Setup, Customization, and Performance

Desktop Setup

Given the FiiO K7 is a DAC/headphone amp/preamp all-in-one unit, the number of wires that go in the back is fully dependent on how you plan on using it. I suspect most readers of this review will be using it primarily as a USB DAC for input, although the other inputs can be quite handy with non-desktop sources, such as a CD player, a phono stage, or even a TV. I ended up using the USB DAC functionality paired with my laptop in my home office, which means using the provided USB cable—sadly not Type-C as previously pointed out—in addition to the power cable/external power supply itself. The power connection is long enough courtesy the two cables involved to where I could easily place the K7 on my desk without worrying about being able to reach an available wall socket.


Turning on the FiiO K7 is as simple as rotating the volume wheel past the minimum point. You will hear an audible click and notice the USB input indicator LED turn on along with a color flow effect on the LED ring surrounding the volume wheel itself. I can see some people deliberately adding in an external switch relay on the back but then again I am not sure how practical it is for the more mainstream market the K7 appeals to. Perhaps this is also why we see FiiO go with a brighter LED ring this time than on the K5/K9 Pro ESS units, with a deliberate plastic diffuser ring making this a more RGB lit product than most others in the market.The flow pattern lasts for a couple of seconds when turning the device on or switching input modes, after which it defaults to cyan/yellow/green to indicate the playback type/sampling rate itself as outlined in the user guide. It's overly bright at night and I have already seen people complain about the lack of any option to turn off the lights. Perhaps this is where that circular foam cutout that came over the wheel out of the box can be handy to help block out the light, and FiiO is also looking to gauge user feedback on whether or not to implement a firmware update that turns off the LEDs. I don't mind it too much given it's not often I'll be using this and my desktop/laptop in a dark environment anyway and, if anything else, I'd wager that FiiO is instead spending time trying to see what other lighting effects can be pulled out of the LED ring here in an attempt to appeal further to the gaming/RGB crowd.


Using the FiiO K7 with Windows 10 or 11 doesn't require any additional drivers, with Windows recognizing the device automatically. We see that the default firmware provides PCM playback options up to 32-bit, 384 kHz in addition to DSD256. The USB decoder comes in handy here, and all your favorite players will recognize the device in WASAPI (Windows Audio Session API) mode accordingly. There should be equivalent drivers pre-configured in newer macOS builds too, but I am not familiar enough to speak on this front. Keep in mind that the K7 does a potentially annoying thing wherein it defaults to the USB input at each power cycle even if you are using it with another input, meaning the device does not remember the previous input settings.


If you have a device that doesn't accept UAC 2.0, or even if you simply want to try other options, then the FiiO USB audio device drivers will be of interest to you. You can find the installer on this page and the latest version at the time of testing was v5.30.0. Installation is trivial as seen above, and these drivers now allow you to make the most of the FiiO K7 within the Windows operating system.



What it then does is create a new output device in Windows as well as provide access to the FiiO USB Audio Control Panel. Just be sure to set the format to 24-bit and choose the ASIO (Audio Stream Input/Output) buffer size that suits your latency requirements—that's about it. With that done, go to your media player of choice. I demonstrated above with JRiver again and set the audio player to the same output. At this point, you can implement further tweaks, but those are player dependent. These drivers also provide 24-bit playback support for those who find it useful.

Audio Performance

This is a good segue to summarize the capabilities of the FiiO K7 and its dual AK4493S mobile flagship-class DACs that omit support for everyone's favorite controversial audio topic in the form of MQA on-device rendering. As such, if MQA playback over Tidal is important to you then the FiiO K7 is not the device for you. I personally don't care about MQA and would rather have the 32-bit 384 kHz PCM and DSD256 playback support over USB. Note that this goes down to 24-bit 192 kHz over coax and 24-bit 96 kHz over optical without any DSD support here, and this suggests FiiO is using a less powerful decoder for these inputs. More things to be aware of although not really a concern for the majority of our TPU readerbase if I say so myself. Indeed, having both single-ended 6.35 mm and balanced 4.4 mm headphone outputs in addition to line out and preamp functionality would be more important features. The FiiO K7 packs plenty of power here with a rated 1.22 W per channel at 32 Ω going down to 140 mW at 300 Ω off the 6.35 mm output and these increase to 2000/560 mW at 32/300 Ω, respectively, off the 4.4 mm connection. It's more power than even most flagship headphones need, and I barely found myself even going to high gain mode on the K7 except when trying it with more demanding headphones such as the MOONDROP VENUS we recently saw. Instead, the limitation with the FiiO K7 is the lack of a true low gain mode here—think -6/0/+6 dB for low/medium/high gain modes, for example, rather than the low and high gain modes here that only start at 0 dB and go higher. Thankfully the volume control coupled with the clean, dark background here means you can go quite low in power and not have a case of sensitive IEMs hissing. The photos shown above are typically the other way round when it comes to practicality and I did so deliberately to see whether the K7 could curb its enthusiasm when it comes to power delivery. You'd be more likely to go with the balanced connector for demanding headphones and use IEMs such as the FiiO FH7S off the 6.35 mm output (w/adapter provided) instead.


I spent a few days using only the FiiO K7 with a variety of IEMs and headphones to fully test how it sounds, knowing already that it does have enough juice as mentioned above. The line out features worked very well and I have no complaints on that front. I was also tempted to use it in a pure DAC mode to drive e-stats off the Headamp BHSE but decided it was too impractical to bother. Aside from the occasional delay in changing input/output modes, simply listening to headphones off the FiiO K7 was where I was convinced this merited a full review. This is one of the better AKM DAC implementations I've heard and certainly comes off not having as much glare in the higher frequencies as your typical ESS DAC implementation. There's a slight richness to the sound which could very well be placebo but it easily bested the more expensive xDuoo TA-22 when it comes to pure audio reproduction and fidelity of the sound itself. This is likely where the more transparent topology and the THX amplifiers come in handy, and I was reminded of the sound from the far more expensive FiiO K9 Pro ESS rather than the K5 Pro ESS this is priced far closer to! If anything, I might even be so bold as to suggest the K7 is less smooth compared to the K9 Pro ESS but potentially more dynamic and engaging.