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 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 complement 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 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 losing 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!