FiiO K7 Review

FiiO K7 Review

14 March 2023 0 By Petros Laskis

FiiO K7 Review


Pros: + Balanced and natural sound signature
+ Musical and engaging
+ Crystal clear and transparent
+ Minimum digital glare
+ Really balanced and powerful headphone amplifier
+ Single ended headphone output is not gimped
+ Analogue and digital inputs
+ Can be used as a DAC, preamplifier, headphone amplifier and all-in-one unit
+ Compact sized
+ Excellent build quality
+ Amazing value for money

Cons: – Not that dynamic and impactful as some of the competition with discrete output stages
– Makes the K5 PRO ESS pretty obsolete
– Not compatible with the FiiO control application
– You can’t dim or disable the RGB light

The review sample was kindly provided free of charge in exchange for an honest review.
I didn’t receive monetary or any other kind of compensation and I don’t use affiliate links.
The price of the FiiO K7 is $199.99 and you can buy it from here.

FiiO K7

As always with FiiO we skip the lengthy introductions because they are so well known that they don’t need one.

The FiiO K7 is the balanced version of the much acclaimed K5 PRO ESS which is one of the best selling FiiO desktop DAC/amps.
For the K7, FiiO have ditched the ESS chip for two pieces of the new AK4493SEQ DAC chip from AKM which is the newest version of the AK4493.
The FiiO K7 has a six-stage audio circuit with truly balanced analogue and digital sections.
Using two pieces of the same THX AAA 788+ amplifiers as the K9 Pro, the FiiO K7 is capable of outputting 560mW into a 300 Ohm load at 1% distortion and 2000mW into 32 Ohm load at 1% distortion from the balanced output.
The XMOS XUF208 input controller uses dual clock management to handle various audio formats.
The K7 can decode 32-bit 768kHz PCM and DSD512 but there is no MQA support.


The K7 features a power design consisting of multiple independent stages, with the voltage of each stage regulated by low-noise LDOs. Feeding this power design is an external 12V switching power supply. All in all, the K7’s power design supplies plentiful, clean power for an extraordinary listening experience.
Overheating, overload, and DC protection systems ensure that the K7 always operates at its best, so you can always enjoy a worry-free listening experience.
Thanks to its ADC curve reconstruction, the volume potentiometer features 112 smooth steps of adjustable volume free of channel imbalances and noise.


Appearance and build quality

The K7 is just slightly larger than the K5 and it features an all-aluminum alloy construction, carefully finished with CNC and other processes.
It has an excellent build quality and a smooth finish with an elegant black color that is perfectly complemented by the gold accents of the THX and Hi-Res Audio badges.
The circular RGB indicator light is capable of displaying single colors as well as mixed colors, with a unique light flow effect during power on/off or input switching.
Blue for ≤48kHz, yellow for >48kHz and green for DSD.
The K7 will not communicate with the FiiO control application so there is no way to disable or dim the RGB light.


User interface

This is a pretty simple to use DAC/amp with three digital inputs (USB, coaxial and optical), a line level input, a line level output and two headphone outputs.
Except for the volume control knob, that also acts as the on/off switch, there is a button for selecting between the various inputs and two toggle switches, one for setting the gain to high or low and another for selecting the desired output (headphone, line out or pre out).
At the right side of the front face there are located the two headphone outputs, one balanced 4.4mm and another single ended 6.35mm.



The K7 comes bundled with an external power adapter, a USB cable and a 6.35mm to 3.5mm adapter.

Associated gear and power output

The K7 can do 1.2W/32Ω from its single ended output, exactly the same as the K5 PRO ESS, while the balanced output is almost doubling to a whole 2W/32Ω.
So it can run pretty much anything except for some exotic headphones and at the same time it is very silent with excellent channel balance.
I have used various earphones to test the performance, like the FiiO FD7, the Penon Vortex and the Meze ADVAR.
A mid gain setting would be nice to have for better headphone matching but I am really nitpicking here.
I did most of my listening tests with the Focal Clear Mg, the HiFiMan Ananda Stealth and the Meze 109 Pro, all of them with pure silver cables made by Lavricables.
As an example of the power output, with the Focal Clear Mg I never needed more than ¾ of the volume range at the low gain setting to get very loud and with excellent driver control while listening to classical music.


