The FiiO K15 is among the first to use two of the new high-end AKM DAC chips, the AK4479SVQ featuring the upgraded 'Velvet Sound' audio technology. The chips achieve low distortion, a wide dynamic range, and extended signal bandwidth, all at low power consumption. Rich detail is retained in both low and high frequencies for a natural and immersive sound experience.
Within the K15 is a carefully designed discrete headphone amplifier circuit, featuring an OP + transistor current-boosting design. A complementary pair of the classic ON Semiconductor MJE243G/253G delivers high current and low impedance output. This discrete circuit can achieve balanced output power up to 3000mW + 3000mW, allowing the K15 to effortlessly drive both full-sized headphones and in-ear monitors, producing smooth, natural, yet melodious sound.
From DAC decoding, low-pass filtering, and gain control to headphone amplification, the K15's audio circuit is a fully differential design. Such a design ensures wide dynamic range while also effectively reducing crosstalk, minimizing noise, and enhancing the quality of sound.
DC/AC Dual Power Supply
The K15 features a built-in next-generation 30W low-noise, high-efficiency, long-lasting, industrial and instrumentation-grade power supply. The K15 also supports external DC power supplies, allowing it to work with higher-performance linear power supplies for even higher sound quality.
Separate Digital and Analog Section Power Supplies
Such a design helps to effectively avoid crosstalk between the digital and analog sections of the audio circuits. The result is better power isolation and improved anti-interference abilities.
Multi-Stage Analog Power Supply
The analog section features a precisely-segmented multi-stage power supply, including stages for digital-to-analog conversion, LPF, and transistors.
Inside the K15 is the industry-leading ACCUSILICON ultra-low phase noise AS318-L crystal oscillator (45.1584MHz, 49.1520MHz) that effectively reduces phase noise interference in audio signals. This promises precise reproduction of audio signals at various sampling rates.
High-Performance Multi-Core X2000 Processor
This processor is powered by a unique design featuring dual XBurst@2 cores + XBurst@0 micro-core, to deliver exceptional computing performance at ultra-low power consumption. This ensures precise audio signal processing, guaranteeing stable and smooth music playback.
Efficient MCU ESP32-S3
Integrated into this chip is a high-performance Xtensa 32-bit LX7 dual-core processor and an ultra-low-power coprocessor, featuring a clock speed of up to 240MHz. This chip enables precise system control for a highly efficient and fast user experience.
The K15 features FiiO's signature design blending square and round elements, merging retro elegance with cutting-edge technology. Thoughtfully crafted for both functionality and aesthetics, it displays convenient screen controls and multiple knobs for smoother operation. In addition, the grid structure enhances heat dissipation, showcasing the brilliance of its meticulous design.