FiiO K17 R2R

All-in-One Streaming DAC and Headphone Amplifier

• Proprietary, segmented 24+5-bit R2R-PRO resistor array
• Supports Qplay/NAS/Roon Ready/AirPlay
• High-quality wooden side panels made from imported white ash and black walnut
• High-precision, lossless 31-band PEQ with support for AUTO-EQ
• Headphone amplifier with discrete Class AB current amplification
• Powerful output of 4000 mW + 4000 mW
• Fully balanced design
• Low-noise, linear 35 W low-frequency power supply
• 3.93-inch touchscreen
• Aluminum alloy infrared remote control included

Harmony of sound and form, a symphony of retro elegance and modern technology

The warm feel of natural wood appeals to the eyes and hands and evokes a timeless aesthetic;

The rich, full-bodied R2R sound signature brings the warmth of analog back to your ears.

K17 R2R—not just to be heard, but to be felt. An experience for all the senses.

FIIO’s proprietary segmented 24+5-bit R2R-PRO resistor array

Based on a segmented architecture, the upper 5 bits are decoded using 31 thermometrically coded resistors, eliminating the error accumulation found in conventional R2R designs and reducing distortion. The result is a sound that embodies everything that is so highly valued in R2R—clear yet smooth, natural, warm, and endlessly listenable.

Square and Circle—the Warmth of Real Wood

Building on the classic square-and-circle design, the side panels have been reinterpreted. Choose the silver chassis with imported ash wood for a clean and understatedly elegant look; opt for the black chassis with imported black walnut for a deeper, more subdued sophistication. The organic grain of the solid wood and the precision of the metal complement each other in perfect contrast—and since no two pieces of wood are alike, every unit is one of a kind. Multiple rotary controls allow for smooth, intuitive operation, while the grille structure ensures efficient heat dissipation. Every detail, no matter how small, has been carefully considered.

*The side panels are crafted from select natural wood imported from North America. Since each wood grain is uniquely shaped by nature, the appearance of the actual product may vary.

Play anything from anywhere: Qplay Casting + NAS Playback

Thanks to Roon Ready, AirPlay, and Qplay certifications, the K17 R2R works seamlessly with the platforms and devices you already use. The newly added NAS server playback integrates your home music library and supports NFS and SMB protocols with one-click access via the FIIO Control app.

From cloud streaming to lossless playback on your local network—whatever you want to listen to, the K17 R2R brings it to your ears.

Eight Operating Modes

Streaming Media Receiver: Enjoy streaming content via Roon Ready, QPlay, or AirPlay.

Local Playback: Supports local storage media and LAN NAS devices where your personal music collection is stored.

Single-Ended Line Input: Receives a single-ended analog signal for amplification by the K17 R2R.

Balanced line input: Receives a balanced analog signal for amplification by the K17 R2R.

USB decoding: The XMOS 16-core XU316 enables support for up to 768 kHz/32-bit, DSD256, and full MQA decoding.

Bluetooth decoding: The Qualcomm QCC5125 supports Bluetooth 5.1 as well as the aptX HD, aptX Adaptive, and LDAC formats.

Optical decoding: Receives digital audio signals via the optical port.

Coaxial decoding: Receives digital audio signals via the coaxial port.

A mixer for desktop hi-fi systems

Lossless tuning, effortless control

Specialized chips for specific applications, exceptionally powerful

The K17 R2R features an M21586Q DSP chip capable of performing 64-bit double-precision floating-point calculations and running at a high clock frequency of 360 MHz. This chip is complemented by a high-performance ES9821Q ADC and a specially tuned femtosecond quartz oscillator with extremely low phase noise. These three components enable the user to utilize the high-precision, lossless 31-band PEQ in all operating modes. The PEQ is designed so that the audio signal retains a high degree of fidelity even after processing. The chip also provides a robust output protection function that ensures headphones and other connected audio devices are fully protected.

High-precision, lossless 31-band PEQ

Thanks to DEL (Dual Engine Limiter) technology combined with proprietary algorithms, the K17 R2R’s PEQ offers functions for dynamic range compression (DRC) and dynamic range expansion (DRE), as well as limiter and compressor adjustments. PCM signals ranging from 44.1 kHz to 96 kHz can be processed in the PEQ without sample rate conversion. This enables fine-tuning of audio parameters, including a gain range of +12 to -24 dB and a Q-value range of 0.4 dB to 128 dB. With the PEQ, users can simulate or correct the frequency response curve. PEQ settings can be easily exported, imported, shared, and saved—so anyone can use the PEQ with ease to correct or simulate different frequency response curves for various headphones.

Supports AUTO EQ

Your ideal sound—just a tap away

Do you find manually adjusting a lossless 31-band PEQ too complex?

AUTO EQ automatically adapts to the target curve of your headphones and instantly unlocks your ideal listening profile with a single click, while the sound remains flawless and lossless. It also features built-in presets for pop, jazz, and classical music, as well as the freedom to adjust and fine-tune band by band—giving you complete personal control over your ideal sound.

Discrete Headphone Amplifier with Class AB Current Amplification

A key component of the K17 R2R is a carefully engineered, fully discrete headphone amplifier circuit. This discrete circuit is based on an OP+ transistor current amplifier design and features the classic MJE243/253 transistor pair from ON Semiconductor. It is capable of delivering high current at low output impedance. The result is an output power of up to 4000 mW + 4000 mW in balanced mode—nearly twice that of the K9 Pro ESS. This allows it to effortlessly drive various types of headphones and IEMs, producing a smooth, pleasant, and natural sound.

