noticeable with the opening of the song. On the other hand, the Micro provides a smaller soundstage in comparison, but there is a greater sense of depth when listening to the footsteps and the imaging is also more precise. If we move on to bass with Mondo Gross and Tupac, the K3 is out performed here. The bass is better in all regards even with bass boost of the IFI. The K3 produces a less controlled and less refined bass. When listening to Shiver by Lucy Rose, the guitar in the beginning had a greater sense of reverb and body to it that I did not notice with the IFI. The major reason for the price difference comes down each product’s feature set. The IFI Micro provides a significant amount more power, which is something that the K3 will never come close to providing. The IFI also provides the ability to act as a pre-amplifier on-top of the plethora of gain settings. The K3 is a wonderful unit and is something more suited for a budding audiophile. While the IFI does a lot more in every way, it is not something that I need, so I once again would take the K3 over the IFI Micro IDSD BL.

    K3 vs. MacBook Onboard Sound

    This segment will be fairly short, but I think a brief mention is necessary. All the songs previously mentioned were listened to again and I found that the K3 to be a better sounding product on all levels. The K3 provided a greater amount of dynamic range. It was a much cleaner sound with a lack of hiss. The highs were less harsh and relaxed compared to the the Macbook when listening to pop. The K3, with the edition of all of its features, is a good choice if you are considering moving onto something dedicated for music listening or want to experience for yourself if balanced makes a difference.

    Conclusion and Closing


    Overall, I highly endorse the Fiio K3 especially, at its price point. It is a wonderful portable product that can cover the desktop needs of many people. It provides a healthy number of features at its price point without producing a sound that will not bother anyone. It is a very accessible product and is a good item? to begin with if you are interested in getting started on the audiophile journey. The only exception to the great value of the overall package is the shoddy cable provided. Something I would have liked to have seen would have been the ability to power the unit separately and use the optical as an input rather than just as an output.

    If you have a chance to try it, let me know what you think. The last thing I would like to say is enjoy the music and find what makes you happy.
      rocksteady65, rantng and voxie like this.