FiiO K15 Hi-Fi Kopfhörerverstärker Silver

Desktop DAC and Headphone Amplifier with Built-In Streamer

The FiiO K15 Silver is a full-size desktop DAC and headphone amplifier built around dual AKM AK4497S Velvet Sound DAC chips and a discrete Class-AB headphone output stage. It is engineered as an all-in-one reference unit: USB DAC, network streamer, Bluetooth receiver, and high-current headphone amplifier in one chassis. The fully balanced audio path runs from DAC decoding through low-pass filtering, gain control, and the headphone amplifier, keeping crosstalk and noise to a minimum. For listeners building a single-source desktop rig, this model consolidates decoding, amplification, and streaming without compromise.

What Sets the K15 Apart in the Desktop DAC Category

Two flagship-grade AKM AK4497S chips run in dual-mono mode, paired with two Accusilicon AS318-L femtosecond crystal oscillators at 45.1584 MHz and 49.1520 MHz for ultra-low jitter. The discrete Class-AB headphone stage uses an op-amp plus transistor current-boosting topology with an ON Semiconductor MJE243G/253G complementary pair, a design choice rarely seen at this price tier. Power delivery comes from a 30 W industrial-grade switch-mode supply with 14 low-dropout linear regulators feeding separate digital and analog rails, with the analog section further split into DAC, LPF, and transistor stages for cleaner power isolation.

DAC Architecture and Decoding Performance

Decoding quality defines the ceiling of any desktop DAC, and this instrument pushes that ceiling with two of AKM's newest 32-bit Velvet Sound chips. Each stage of the digital-to-analog chain is differential, which preserves dynamic range and channel separation even at low listening levels.

• DAC Chipset: 2x AKM AK4497S (AK4479SVQ) — flagship Velvet Sound silicon in dual-mono configuration
• USB Decoding: up to 768 kHz / 32-bit and DSD512 (Native) — handles the highest-resolution studio masters
• Clean digital passthrough from a transport is provided via the coaxial input, supporting up to 192 kHz / 24-bit and DSD64.
• Optical Input: up to 96 kHz / 24-bit — for TV, game console, or CD player sources
• Streaming & Local Playback: up to 384 kHz / 32-bit and DSD256 (DoP) — covers Roon, AirPlay 2, and USB drive playback

Headphone Amplification and Power Delivery

Headphone drive capability is where many desktop DACs fall short, but the discrete Class-AB stage here is built for everything from sensitive in-ear monitors to power-hungry planars. Five gain levels let users match the output to the headphone, and the balanced topology keeps the noise floor low enough for high-sensitivity IEMs.

• Balanced Output Power: 2800 mW + 2800 mW at 16 Ω; 1400 mW + 1400 mW at 32 Ω; 180 mW + 180 mW at 300 Ω — drives full-size over-ears and planars with authority
• Headphone Outputs: 4.4 mm balanced, XLR4 balanced, 3.5 mm single-ended, XLR3-pin balanced — covers every common headphone termination
• Users can choose between 5-level adjustable gain settings, ensuring clean pairing with both IEMs and demanding over-ears.
• Output Transistors: ON Semiconductor MJE243G/253G complementary pair — high-current, low-impedance discrete output stage

Connectivity, Streaming, and Control

Modern desktop listening rarely happens through one cable, so this unit ships with wired, wireless, and local playback paths. A 3.93-inch bezel-less touchscreen, an infrared remote, and the FiiO Control app cover every control style, while a 10-band parametric EQ lets users tune the response to specific headphones.

• Bluetooth Codecs: SBC, AAC, aptX, aptX LL, aptX HD, aptX Adaptive, LDAC — high-resolution wireless from any modern source device
• Network: Gigabit Ethernet + 2.4G/5G dual-band Wi-Fi (AP6256) — stable wired or wireless streaming
• Streaming Support: Roon Ready and Apple AirPlay 2 — integrates into multi-room and library-driven setups
• Display: 3.93-inch LCD touchscreen (240 x 1020) — direct on-device control without the app
• Parametric EQ: 10-band high-precision PEQ on all digital inputs — headphone-specific tuning via FiiO's web-based PEQ tool

Who the K15 Is For

This model is the right choice for desktop audiophiles who want a single component to replace a stack of separates. Listeners running full-size planar magnetics, high-impedance dynamics, or sensitive in-ear monitors will all find a usable gain setting, and the 3000 mW balanced headroom means even stubborn headphones come alive. It also suits users who stream from Roon or AirPlay 2 libraries and want the DAC, streamer, and headphone amp to live in one chassis.

Build Quality and Physical Design

The chassis measures roughly 244.6 x 213 x 66.8 mm and weighs about 2100 g, with a grid-pattern side panel that doubles as a heat sink for the Class-AB output stage. Internal boards are physically separated into power supply, digital, and analog sections, and the various boards are wired together with silver-plated oxygen-free copper interconnects. Component selection includes two Nichicon 3300 µF audio caps, four ELNA SILMIC II, eight ELNA RA3, eight ruby film caps, and Beryl ultra-low-ESR units, supported by 32 wafer resistors for thermal stability.