FiiO K17 R2R - Black - Silver

Description

FiiO's flagship desktop digital hub

The K17 R2R acts as a true desktop command center, fusing three roles: high-resolution DAC, high-current headphone amplifier and versatile network streamer. Everything sits in an aluminum chassis flanked by precision-machined North American hardwood side panels — white ash for the silver version, black walnut for the black one. A 3.93-inch bezel-less LCD touchscreen and five control knobs provide direct access to every setting, playback data and network configuration; an aluminum-alloy IR remote is included for remote control.

24+5-bit segmented R2R PRO architecture

At the heart of conversion sits FiiO's proprietary 24+5-bit segmented R2R PRO resistor array. Traditional R2R designs often suffer from cumulative errors at the highest bits, which can compromise accuracy. FiiO addresses this by isolating the upper 5 bits and routing them through 31 thermometer-coded resistors. This segmented approach lowers distortion and preserves the smooth, full-bodied presentation R2R is loved for, while raising technical precision. Clocking is handled by three ultra-low phase noise femtosecond oscillators, including two ACCUSILICON AS318-L (45.1584 and 49.1520 MHz) and one FiiO-customized 12 MHz oscillator.

Fully discrete Class AB amplification: 4,000 mW + 4,000 mW

The headphone amplifier stage is fully differential and fully discrete, built around an OP+ transistor topology with the classic ON Semiconductor MJE243/MJE253 pair. It delivers high current with very low output impedance. Power: up to 4,000 mW + 4,000 mW into 32 Ω balanced (nearly double the K9 Pro ESS). Five gain levels (Low to Ultra High) let you drive demanding planar magnetic headphones as confidently as highly sensitive in-ear monitors — adaptive-impedance handling (8 – 150 Ω SE / 8 – 350 Ω balanced) simplifies matching.

Lossless 31-band PEQ, AUTO EQ and double-precision DSP

An M21586Q DSP performs 64-bit floating-point calculations at 360 MHz, and paired with an ES9821Q ADC, enables a 31-band lossless parametric equalizer available in every operating mode. AUTO EQ automatically matches the target curve for your headphones in one click. Pop, Jazz and Classical presets included. Gain range +12 to -24 dB, Q values from 0.4 to 128. DEL (Dual Engine Limiter) technology adds DRC/DRE/limiter/compressor processing. PCM 44.1 to 96 kHz signals are processed with no sample-rate conversion.

8 operating modes, full native networking

The K17 R2R adapts to any source through eight modes: USB DAC (XMOS XU316, up to 768 kHz / 32-bit, DSD256), coaxial decoding (192 kHz / 24-bit), optical decoding (96 kHz / 24-bit), line-in, balanced 4.4 mm line-in, Bluetooth 5.1 receiver (SBC/AAC/aptX/LDAC via QCC5125), network streaming and local playback. On the network side: Roon Ready, Apple AirPlay and Qplay natively, plus NAS playback via NFS and SMB. Dual-band 2.4/5 GHz Wi-Fi (AP6256) and Gigabit Ethernet. The FiiO Control app (iOS/Android) manages every setting.

35 W linear power supply and comprehensive connectivity

The power supply relies on a custom 35 W low-noise linear transformer, backed by five 4,700 µF electrolytic capacitors and TPA7A47/7A33 LDO regulators. Digital and analog power supplies are physically separated on different boards. Front: 6.35 mm, 4.4 mm and 4-pin XLR headphone outputs. Rear: balanced XLR3 (5 Vrms) and unbalanced RCA (2.5 Vrms) line outputs, coaxial and optical digital inputs, RCA and 4.4 mm balanced analog inputs, coax and optical digital outputs, USB-A, two USB-C, Gigabit Ethernet, Trigger In. Built-in protections: headphone amp and transformer temperature, overload, output DC, input overcurrent. Dimensions: 244.6 × 213 × 66.8 mm; 2.75 kg.

Frequently Asked Questions (FAQ)

What's the difference between the K17 R2R and the standard K17?

Both share the same chassis, the same discrete Class AB amplification (4,000 mW balanced), the same 3.93-inch touchscreen, the same network platform (Roon Ready, AirPlay, Qplay, NAS) and the same 31-band PEQ. The difference lies in the DAC: the standard K17 uses a dual AK4499EX + AK4191EX (semiconductor delta-sigma architecture), while the K17 R2R uses FiiO's proprietary 24+5-bit segmented R2R PRO resistor array. R2R brings a signature typically described as warmer, more natural, more full-bodied; delta-sigma emphasizes analytical precision and high-frequency extension.

Does the R2R PRO architecture sound different from a standard delta-sigma DAC?

Yes. Resistor-ladder (R2R) DACs generally produce a presentation described as more natural, smooth and full-bodied compared to delta-sigma alternatives. FiiO's segmented 24+5-bit design preserves this characteristic warmth while using 31 thermometer-coded resistors for the upper bits, dramatically lowering the distortion typically associated with vintage R2R designs.

Is it safe to use highly sensitive IEMs with an amplifier this powerful?

Yes. While the fully discrete Class AB amplifier can deliver up to 4,000 mW into 32 Ω balanced, the unit has five independent gain levels (Ultra High, Super High, High, Medium, Low). Setting the amp to Low gain reduces the output for sensitive IEMs while keeping a very low noise floor, guaranteeing a dark background free of audible hiss at low volumes. Adaptive impedance (8 – 150 Ω SE, 8 – 350 Ω balanced) and built-in protections (DC, overload) also safeguard your earphones.

What's in the Box

FiiO K17 R2R desktop DAC / headphone amplifier / network streamer

AC power cable

USB data cable

Aluminum-alloy infrared remote control

Documentation