Overview

The FiiO K9 AKM is a desktop DAC and headphone amplifier manufactured by FiiO of China. This product replaces the ESS DAC chip used in the original K9 with AKM’s flagship DAC chip combo AK4191+AK4499EX. It features a headphone amplifier section powered by THX AAA 788+ dual modules, delivering 2000mW at a 32Ω load and 780mW at a 300Ω load in balanced connection. The unit supports 768kHz/32bit PCM and DSD512, includes Bluetooth connectivity, and is positioned as a multifunctional all-in-one product.

Scientific Validity

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The measurement performance nearly achieves transparent levels. Its THD+N of 0.00027% is significantly better than the transparent level standard of 0.01% or less, and its S/N ratio of 124dB exceeds the transparent level standard of 105dB or more. The frequency response is flat from 20Hz-50kHz, extending beyond the audible range, and the output impedance of less than 1Ω is excellent. The noise floor is extremely low at under 8μV for the unbalanced output and under 9.3μV for the balanced output, with crosstalk also being well-suppressed. These measured values are sufficient to contribute to an audibly transparent sound quality, and a scientifically meaningful improvement in sound quality can be expected.

Technology Level

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The adoption of AKM’s flagship DAC chips, the AK4499EX and AK4191 combo, achieves a technical implementation that is above the industry standard. Technologies that contribute to improved measurement performance have been incorporated, including DWA ROUTING technology for S/N ratio improvement and dual clock management via an XMOS XUF208 decoder. The amplifier section, using THX AAA 788+ dual modules, also represents a proven low-distortion design. However, these are combinations of existing technologies that are widely adopted by other companies, with FiiO’s own innovative technology being limited. While the technology level exceeds the industry average, it does not reach the highest standards.

Cost-Performance

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For its price of 792 USD, there are several less expensive alternatives with equivalent or superior functionality and measurement performance. The most price-efficient comparison target is the Topping DX3 Pro+ (approx. 200 USD). The DX3 Pro+ features an ES9038Q2M DAC chip, a THD+N of 0.00015%, an SNR of 120dB, and an output of 1800mW at a 32Ω load, offering comparable basic performance and features to the K9 AKM at a much lower price. The cost-performance calculation is 200 USD ÷ 792 USD = 0.252, which indicates that the K9 AKM’s price efficiency is low.

Reliability & Support

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FiiO’s one-year warranty period is the industry average. The quality of customer support varies by region, with relatively good evaluations in Europe, while delays in response and reports of inappropriate repairs have been noted in Asia. While specific data on product failure rates is not publicly available, sporadic reports of initial defects can be found in communities like Head-Fi. In the Japanese market, sales and support systems are established through authorized distributors, but there is a risk of extended repair times as items may need to be sent to the headquarters in China. Overall, it remains at an industry-average level.

Rationality of Design Philosophy

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The scientific approach aimed at achieving transparent-level measurement performance is rational. The adoption of AKM’s flagship DAC chips and the use of a THX-certified amplifier module seek performance improvements through proven technologies. Support for 768kHz/32bit PCM and DSD512 are specifications that correspond to current high-resolution audio sources. However, questions remain regarding the necessity of a dedicated desktop DAC and amplifier unit. Equivalent functionality and performance can be achieved with less expensive compact products or a PC + external DAC combination, making the need for a large enclosure and a dedicated power supply limited. While improvements in convenience such as Bluetooth support are commendable, the differentiating elements are insufficient to justify the price.

Advice

While the FiiO K9 AKM is a product with excellent measurement performance, it is not recommended from a price efficiency perspective. For those seeking equivalent sound quality and functionality, alternatives such as the Topping DX3 Pro+ are available for about a quarter of the price. The DX3 Pro+ achieves equivalent or superior basic performance with 1800mW output, a THD+N of 0.00015%, and an SNR of 120dB for approximately 200 USD, leaving no rational reason to choose the K9 AKM. With a budget of 792 USD, it is strongly recommended to select a more price-efficient DAC and amplifier and allocate the remaining funds to upgrading headphones or speakers. Unless there is a special attachment to the tonal characteristics of AKM chips, product selection should be based on objective performance and price comparisons.

(2025.8.2)