For the purpose of this review I used my computer as the main setup, plugged in USB in USB 2.0 mode. 50% Aimp3 with FLAC files, 50% Spotify in high quality streaming.
The headphones ? Onkyo IE-C3 (incredibly sensitive to hiss), Sennheiser HD-800 (magic headphone but a bit tough to drive), Meze Empyrean (for the pleasure) and the Audio-Technica MSR7 (because I like it)
Good news, the FiiO K3 is a real upgrade from the FiiO E10K. That, of course, is a minimum after four years in the making but it could have been a simple visual revamp. The sound stage is even more precise, gone is the massive yet strange presentation that could occur with the first gen FiiO E10. It’s not as accurate as the FiiO Q5 but there is something much more enjoyable in the sound, a lovely grain that reminds of the IFI iDSD Nano, but better.
The volume knob begins at 9 O’clock and ends at 6 O’clock, but from 9 to 1 the volume is too low to be really usable. I found my sweet spot from 1 to 3 o’clock, after that it gets way too loud for my Onkyo CIEM, even more in Balanced mode.
With all the headphones, except the Onkyo, the FiiO K3 was dead silent. If this is an issue, I’d advise you to stay in single-ended as the balanced output offers more hiss than the others. Once you hear it, it will be inaudible, but better be prepared than sorry.
The bass boost works pretty well, it adds a 6db on the whole bass section from 20Hz to 100Hz. Then there’s a slow roll-off from 100Hz to 2kHz, the rest of the frequency chart remaining untouched. It’s a bit muddy if you rely on it too much, but on thin sounding headphones like the Sennheiser HD800, it’s really interesting. Sure, you could just get a more powerful headphone amplifier, but that’s also more expensive.
Power and drive
Speaking of power, I was afraid the FiiO K3 would not have enough power to correctly drive a good pair of headphones. Strangely… it worked well, even with planar headphones like the Empyrean or my old Audeze EL-8C.
You need to put the K3 in high gain and turn the volume up to 70%, but it works ! There was no distortion whatsoever and the sound is still loud enough to enjoy your music with a small setup. Don’t get me wrong there, it’s not magical and you can clearly hear some limitations with high-end gear.
Keep it to sensible headphones like the Audio-Technica MSR7B or even more the Meze 99 Classics and you get a terrific system for a very affordable price. This could even become your main setup at the office, like for me.
Thanks to the new ADC volume control, there is no imbalance even at low volumes, this is rare enough to be noticed. This is true in both single-ended and balanced mode, so you do not have to worry.
The sound is even on the whole frequency chart, if you don’t activate the bass-boost you could say it’s almost transparent. Still, you can hear a very slight bump around 5kHz, this puts a little emphasis on voices. In single-ended mode you don’t hear it as much as in balanced mode though.
Bass : tighter than you would expect, it doesn’t slam as hard as the FiiO Q5 but that was easily fixed with a bigger amp connected to the line-out. If you like big-heavy bass, the bass-boost gives you quite enough of it. You lose in definition and this feels like the Cmoy BB : addictive but deceptive on a long run. I extensively listened to Solee with the FiiO K3, on some DACs it can really become painful but not on this one. It’s a good balance of fun and performance.
Treble : the little voice emphasis is pretty interesting with jazz and pop. You can definitely feel the parenthood between the latest FiiO generation : a mellow, soft treble, the velvet signature of AKM chips. Where Sabre DACs amazed me with technicalities, AKM seems to be kinder to the ear. If you love Diana Krall or Gregory Porter, you’ll be fond of the FiiO K3.
Highs : a bit recessed in my opinion, even in balanced mode the Fiio K3 doesn’t reach as far as others. Like the bass, once you plug a good amp to the line-out you can hear what’s missing. Surprisingly it was when I connected the FiiO K3 to my new KEF LSX speakers that I could truly hear what this unit was about. It’s much more potent that I expected, with good extension and quick attack/delay. Violin sound is a good way to fault a unit and this one did a pretty good job on most of my classical playlist.
Let’s cut to the chase, I wanted the FiiO K3 to be good… and it is. It’s so versatile, allowing you to plug almost anything to it on your desktop. It’s powerful enough to drive classic headphones and if you plug another amp to the line-out, it’s just brilliant. It’s a carefully designed product which had to be at least as good as its previous iteration, but the K3 is better in every way.
Honestly, the full late-2018 line-up from FiiO has killer products. They are well made, cheap and cover basically every need. Even more, they all sound good and even great like this little FiiO K3. It’s a bit late now for a christmas present, but in 2019, threat yourself with one of these… You won’t regret it, period.