FiiO K9 AKM Review

FiiO K9 AKM Review

FiiO K9 AKM Review – The Lates K9 Version With Flagship AKM DACs

The new FiiO K9 AKM features AKM’s latest flagship DAC combo, the AK4191EQ + AK4499EX. With a new design that separates the digital and analog sections, this DAC-AMP-Bluetooth all-in-one combo also includes the innovative “DWA ROUTING technology” to enhance the signal-noise ratio and minimize noise from different amplitudes.

FiiO K9 AKM Review

FiiO continuously improves its products to enhance user experience. When selling the K9 ESS version, FiiO carefully listened to feedback from sales agents and users worldwide. After internal discussions, FiiO decided to develop the K9 AKM version to achieve the unique sound of the AKM DAC chip.

FiiO K9 AKM Review
The side Type-C input is really handy.

The K9 AKM version maintains the rich inputs and outputs of the ESS version, such as coaxial/optical/USB-B/4.4mm/RCA inputs and 6.35mm/4.4mm/XLR-4/RCA/XLR outputs. Additionally, it includes a new Type-C input on the right side of the device, allowing easy connection to cell phones, players, and other devices via the Type-C connector.

FiiO K9 AKM Review

The K9 AKM utilizes the THX AAA 788+ amplifier, just like the high-end K9 Pro. This amplifier ensures an impressive power output of 1% undistorted power up to 780mW at 300Ω and up to 2000mW at 32Ω. It effortlessly caters to both low-impedance and high-impedance headphones.

Every aspect, from DAC decoding to volume adjustment and headphone amplifier driver, undergoes full differential signal processing. This advanced technique effectively minimizes crosstalk.

FiiO K9 AKM Review 28

By separating the power supply and signals into different partitions, and arranging the analog signal loops separately, the integrity of signal processing is guaranteed.

FiiO K9 AKM Review

The advanced station amplifier’s six-level audio architecture allows you to enjoy exquisite singing sounds that are full and pure. It includes I/V conversion, LPF filtering, electronic volume adjustment, voltage follow-up, pre-amplification, and post-driver. To ensure a steady power supply for the analog part, the linear transformer is paired with four 4700uF capacitors that have large capacity and long lifespan.

FiiO K9 AKM Review

Digital circuits and analog circuits are powered separately to prevent any interference between them. A reliable and consistent power supply is crucial for producing high-quality sound. However, the power supply design of K9 AKM goes even further. It incorporates multi-stage voltage stabilization and filtering in the audio circuit. To ensure optimal performance, it implements a hierarchical power supply that aligns with the analog signal processing stages. Each stage is equipped with ultra-low noise LDO for precise voltage stabilization.

FiiO K9 AKM Review

The K9 AKM is equipped with three smart protection circuits that are concealed within its core. These circuits, namely over-temperature, overload, and DC protection, constantly monitor the high-energy performance of the device. They ensure that you won’t experience overheating while using it, keeping you cool and comfortable. Additionally, the K9 AKM features dual-mode clock management technology, which guarantees accurate and stable performance.

This technology excels in decoding high-standard audio and reproduces the sound of each track with utmost fidelity. Whether you’re listening to various music genres, the K9 AKM will make you feel like you’re right there in the moment. Moreover, it supports 768K/32Bit PCM decoding and DSD512.

FiiO K9 AKM Review

FiiO K9 AKM uses a QCC5124 Bluetooth chip and supports high-definition Bluetooth formats such as LDAC/aptX HD/aptX Adaptive.

FiiO K9 AKM supports UAC1.0/UAC2.0. Devices that cannot install drivers can implement plug-and-play. Devices that can install drivers have better compatibility. You can also turn on or off UAC1.0 mode through the FiiO Control APP. In UAC1.0 mode, devices such as PS5 and Switch can be plug-and-play.

The FiiO K9 AKM has three output modes: LO/PRE/PO.

  • LO: Only the RCA+XLR analog interface on the rear panel has output, which is designed for maximum amplitude output and cannot be adjusted by the volume knob.
  • PRE: Only the RCA+XLR analog interface on the rear panel has output, and the output amplitude is adjustable by the volume knob.
  • PO: Only the headphone interface on the front panel has an output and is controlled by the volume knob.

