The FiiO K15 is a full-featured desktop DAC and headphone amplifier that sits above the K11 R2R in FiiO's desktop range, combining a pair of AKM AK4497S DAC chips with a discrete Class-AB transistor headphone amplifier in a single chassis. It is the first consumer audio product to use the flagship AKM AK4497S in a dual configuration, and is designed for desktop listening at home or in a studio environment, offering a fully balanced audio circuit, network streaming capability, and a comprehensive set of digital and analogue inputs and outputs.
Dual AKM AK4497S DAC Section
The K15 uses two AKM AK4497S chips, which feature AKM's VELVET SOUND audio technology. Configured in a fully differential, dual-monaural arrangement, these chips deliver low distortion, a wide dynamic range, and extended signal bandwidth while retaining fine detail across the frequency range. A fully differential signal path from DAC decoding through low-pass filtering and gain control to headphone amplification ensures that crosstalk is minimised at every stage. Full MQA hardware decoding is supported.
Discrete Class-AB Headphone Amplifier
Headphone amplification is handled by a discrete OP-amp plus transistor current-boosting circuit using a complementary pair of ON Semiconductor MJE243G/MJE253G transistors. This design delivers high output current with low output impedance, providing balanced output power of up to 3,000 mW per channel, making the K15 capable of driving demanding full-sized headphones as readily as sensitive in-ear monitors. The sound character is smooth and natural, with the warmth typical of a well-designed transistor output stage.
Precision Clocking and Power Supply
Two ACCUSILICON AS318-L ultra-low phase noise crystal oscillators (45.1584 MHz and 49.1520 MHz) provide precise clocking across all supported sample rates, minimising jitter and ensuring stable signal reproduction. The internal circuits are arranged on physically separate boards for power supply, digital, and analogue sections, preventing inter-section crosstalk. The analogue stage uses 14 low-dropout linear regulators across multiple supply stages, and the built-in 30 W industrial-grade switched-mode power supply can be substituted with an external 12 V DC linear supply for further improvement in perceived noise floor.
Streaming, Connectivity, and Control
The K15 includes a Gigabit Ethernet port and a dual-band Wi-Fi module (2.4 GHz and 5 GHz) for lossless network streaming, as well as bidirectional Bluetooth. Digital inputs cover USB, coaxial S/PDIF, optical TosLink, and network sources; analogue inputs include RCA and XLR. Line outputs are available as RCA and balanced XLR. Headphone outputs include a 6.35 mm single-ended socket, a 4.4 mm balanced (Pentaconn) socket, and a four-pin XLR balanced socket. Eight distinct operating modes allow flexible use as a DAC only, headphone amplifier only, pre-amplifier, or various combined configurations. A 10-band high-precision parametric equaliser applies to all digital inputs and can be adjusted via the FiiO Control app, the 3.93-inch touch screen, physical knobs, or an included infrared remote.
Also Available As: Silver
