FiiO K3
Disclaimer
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
Links:
https://www.fiio.com
https://www.facebook.com/FiiOAUDIO/
Preamble
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.
Unboxing
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.
Layout
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
Connecting
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.
Sound
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".
Conclusions
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!