The FiiO K15 Features New Dual AKM DAC Chips That Deliver Rich Detail Across the Entire Frequency Range Class-AB transistor current-boosting headphone amp circuit Powerful 3000mW + 3000mW balanced output Dual AKM AK4497S DAC chips Two ultra-low phase noise femtosecond crystal oscillators 3.93-Inch touchscreen Dual High-End AKM DAC 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. Discrete Architecture 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. Fully Balanced Audio Circuit 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. Precisely Designed Power Supply DC/AC Dual Power SupplyThe 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 SuppliesSuch 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 SupplyThe analog section features a precisely-segmented multi-stage power supply, including stages for digital-to-analog conversion, LPF, and transistors. Precisely Restored Signals 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. Dual Master Cores High-Performance Multi-Core X2000 ProcessorThis 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-S3Integrated 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. A Harmonious Fusion 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.
