K17 R2R

Harmony of Sound and Form
The FiiO K17 R2R brings together the warmth of natural wood, advanced digital audio engineering and a comprehensive range of modern streaming capabilities in a sophisticated all-in-one desktop Hi-Fi component. Designed to deliver a rich and engaging listening experience, it combines a proprietary segmented R2R DAC architecture with a powerful Class AB headphone amplifier, extensive connectivity and advanced digital signal processing.

Its distinctive design reflects the same attention to detail found within its audio circuitry. Premium natural wood side panels introduce an organic character to the precision-machined metal chassis, while multiple physical controls and a large touchscreen provide an intuitive way to operate the system. The K17 R2R is designed not simply to reproduce music, but to create an experience that engages both the senses and the emotions.

Proprietary 24+5bit Segmented R2R DAC
At the heart of the K17 R2R is FiiO's proprietary 24+5bit segmented R2R PRO resistor array. This sophisticated architecture combines the advantages of traditional R2R conversion with a segmented design intended to address some of the inherent limitations of conventional resistor ladder DACs.

The upper five bits are decoded using 31 thermometer-coded resistors, helping to reduce error accumulation and minimise distortion. This carefully engineered approach allows the K17 R2R to retain the qualities that make R2R conversion so appealing, delivering a presentation that is clear, smooth, natural and warm.

The result is a highly musical sound that combines impressive detail retrieval with an effortless sense of realism. Rather than emphasising technical precision at the expense of musicality, the K17 R2R is designed to preserve the richness and texture of recordings, making it equally suited to detailed critical listening and relaxed extended sessions.

The Warmth of Real Wood
The K17 R2R combines FiiO's classic square-and-round design language with premium natural wood detailing. The side panels are available in imported white ash or black walnut, depending on the chassis finish, creating two distinctive interpretations of the component's retro-inspired aesthetic.

The silver chassis paired with white ash delivers a crisp and understated appearance, while the black chassis combined with black walnut creates a deeper and more sophisticated look. The natural grain of the solid wood contrasts beautifully with the precision finish of the metal chassis, giving every K17 R2R an individual character. As natural wood grain is unique to every piece, the appearance of each unit will vary.

The design is not purely decorative. Multiple physical knobs provide smooth and intuitive access to important controls, while the carefully designed grille structure assists with heat dissipation, helping the component maintain stable operating temperatures during extended listening.

Play Music from Almost Anywhere
The K17 R2R is designed to accommodate modern streaming services, local music collections and traditional wired sources. With support for Roon Ready, AirPlay and Qplay, it integrates naturally into a wide range of digital audio systems and allows music to be streamed from compatible devices and platforms.

The addition of NAS playback brings locally stored music libraries into the system, with support for both NFS and SMB protocols. Through the FiiO Control app, users can access compatible network storage and browse their personal music collections directly.

Whether music is being streamed from the cloud, played from a NAS server or accessed from local storage, the K17 R2R provides a flexible route to high-quality digital playback.

Eight Versatile Operating Modes
The K17 R2R offers eight distinct operating modes, allowing it to perform as the central component of a wide variety of Hi-Fi systems. In streaming receiver mode, it can receive music through Roon Ready, Qplay or AirPlay. Local playback mode provides access to music stored on connected storage devices or network-attached storage.

For traditional Hi-Fi sources, the K17 R2R can accept both single-ended and balanced analogue inputs before amplifying the signal. USB decoding provides high-resolution playback through the integrated XMOS 16-core XU316 processor, supporting PCM up to 32-bit/768kHz and DSD256 alongside full MQA decoding.

Bluetooth decoding is handled by the Qualcomm QCC5125 platform, supporting Bluetooth 5.1 together with aptX HD, aptX Adaptive and LDAC. Optical and coaxial inputs provide additional options for connecting digital sources, making the K17 R2R an exceptionally versatile component for both modern and traditional systems.

A Mixing Console for Desktop Hi-Fi
The K17 R2R goes considerably beyond conventional streaming DACs by incorporating an extensive suite of digital signal processing tools. Its 31-band high-precision lossless parametric equaliser provides detailed control over the sound while maintaining a high level of audio fidelity.

A dedicated M21586Q DSP processor performs double-precision 64-bit floating-point calculations at a 360MHz clock frequency. It works alongside an ES9821Q ADC and a customised ultra-low phase noise femtosecond crystal oscillator, creating the processing platform required for sophisticated equalisation and signal management.