Listening impressions

FiiO has a great expertise with the AKM DAC chips and you don’t have to listen a lot to the K7 to understand what is really happening.
A perfectly balanced and neutral tuning with a touch of warmness and a more natural timbre than the K5 PRO, make the K7 one of the most musical and engaging sounding FiiO products.
This is the old beloved FiiO house sound with the AKM flavor that I bet that many of you have been missing during the recent switch to the ESS chips.
A DAC that is perfectly capable of a clean and transparent sound with a mirror-like source fidelity but without sounding clinical, artificial or metallic.
The timbre is very natural and realistic, almost analogue-like and quite organic with plenty of harmonic variety and a colorful tonal palette.
The K7 is highly successful in connecting the listener to his favorite music while it offers very good technicalities for the category.


The bass is extended, fast, tight and controlled with excellent definition and clarity while it sounds quite full bodied and weighty, definitely more visceral than the K5 PRO ESS.
It is dynamic and impactful, certainly not that powerful and authoritative as some other DAC/amps with discrete output stages, like the Aune X1S GT or the Yulong Aurora but still very contrasted and definitely satisfying with bass intense music.
The mid-range is open sounding, lucid and sweet with a high quality texture and fine articulation.
The K7 offers plenty of resolution and refinement for the category with a high spirited and energetic treble which is kept smooth and controlled with a minimum digital glare and without harshness despite the excellent clarity and its luminous nature.
The K7 is very versatile and a great match with every headphone and all types of music, from modern electronic stuff to classical.
I have listened to dozens of recordings and I really remained impressed with the consistency of performance, from favorite rock tunes together with the Meze 109 PRO to the highly demanding Bruckner’s symphony No.9 with the Focal Clear Mg.


The K7 is surprisingly open sounding with an expansive and quite grand presentation with excellent ambient information and a rather sharp imaging especially from the balanced output.

Single ended vs balanced

The single ended output is excellent sounding and very competitive, you shouldn’t be worried at all if you plan to buy the K7 for single ended only use.
But you are still greatly encouraged to upgrade to the balanced, when possible, because it is technically superior, more expansive and articulate with an effortless power delivery that results in a more dynamic and controlled sound with extra headroom.

As a headphone amplifier

Using the line level input and taking the internal DAC out of the equation, the K7 is a very competitive analogue headphone amplifier and preamplifier with great transparency and a sound signature that shares a lot in common with all the characteristics as described above.
A nice option that allows the owner to use an external DAC or a vinyl set-up.

The icing on the cake

I know that spending another $150 to add an LPS to a $200 DAC/amp is a little hard to swallow but trust me that it is worthwhile.
The addition of the FiiO PL50 raises the performance even higher as it makes the most out of the K7 by adding a blacker background that offers deeper detail retrieval.
Additionally you will hear more impactful and contrasted dynamics, fuller and weightier sound with an even more realistic and natural timbre.
No, you don’t need the PL50 to really enjoy your K7 but if you manage to get one at some point in the future then you are going to have a system with a performance level that is quite close to much more expensive products like the FiiO K9 PRO.


Compared to the K5 PRO ESS ($209)

The K7 is fuller sounding than the K5 PRO ESS, especially in the bass department but not exclusively so because the whole frequency range is conceived as more intense and weightier.
The timbre is also slightly more realistic in the K7, the sound is a touch more musical and less artificial, it is also more resolving and refined than the K5 PRO ESS with a larger and grander soundstage.
The differences are audible from the single ended output while the balanced raises the bar even higher.
The initial launch price of the K5 PRO ESS was $219 but after the release of the K7 the street price was lowered to $149.
So the K7 is about $50 more expensive but they are not that much when considering that they buy you a slightly better sounding and more versatile product.
In my opinion, the release of the K7 has made the K5 PRO ESS pretty redundant and obsolete, the only reason for buying it is if your budget is really strictly limited.


In the end

The release of the K7 marks the return of FiiO back to their roots where everything has started.
The AKM DAC chips, in my opinion, better suit the FiiO house sound and the K7 is the living proof of it.
A bullseye for the company, the K7 is one of the most competitively priced DAC/amps in the market right now and it combines a very musical sound signature with great technicalities, great versatility and excellent power delivery.
FiiO is also preparing a Bluetooth version with a minor price increase.
I am pretty sure that the K7 is going to surpass the K5 PRO in sales and become the most successful and best selling product of FiiO ever.
My only wish now, is that they are back to the drawing board already designing the successor to the K9 PRO with AKM DAC chips.

Test playlist

Copyright – Petros Laskis 2023.