Overview

The FiiO K17 is a desktop DAC, headphone amplifier and network streamer built around AKM's flagship AK4191 and two AK4499EX DAC chips, one AK4499EX per channel. It's for serious headphone listeners who want one box that can stream over the network, take digital and analog sources, drive demanding full-size headphones with up to 4000mW balanced, and feed a separate amp or powered speakers.

The AK4191 and dual AK4499EX run through an 8-channel to 4-channel low-pass filter design for better channel separation. The headphone stage is a fully discrete Class-AB design, an op-amp plus ON Semiconductor MJE243/253 transistor pairs, delivering up to 4000mW per channel into 32 ohms from the 4.4mm and XLR4 balanced outputs and 1850mW from the 6.35mm output, with five gain levels. A custom low-noise transformer with five 4700µF capacitors powers it, TPA7A47/7A33 LDOs act as secondary regulators, and three Accusilicon femtosecond oscillators handle clocking.

The K17 has eight input modes: USB (up to 768kHz/32-bit and native DSD512), coaxial, optical, RCA line in, 4.4mm balanced line in, Bluetooth 5.1 with LDAC and aptX Adaptive, network streaming over Gigabit Ethernet or dual-band Wi-Fi, and local playback from a USB drive. FiiO documents AirPlay and Roon Ready streaming. A 64-bit, 360MHz DSP and ES9821Q ADC let the 31-band PEQ work in every mode, analog inputs included, with Dual Engine Limiter dynamic range and compressor controls. It adds coaxial and optical digital outputs, a trigger input, a 3.93-inch touch display, five knobs and an IR remote.

Simcoe Audio Video Insight

FiiO says the front headphone outputs can play at the same time, but doesn't recommend using two pairs together for long, especially if their impedances are very different, and notes the balanced outputs have more power than the 6.35mm jack. Lower the volume before swapping from full-size headphones to IEMs. Roon Ready needs a Roon Core running on a computer or server on your network. The XLR and RCA line outs make the K17 an easy fit as a source for powered speakers or a separate amp.

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Why the FiiO K17 Stands Out

Buyer's Guide

Who It's For

• The Full-Size Headphone Owner: Needs up to 4000mW balanced.
• The All-In-One Desk Builder: Wants streamer, DAC and amp in one box.
• The EQ-Focused Listener: Wants a 31-band PEQ on every source.

How It Compares

The K17 shares its chassis size and input layout with the FiiO K15. The K17 moves to AKM's AK4191 and dual AK4499EX DACs, a transformer power supply, up to 4000mW balanced instead of 3000mW, and a 31-band PEQ that works on analog inputs too, and adds coaxial and optical outputs and a trigger input.