The PEQ system can be used to correct or customise headphone frequency responses, giving users precise control over their listening experience. Settings can be exported, imported, shared and saved, making it possible to create and manage different profiles for individual headphones.

31-Band Lossless PEQ
FiiO's advanced PEQ system provides extensive control over the audio signal, with gain adjustment ranging from +12dB to -24dB and Q values ranging from 0.4 to 128. PCM signals from 44.1kHz to 96kHz can be processed without sample rate conversion, allowing detailed adjustments while retaining the original sampling rate.

The system incorporates FiiO's Dual Engine Limiter technology and proprietary algorithms, enabling functions including dynamic range compression, dynamic range expansion, limiting and compression. This gives experienced users extensive control over the characteristics of their headphones and allows the K17 R2R to be used for both precise correction and creative sound shaping.

AUTO EQ for Effortless Personalisation
For listeners who prefer a simpler approach to equalisation, the K17 R2R supports AUTO EQ. This system can automatically match compatible headphones to a selected target frequency response, allowing users to create a personalised listening profile with a single operation.

Built-in presets for Pop, Jazz and Classical music provide convenient starting points, while users retain the ability to fine-tune individual frequency bands manually. This combination of automated correction and detailed manual adjustment makes it possible to achieve a highly personalised sound without requiring extensive knowledge of equalisation.

Discrete Class AB Headphone Amplification
A powerful fully discrete Class AB headphone amplifier forms another key part of the K17 R2R's design. The amplifier uses an OP plus transistor current amplification architecture incorporating ON Semiconductor MJE243 and MJE253 transistors.

This discrete topology is designed to deliver high current alongside low output impedance, allowing the K17 R2R to drive a wide variety of headphones and in-ear monitors with authority. In balanced mode, the amplifier can produce up to 4000mW + 4000mW of output power, providing substantial reserves for demanding headphones while retaining the refinement required for sensitive IEMs.

The resulting presentation combines power with smoothness and natural musicality, allowing the K17 R2R to accommodate everything from efficient in-ear monitors to more demanding full-size headphones.

Fully Balanced Audio Architecture
The K17 R2R employs a fully differential architecture throughout its principal audio path. The balanced design extends from the DAC through the I/V conversion and low-pass filtering stages to the headphone amplifier, maintaining the benefits of balanced signal processing throughout the circuit.

This architecture helps achieve high dynamic range while significantly reducing crosstalk. Multiple low-noise precision Texas Instruments operational amplifiers are used within key sections of the audio circuit, including the I/V conversion and low-pass filter stages, helping maintain clean and dynamic audio reproduction.

Physically Separated Circuit Boards
Internal circuit layout has been carefully considered to minimise unwanted interference between the different sections of the K17 R2R. The power supply, digital circuitry and analogue circuitry are positioned on physically separated circuit boards, helping prevent noise generated by one section from affecting another.

This separation is particularly important in a component that combines high-speed digital processing, network connectivity, DAC conversion and high-power headphone amplification. By keeping these sections isolated, the K17 R2R is able to maintain greater signal integrity and provide a cleaner, purer audio output.

Precision Power Supply Design
A custom 35W low-noise linear power supply provides the K17 R2R with a clean and stable source of power. The high-quality transformer is designed to minimise unwanted noise, while five large 4700μF electrolytic capacitors provide substantial energy reserves for demanding musical passages and high-current amplification.

The digital and analogue circuits use separate power supplies to help prevent interference and crosstalk between the two domains. The analogue audio circuitry also benefits from a multi-stage power supply architecture, with dedicated power control used for important sections including the digital-to-analogue conversion and low-pass filtering stages.

Low-noise, high-PSRR TPA7A47 and TPA7A33 LDO regulators provide additional regulation, helping deliver stable and clean power throughout the analogue circuitry.

Three Ultra-Low Phase Noise Femtosecond Oscillators
Accurate clocking is essential to precise digital audio reproduction, and the K17 R2R incorporates three ultra-low phase noise femtosecond audio crystal oscillators. Two ACCUSILICON AS318-L oscillators operate at 45.1584MHz and 49.1520MHz, while a FiiO-customised ultra-low phase noise 12MHz oscillator provides additional timing precision.

By significantly reducing phase noise and improving clock stability, this carefully engineered clocking system helps digital signals of different sampling rates to be reproduced with greater accuracy. The result is a cleaner and more consistent presentation with improved timing, focus and detail.

