*Pictures are for reference only. The real product may vary.

Fully balanced audio circuit

From DAC decoding, low-pass filtering, gain control, and 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 audio output.

Leading the new ‘core’ generation Dual high-end AKM DAC AK4497S

The K15 is among the first to use two of the new high-end AKM DAC chips, 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.

VELVET SOUND is a brand that embodies the sound philosophy of AKM’s new-generation audio products. It aims to achieve 'true-to-life sound reproduction' by fully utilizing audio technology, delivering an authentic and immersive acoustic experience with no compromises.

*Trademarks is the property of AKM

Discrete architecture

Class-AB transistor current-boosting headphone amplifier circuit

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.

Eight operating modes

*The max current output of the USB-A port is 500mA, suitable for USB flash drives. If you need to connect a portable hard drive, please connect a separate power supply for it.

Physically separated boards

The internal power supply, digital, and analog sections each lie on separate physical boards, physically preventing crosstalk. This effectively ensures the precision and integrity of processed audio signals, for pure and quality sound.

Precisely designed power supply

DC/AC dual power supply

The K15 features a built-in next-generation 30W (12V-2.5A) 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.

*12V-2.5A external DC power supplies are supported

85~305VAC Ultra-wide input voltage range -40°C~85°C Operating temperature

500000 hours Ultra-high reliability

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 by ensuring 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. The power supply utilizes up to 14 low-dropout linear regulators to ensure a continuous supply of stable and pure power.

Precisely restored signals Every last detail heard

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 ensures precise reproduction of audio signals at various sampling rates, for purer and more stable sound.

2 Accusilicon low phase noise femtosecond audio crystal oscillators

High-end parts,All for sound

2 Nichicon 3300uF audio capacitors + 4 ELNA MILIC II capacitors + 8 ELNA RA3 audio capacitors

Higher quality sound with a better soundstage.

8 ruby film capacitors + 32 wafer resistors

Low temperature drift, low noise, mean stable sound quality in both hot and cold environments.

sets of silver-plated oxygen-free copper interconnect wires

The various boards are connected with silver-plated oxygen-free copper wires to ensure high-fidelity signal transmission with minimal loss.

High-quality Beryl capacitors

Ultra-low ESR, strong anti-interference abilities, for a stable and pure power supply.

Dual master cores Stable and smooth experience

High-performance multi-core processor X2000: 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.

A harmonious fusion of square

and round Brilliance in design

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 features convenient screen controls and multiple knobs for smoother operation. In addition, the grid structure enhances heat dissipation - all showcasing the brilliance of its meticulous design.

Touch control /Knob control /Remote control /FiiO Control App connection

10-band high-precision PEQ Unlimited fun

All digital inputs of the K15 support PEQ adjustment*. Precisely fine-tune the sound to your liking by simulating and modifying the frequency response curve of headphones, thanks to FIIO’s proprietary adjustment algorithm and interface.

* Digital inputs include USB, coaxial, optical, Bluetooth, streaming media and local playback. *Web PEQ location: Top bar of FIIO website – Support – Web-based PEQ settings

Multiple protection systems

Listen worry-free

Not only has the device gone through rigorous testing in FIIO labs, it also contains various protection systems that can intelligently detect abnormal conditions and take actions accordingly to protect you, avoiding damage to the machine.

The Gigabit Ethernet port supports fast and stable wired data transmissions, while the AP6256 Wi-Fi module supports 2.4G and 5G band wireless networks as another way to stably transmit lossless audio.

Wired or wireless

Always a stable connection

Independent Ethernet port, supports Gigabit wired network

Supports 2.4G and 5G band wireless networks

Wide variety of usage scenarios

Buttons and ports labeled

*Adjusting the equalizer via the webpage requires connecting to the RS232 port on the rear panel.

*The maximum output current of the USB-A port is 500mA, which is suitable for connecting to a USB flash disk. If you need to connect to a mobile hard disk drive, please use an extra power supply to power it!

Packing list

①----------------------------------------------K15*1

②--------------------------------AC power cord*1

③-------------------------------Remote control*1

④----------------------  XLR4 decorative plug*1

⑤-------------------------------------------    Fuse*1

⑥--------------------------------USB data cable*2

⑦-----------------  Headphone plug adapter*1

⑧-------------------------------- Warranty card*1

⑨-----------------------------Quick start guide*1