FiiO K17 R2R All-in-One Streaming DAC & Headphone Amplifier

Harmony Between Sound and Form. A Symphony of Retro Elegance and Modern Technology

The warm touch of natural wood, pleasing to both the eyes and hands, evokes a timeless aesthetic. The rich and full-bodied R2R sound signature brings the warmth of analog back to your ears. The K17 R2R is not simply heard — it is experienced. A resonance that engages all the senses.

FiiO Proprietary 24+5-bit Segmented R2R PRO Resistor Array

Based on a segmented architecture, the upper 5 bits are decoded using 31 thermometer-coded resistors, solving the error accumulation issue found in traditional R2R designs and reducing distortion. The result is a sound that captures everything people love about R2R: clear yet smooth, natural, warm, and endlessly enjoyable for long listening sessions.

Square and Circle. The Warmth of Real Wood

Building upon the classic square-and-circle design, the side panels have been completely redesigned. Choose the silver chassis with imported ash wood for a refined, clean, and quietly elegant appearance, or the black chassis with imported black walnut for a deeper and more reserved sophistication.

The natural grain of solid wood and the precision of metal craftsmanship create a perfect contrast. Furthermore, because every piece of wood is unique, each unit has its own individual character. Multiple knobs provide smooth and intuitive control, while the grille structure ensures efficient heat dissipation.

The side panels are crafted from carefully selected natural wood imported from North America. Since every grain pattern is uniquely created by nature, the appearance of the actual product may vary.

Play Anything, Anywhere – QPlay Casting + NAS Playback

With 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 feature brings your home music library directly into the system, supporting NFS and SMB protocols with instant access through the FIIO Control app.

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

Eight Operating Modes

• Streaming media receiver — Roon Ready, QPlay, or AirPlay

• Local playback — internal storage and LAN NAS

• Single-ended line input — amplification of an analog SE signal

• Balanced line input — amplification of a balanced analog signal

• USB decoding — 16-core XMOS XU316, up to 768 kHz/32-bit, DSD256, full MQA decoding

• Bluetooth decoding — Qualcomm QCC5125, Bluetooth 5.1, aptX HD / aptX Adaptive / LDAC

• Optical decoding

• Coaxial decoding

A Mixing Console for Desktop Hi-Fi. Lossless Tuning, Effortless Control

Specialized Chips for Specialized Applications

The K17 R2R features an M21586Q DSP capable of performing double-precision 64-bit floating-point calculations at a 360 MHz clock speed, combined with a high-performance ES9821Q ADC and a customized ultra-low phase-noise femtosecond oscillator.

Together, these components allow the use of a high-precision 31-band lossless PEQ in every operating mode, maintaining high-fidelity signal quality even after processing while providing advanced output protection for headphones and connected devices.

31-Band High-Precision Lossless PEQ

DEL (Dual Engine Limiter) technology and proprietary algorithms provide the PEQ with dynamic range compression (DRC), dynamic range expansion (DRE), limiter, and compressor functions.

PCM signals from 44.1 kHz to 96 kHz are processed without sample rate conversion. Precise adjustments are possible with a gain range from +12 to -24 dB and a Q range from 0.4 to 128, allowing simulation or correction of any frequency response curve.

Settings can be easily exported, imported, shared, and saved.

Supports AUTO EQ – Your Ideal Sound with One Tap

Do you find manually adjusting 31 bands too complicated? AUTO EQ automatically matches your headphones’ target curve, instantly unlocking your ideal profile with a single click while preserving pure, lossless audio quality.

Built-in presets for Pop, Jazz, and Classical are included, along with complete freedom to fine-tune every band individually.

Discrete Class AB Current Amplification Headphone Amplifier

A fully discrete amplifier circuit carefully designed with an OP + transistor current amplification topology, equipped with the classic ON Semiconductor MJE243/253 transistor pair.

Capable of delivering high current with low output impedance, it provides up to 4000 mW + 4000 mW balanced output, nearly twice that of the K9 Pro ESS, effortlessly driving everything from sensitive IEMs to demanding full-size headphones with a smooth, pleasant, and natural sound.

Fully Balanced Design

From the DAC to I/V conversion, low-pass filtering, and headphone amplification, the entire audio circuit uses a fully differential architecture, ensuring high dynamic range and significantly reduced crosstalk.

Multiple low-noise, high-precision Texas Instruments operational amplifiers are used throughout the I/V and LPF stages.

Physically Separated Circuit Boards

The power supply, digital, and analog sections are placed on physically separated circuit boards, preventing interference between them for purer and cleaner audio output.

Precision Power Supply Design

35 W Low-Noise Linear Power Supply + Five Large 4700 μF Capacitors

A custom high-quality low-noise transformer ensures the purity of the supplied power, while five 4700 μF electrolytic capacitors provide ample energy reserves for a stable power supply.