Fully Balanced Design

From the DAC through the I/V conversion and low-pass filtering to the headphone amplifier, the entire audio circuit is designed as a fully differential circuit architecture. This ensures both a high dynamic range for the signals and significantly reduced crosstalk. Various parts of the audio circuitry, including the I/V conversion and the LPF stages, use multiple low-noise precision operational amplifiers from Texas Instruments (TI) to ensure dynamic audio output.

Physically Separate Circuit Boards

The various sections of the internal power supply, as well as the digital and analog sections, are all located on physically separate circuit boards to prevent mutual interference. This ensures the accuracy and integrity of signal processing for a cleaner, clearer audio output.

Precise Power Supply Design

35-W low-noise linear power supply, five large 4700-μF electrolytic capacitors

The K17 R2R is powered by a custom-built, high-quality, low-noise transformer that ensures the purity of the supplied power. In addition, five 4700-μF electrolytic capacitors provide ample power reserves to ensure a constant power supply.

Separate Power Supplies for Analog and Digital Circuits

Separate power supplies for the digital and analog circuits effectively prevent crosstalk and interference between them.

Multi-stage analog power supply

The K17 R2R’s analog audio circuit is powered by a multi-stage power supply. Many of the stages have their own power supply control, including those for digital-to-analog conversion and the LPF. Low-noise TPA7A47/7A33 LDO regulators with high power supply rejection ratio (PSRR) also function as secondary voltage regulators to provide continuously stable and clean power.

Precisely reproduced sound—every detail, no matter how small, is audible

3 femtosecond audio quartz oscillators with low phase noise

The K17 R2R uses two industry-leading ACCUSILICON AS318-L femtosecond crystal oscillators with extremely low phase noise (45.1584 MHz, 49.1520 MHz), as well as a femtosecond oscillator with extremely low phase noise custom-designed by FIIO (12 MHz). These significantly reduce the impact of phase noise on audio signals, enabling precise and faithful reproduction of audio signals at various sampling rates—resulting in a purer and more consistent sound.

High-End Components—Everything for Great Sound

4 audio-grade Nichicon capacitors + 4 ELNA SILMIC II capacitors + 6 audio-grade ELNA RA3 capacitors + 4 audio-grade WIMA capacitors

High-quality sound, great soundstage

8 Panasonic film capacitors + 32 chip resistors

Low temperature drift and low noise ensure consistent sound quality at both high and low temperatures.

High-quality Rubycon solid-state capacitors

Extremely low ESR value, high immunity to interference, stable and clean power supply

4 sets of silver-plated, oxygen-free copper interconnect cables

Audio signals are transmitted between the various internal circuit boards with minimal loss thanks to the use of high-quality, silver-plated, oxygen-free copper wires.

Gold-plated NEUTRIK connectors

Tulip-shaped connectors that are resistant to oxidation and wear, enabling precise and reliable connections.

Dual-core design, smooth and stable performance

High-performance X2000 multi-core processor: The processor features a unique design consisting of an XBurst2 main CPU core with two logic CPUs, as well as an XBurst Small Core. This chip delivers outstanding computing power with low power consumption. The X2000 ensures precise audio signal processing and stable, smooth audio playback.

Power-efficient ESP32-S3 SoC: This chip includes a powerful Xtensa 32-bit LX7 dual-core processor capable of operating at up to 240 MHz, as well as an ultra-low-power coprocessor. Thanks to this SoC, the K17 R2R delivers a fast and smooth user experience.

Versatile control options, easy operation

3.93-inch touchscreen control panel

The specially designed 3.93-inch LCD screen lets you quickly adjust various settings and access numerous functions with a single touch.

5 control knobs

With just one press, you can put the device into standby mode. The controls also let you quickly and easily adjust the volume, output level, and other settings.

Included aluminum alloy infrared remote control

With the remote control, you can conveniently switch between operating modes, select EQ settings, and adjust the volume from a comfortable distance.

Smart app connectivity

The K17 R2R supports connection to the FIIO Control app, allowing you to easily customize various functions such as local playback and NAS multimedia services.

Multiple Protection Systems – Enjoy with Peace of Mind

Enjoy your music with complete peace of mind thanks to various protection mechanisms that intelligently detect abnormal conditions and trigger automatic protective measures to prevent damage to the device. These include: temperature protection for the headphone amplifier, temperature protection for the transformer, output overload protection, output DC protection, and input overcurrent protection.

Wired or wireless—always online

The Ethernet port supports speeds of up to Gigabit for fast and stable data transmission. The AP6256 Wi-Fi module supports 2.4-GHz and 5-GHz wireless networks as an alternative, yet equally stable method for transmitting lossless audio data.

Numerous Application Scenarios

Scenario 1: The K17 R2R is connected to a computer via USB, allowing headphones and powered speakers to be connected simultaneously.

Scenario 2. The K17 R2R is connected to a NAS via the FIIO Control app to play music.

Scenario 3. The K17 R2R plays music via Roon Ready and is controlled via the Roon Remote app.

Scenario 4: The K17 R2R is connected to an amplifier and passive speakers and receives music from an iPad via AirPlay.

Scenario 5: The K17 R2R is connected to a digital music player via the front USB port, with headphones or powered speakers connected.

Scenario 6. The K17 R2R is connected to a USB flash drive or portable hard drive and plays music locally through headphones or powered speakers.

Scenario 7. The K17 R2R receives an analog signal from a digital music player, processes the signal with PEQ, and outputs it through headphones or the line output.