FiiO K9 AKM Review

It also has three levels of hardware gain: High/medium/low.

  • L position: Switch to low gain and low voltage power supply to better match sensitive IEMs.
  • M position: Switch to middle gain and middle voltage power supply to better match with a variety of earphones.
  • H position: Switch to high-gain high-voltage power supply to better drive power-hungry headphones.

Continuing the K9 series design, the AKM version is also made of all-aluminum alloy. The body adopts an integrated stretching + CNC process, which combines precision and strength. Paired with the standard vertical base, whether placed horizontally or vertically, it is a beautiful sight for the desktop audio system.

The big volume knob at the front-center has been reconstructed through the ADC curve and designed with 120 levels of volume, which not only avoids bias and noise in the left and right channels but also allows you to have a precise and smooth experience when adjusting the volume.FiiO K9 AKM Review
The RGB indicators hidden around the knob use different colors to indicate different sampling rates or Bluetooth encoding formats. The colorful lighting effects also add a touch of RGB color to your desktop.

FiiO Control App

FiiO K9 AKM connects to the mobile phone via Bluetooth, and everything becomes fun with the FiiO Control APP. For example, six filters, status indicators, EQ, channel balance, and other customizable functions are all based on your preferences. PEQ function only takes effect for Bluetooth decoding.

What’s In The Box


Full Specs

Price: $529.99

FiiO K9 AKM Review

I would like to thank FiiO for providing me with the review sample of the K9 AKM.


K9 AKM sounds natural, clean, and precise. They are tonally balanced and have a colorless spectrum signature. The K9 AKM’s natural timbre & tonality are the best at this price range. This is a transparent and detail-rich DAC. This is true for clean edges & transient but also for rich inner tone texture.

K9 AKM’s low end is fluid, rich, and textured. The bass is dynamic and impactful. There’s excellent resolution in the mid-bass. It’s not too thick or too thin. The brass family is presented with warmth and accuracy. The transition from the bass to the midrange is smooth, and it maintains a consistent tone across the spectrum. Sub-bass extension isn’t anything to brag about, but it’s noticeable and adds to the overall dynamic.

FiiO K9 AKM Review

K9 AKM’s midrange is where it shines. It strikes a nice balance between linearity and clarity. Vocals come out with definition and detail, and detail retrieval is amazing. Mid-tone instruments like guitars come out naturally with great detail rendition.

The upper midrange is clear and energetic, and the control is pretty good too, with elements such as cymbals/hi-hats in the mix but not too much. Resolution and clarity are excellent, especially for a portable AKM all-in-one.

The K9 AKM has great control over the treble. The highs are well-extended, open, and airy. There is nothing to criticize in the tonality of K9 AKMs. It is a skillful blend of gentle warmth & transparency that gives a very natural and pleasant sound signature. The treble is spacious and well-controlled.

Highs are resolving and clean, but never too hot. Transients are quick and fast, and the fine treble adds to the overall clarity.

FiiO K9 AKM Review

The K9 AKM offers excellent sound quality, with no harshness even at the highest octaves. It maintains good detail and accurately reproduces harmonics. The balance across the entire sound spectrum is very good, matching the depth of the lowest and highest notes. It stays true to the original recording without any loss of sound quality.

Additionally, the K9 AKM is a technically impressive desktop DAC-AMP. The soundstage is wide, although the depth may vary depending on the headphones used, indicating the importance of finding the right synergy. However, when used with compatible IEMs, the depth is satisfactory.

The sound signature is clear and airy, with an impressive separation of instruments, resulting in precise imaging and positioning. The K9 AKM is a remarkable DAC and AMP combo in terms of technical performance.

FiiO K9 AKM Review


In conclusion, the FiiO K9 AKM is a remarkable desktop DAC-AMP that should be taken into account by any music enthusiast seeking top-notch audio quality. With its sleek design, outstanding construction, advanced DAC chip from AKM, and features such as PEQ, it offers great value for the asking price in my opinion.