FiiO K17 black

The K17 marks a significant milestone in the evolution of FiiO’s desktop range, combining a next-generation dual AKM DAC architecture with fully discrete amplification and a 31-band parametric equalizer. This desktop unit offers a versatile approach to high-resolution audio processing, capable of serving as a headphone amplifier, digital-to-analog converter, hi-fi preamplifier, or network player.

Neo-vintage design and modern touch interface

The K17 adopts a distinctive aesthetic blending classic cues with contemporary technologies. Its compact aluminum chassis (24.46 x 21.3 x 6.68 cm, weighing 2.75 kg) features a front panel dotted with metal knobs and physical switches, reminiscent of traditional hi-fi equipment. This retro approach is enhanced by modern touches: the potentiometers are accented with customizable RGB LEDs, while a 3.93-inch color touchscreen sits at the center of the front panel.

The touch interface displays essential information—active source, audio format, volume level—and can transform into analog VU meters. The five physical rotary knobs provide direct control over main functions, offering a hybrid ergonomics between touch operation and traditional controls. The structured ventilation grille ensures efficient heat dissipation while contributing to the device’s visual identity.

Dual AKM DAC architecture and advanced digital processing

At the heart of the K17, FiiO has implemented a dual DAC configuration based on two AK4499EX chips managed by an AK4191 controller. This architecture separates digital and analog processing to minimize interference, with each channel handled by a dedicated DAC in an 8-channel to 4-channel topology. The DWA ROUTING technology developed by AKM reduces background noise while improving resolution.

The clock management system relies on three Accusilicon femtosecond oscillators—two AS318-L (45.1584MHz and 49.1520MHz) and one AS318-Pro (24.576MHz)—ensuring ultra-low jitter. This temporal precision enables faithful reproduction of audio signals up to 32 bits / 768 kHz in PCM and native DSD512. The main X2000 multi-core processor, supported by an ESP32-S3 SoC, ensures smooth and responsive user interface processing.

Discrete amplification and sophisticated power management

The K17’s amplification stage is based on a fully discrete class AB architecture, using ON Semiconductor MJE243 and MJE253 power transistors. This high-current design delivers considerable power: up to 4000 mW per channel at 32 ohms in balanced mode (4.4 mm and XLR outputs) and 1850 mW in unbalanced mode (6.35 mm output).

The 35W linear power supply, combined with five 4700 μF capacitors, provides a stable and clean current reserve. Each section of the audio circuit benefits from dedicated low-noise TPA7A47/7A33 voltage regulators, ensuring optimal power delivery to each stage. This multi-stage approach with separate digital and analog power supplies helps maintain an exemplary signal-to-noise ratio, reaching 125 dB on the XLR outputs.

Lossless 31-band parametric equalizer

One of the K17’s standout features is its 31-band parametric equalizer (PEQ), a rarity in this type of equipment. Managed by a 360 MHz M21586Q DSP chip capable of 64-bit double-precision floating-point calculations, this equalizer offers surgical control over the response curve without introducing audible distortion.

Unlike traditional graphic equalizers limited to fixed frequencies, the K17’s PEQ allows adjustment of three parameters for each band: center frequency, gain (boost or cut), and Q factor determining the affected bandwidth. This flexibility enables highly precise corrections tailored to the specific characteristics of a headphone or personal preferences. Equalization profiles can be saved and shared, creating a community of users exchanging their optimized settings.

Comprehensive connectivity and network features

The K17 stands out for its particularly rich connectivity. Inputs include three USB-C ports (one on the front), a USB-A for external storage, optical and coaxial digital inputs, as well as an RCA line-in and a balanced 4.4 mm input. Headphone outputs include a 6.35 mm unbalanced jack, a 4.4 mm balanced jack, and a 4-pin XLR balanced output. For integration into a hi-fi system, RCA and XLR line outputs are available, complemented by optical and coaxial digital outputs.

The network section features Bluetooth 5.1 via a Qualcomm QCC5125 chip supporting LDAC, aptX HD, aptX Adaptive, and aptX Low Latency codecs. Dual-band Wi-Fi and the Ethernet port allow access to files stored on NAS via the FiiO Control app. The K17 is AirPlay 2 compatible and Roon Ready certified, making it easy to integrate into sophisticated multiroom audio ecosystems.

Evolution compared to the K9 Pro

The K17 succeeds the K9 Pro with several substantial improvements. While the K9 Pro used either a single AK4499 DAC (limited edition) or two ES9038 PROs (ESS version), the K17 adopts the newer dual AK4499EX configuration with the AK4191 controller. The K9 Pro’s THX AAA amplification is replaced by a fully discrete architecture offering higher power and a potentially more organic sound signature.

The addition of the 31-band PEQ equalizer is a major difference, as the K9 Pro was limited to preset profiles. The color touchscreen replaces the predecessor’s monochrome display, significantly enhancing the user experience. The included remote control and five gain levels (-24 dB to +12 dB) further increase the K17’s versatility.

Technical Specifications

General Information

• Balanced headphone output up to 4000 mW + 4000 mW
• Dual DAC AK4499EX + AK4191 for precise and natural sound
• 31-band lossless equalizer (PEQ): fine-tune your sound like a pro
• 3.93” touchscreen + 5 rotary buttons for intuitive control
• Comprehensive connectivity: USB, Bluetooth, Wi-Fi, Ethernet, optical, coaxial, RCA, XLR
• MQA: compatible with high-resolution audio files
• Remote control: remote included

Built-in Technologies

• AKM DAC: AK4191 + 2 × AK4499EX
• Discrete amplification: MJE243 / 253 transistors
• 31-band PEQ equalizer: with profile simulation and sharing
• X2000 and ESP32-S3 processors: smooth performance, stability, and low latency
• Accusilicon femtosecond oscillators: ultra-low jitter
• 35 W linear power supply + 5 × 4700 μF capacitors for stable current

Connectivity

Inputs

• USB: Type-C × 3, USB-A × 1
• Optical / coaxial
• RCA line-in / 4.4 mm line-in
• Bluetooth 5.1: LDAC, aptX HD, aptX Adaptive
• Wi-Fi 2.4 G / 5 G
• Ethernet

Outputs

• 3.5 mm / 6.35 mm headphone
• Balanced headphone 4.4 mm / XLR4
• RCA line-out (unbalanced)
• XLR line-out (balanced)
• Optical / coaxial

Audio Performance

6.35 mm Headphone Output (USB DAC - ultra high gain)

• Power: 1850 mW + 1850 mW @ 32 Ω
• THD+N: < 0.0005%
• Signal-to-noise ratio: ≥ 124 dB

Balanced Headphone Output (4.4 mm / XLR4)

• Power: up to 4000 mW + 4000 mW @ 32 Ω
• THD+N: < 0.00049%
• Crosstalk: ≥ 119 dB

RCA Line Output

• Level: 2.5 Vrms
• THD+N: < 0.00053%
• SNR: ≥ 121 dB

XLR Line Output

• Level: 5 Vrms
• THD+N: < 0.00045%
• SNR: ≥ 125 dB

Box Contents

• FIIO K17
• Remote control
• Power cable
• Headphone adapters
• USB cables
• Quick start guide