Separate Power Supplies for Analog and Digital Circuits

Effectively reduces interference and crosstalk between the two sections.

Multi-Stage Analog Power Supply

The analog audio circuit uses a multi-stage power supply, with multiple stages, including DAC conversion and LPF, equipped with dedicated power management circuits.

Low-noise, high-PSRR TPA7A47/7A33 LDO regulators act as secondary voltage regulators, providing continuously stable and clean power.

Precisely Restored Audio – Three Ultra-Low Phase Noise Femtosecond Oscillators

Two industry-leading ACCUSILICON AS318-L ultra-low phase-noise femtosecond crystal oscillators (45.1584 MHz and 49.1520 MHz) work together with a customized FiiO 12 MHz femtosecond oscillator.

This configuration significantly reduces the impact of phase noise, allowing audio signals at every sampling rate to be faithfully restored, delivering purer and more consistent sound.

High-End Components, All for Exceptional Sound

• 4 Nichicon capacitors + 4 ELNA SILMIC II + 6 ELNA RA3 + 4 WIMA audio-specific capacitors — high-quality sound and a wide soundstage

• 8 Panasonic film capacitors + 32 chip resistors — low temperature drift and low noise for consistent sound performance in all conditions

• High-quality Rubycon solid capacitors — ultra-low ESR, excellent interference resistance, stable and pure power delivery

• 4 sets of silver-plated OFC copper cables — minimal-loss signal transmission between internal boards

• Gold-plated NEUTRIK connectors — oxidation resistant, wear resistant, precise, and reliable

Dual-Core Design, Smooth and Stable Experience

A high-performance X2000 multi-core processor (main XBurst2 CPU with two additional logic CPUs and an XBurst small core) provides powerful computing capability with low power consumption, ensuring precise signal processing and stable playback.

A low-power ESP32-S3 SoC, featuring a dual-core 32-bit Xtensa LX7 processor running up to 240 MHz and an ultra-low-power coprocessor, keeps the user experience fast and smooth.

Multiple Control Methods, Easy to Use

• 3.93-inch touch controls — quick adjustment of settings and access to functions

• 5 control knobs — one press for standby; quick control of volume, gain, and settings

• Included aluminum alloy infrared remote control — switch modes, select EQ settings, and adjust volume remotely

• Intelligent app connection — FIIO Control app for local playback, NAS services, and more

Multiple Protection Systems for Worry-Free Listening

Intelligent detection and automatic protection systems monitor headphone amplifier temperature, transformer temperature, output overload, output DC, and input overcurrent.

Always Connected, Wired or Wireless

The Gigabit Ethernet port provides fast and stable transmission, while the AP6256 Wi-Fi module supports 2.4 GHz and 5 GHz networks, offering an equally reliable path for lossless audio.

Specifications | Details

Basic

Color | Black / Silver
Dimensions | Approx. 245 × 223 × 69 mm
Weight | Approx. 2900 g

Hardware

Master control chip | X2000
DAC | FiiO proprietary 24+5-bit segmented R2R PRO
DSP | M21586Q (64-bit floating point, 360 MHz)
ADC | ES9821Q
USB chip | XMOS XU316 (16-core)
Bluetooth chip | Qualcomm QCC5125
Oscillators | 2× ACCUSILICON AS318-L (45.1584 / 49.1520 MHz) + FiiO custom 12 MHz
Display | 3.93-inch LCD touchscreen
Wi-Fi / LAN | AP6256 (2.4G/5G) / Gigabit Ethernet

Bluetooth

Reception | Bluetooth 5.1 — SBC / aptX / aptX LL / aptX HD / aptX Adaptive / LDAC

Decoding

USB DAC | 768 kHz/32-bit; DSD256 (Native); Full MQA decoding
Coaxial input | 192 kHz/24-bit; DSD64
Optical input | 96 kHz/24-bit
Local playback | 384 kHz/32-bit; DSD256
Streaming playback | 384 kHz/32-bit; DSD256 (DoP)

Digital Output

Coaxial output | 192 kHz/24-bit; DSD64
Optical output | 192 kHz/24-bit

Headphone Output
(Ultra High Gain, THD+N <1%)

32 Ω single-ended | ≥1850 mW + 1850 mW
32 Ω balanced | ≥4000 mW + 4000 mW
300 Ω single-ended | ≥240 mW + 240 mW
300 Ω balanced | ≥950 mW + 950 mW

Line Output

RCA | 2.5 Vrms + 2.5 Vrms (1 kHz @ 10 kΩ)
XLR | 5 Vrms + 5 Vrms (1 kHz @ 10 kΩ)

Audio Parameters

Frequency response | 20 Hz–80 kHz (attenuation <3 dB)
SNR | ≥125 dB (A-weighted)
Noise floor | <2.6 μV (A-weighted)
THD+N | <0.0052% (1 kHz / -8 dB @ 32 Ω)