Premium Audio Components
The K17 R2R uses a carefully selected collection of high-quality components throughout its audio and power supply circuitry. Four Nichicon audio-specific capacitors, four ELNA SILMIC II capacitors, six ELNA RA3 audio capacitors and four WIMA audio-specific capacitors contribute to the analogue signal path and power supply design.

Eight Panasonic film capacitors and 32 chip resistors provide further attention to low noise and temperature stability, helping maintain consistent performance across changing operating conditions. Rubycon solid capacitors provide ultra-low ESR and strong interference rejection for stable power delivery.

Signal connections between internal circuit boards use four sets of silver-plated oxygen-free copper cables, helping minimise transmission losses. NEUTRIK gold-plated connectors provide reliable, durable connections with strong resistance to oxidation and wear.

Dual-Core Processing Architecture
The K17 R2R uses a high-performance X2000 multi-core processor to manage demanding audio processing and system functions efficiently. Its architecture incorporates an XBurst2 CPU core with two logic CPUs and an additional XBurst small core, providing substantial processing capability while maintaining efficient power consumption.

A dedicated ESP32-S3 SoC provides further processing resources for the user interface and connectivity functions. Its dual-core Xtensa 32-bit LX7 processor can operate at up to 240MHz and is complemented by an ultra-low-power co-processor, helping deliver a responsive and fluid user experience.

Intuitive Touchscreen Control
A 3.93-inch LCD touchscreen provides direct access to the K17 R2R's extensive range of functions and settings. The display allows users to adjust playback, gain, equalisation and other system parameters without needing to navigate complicated menus.

Five physical control knobs complement the touchscreen, providing tactile access to important functions including volume and gain adjustment. A single press can place the K17 R2R into standby, while the physical controls provide a familiar and satisfying method of interacting with the component.

An aluminium alloy infrared remote control is also included, allowing users to change operating modes, select EQ profiles and adjust volume from a comfortable listening position.

Intelligent App Connectivity
The FiiO Control app provides additional control over the K17 R2R and expands its functionality beyond the front panel. Through the app, users can access local music playback and NAS multimedia services while managing various settings and system functions.

This combination of touchscreen, physical controls, remote control and app-based operation gives the K17 R2R exceptional flexibility, allowing users to interact with the component in whichever way best suits their listening environment.

Wired and Wireless Network Connectivity
A Gigabit Ethernet connection provides fast and stable wired network performance for high-resolution music streaming and NAS playback. For systems where a wired connection is less practical, the integrated AP6256 Wi-Fi module supports both 2.4GHz and 5GHz networks.

This combination provides reliable access to lossless digital audio while giving users the flexibility to position the K17 R2R wherever it is most convenient within a desktop or Hi-Fi system.

Comprehensive Protection
The K17 R2R incorporates multiple protection systems designed to safeguard both the component and connected equipment. Temperature protection monitors the headphone amplifier and transformer, while output overload and output DC protection help prevent potentially damaging conditions.

Power input overcurrent protection provides an additional layer of security, allowing the K17 R2R to monitor abnormal operating conditions and respond automatically when necessary. These systems provide reassurance during demanding listening sessions and help protect connected headphones, IEMs and other audio equipment.

A Truly Versatile All-in-One Hi-Fi Component
The FiiO K17 R2R combines an advanced R2R DAC, high-power discrete headphone amplifier, network streamer, analogue preamplifier and sophisticated PEQ platform into a single desktop component. Its extensive connectivity allows it to sit at the centre of a wide variety of systems, from computer-based headphone setups to complete two-channel Hi-Fi systems.

A computer can be connected through USB while headphones and active speakers are connected simultaneously. A NAS can provide access to a personal music library, while Roon Ready and AirPlay allow convenient network streaming. The K17 R2R can also receive analogue signals from external digital music players, decode music from USB storage or operate as a high-performance source component connected to an amplifier and passive speakers.

With its combination of proprietary 24+5bit segmented R2R conversion, powerful Class AB amplification, advanced lossless PEQ, comprehensive network functionality and distinctive natural wood construction, the FiiO K17 R2R offers a sophisticated and highly flexible approach to modern desktop Hi-Fi. It is designed for listeners who want the warmth and musicality of R2R conversion alongside the convenience, control and connectivity expected from a contemporary high-end digital audio system.