FiiO K15 Review: A $549 Streaming DAC & Headphone Amp That Punches Above Its Price

Powerful internals, flexible connectivity, and Roon-ready smarts — the K15 is FiiO’s answer to WiiM, and then some.

One Box to Rule Them All

FiiO’s latest release, the K15, is more than a DAC. It’s a streaming-capable desktop powerhouse that combines a high-end dual-mono DAC, a versatile headphone amplifier, and pre-amp functionality — all in a sleek chassis priced at just $549 USD / €599 / £499.

Positioned to challenge devices like the WiiM Ultra and Topping DX9, the K15 borrows key technology from the higher-end FiiO K17, offering an impressive spec list that makes it hard to ignore.

Connectivity & Control

The K15 brings extensive I/O, both analog and digital:

Rear Panel:

• Analog In: RCA + 4.4mm balanced

• Analog Out: RCA + XLR (for preamp or DAC-only use)

• Digital In:

  • USB-C

  • USB-A

  • Optical (TOSLINK)

  • Coaxial

  • Bluetooth (aptX HD, LDAC)

  • Ethernet + Dual-Band Wi-Fi (2.4GHz / 5GHz)

    
    

The unit supports AirPlay 2, Roon Ready streaming, and functions as a network DAC via wired or wireless LAN. It’s a future-facing hub that plays well in any digital ecosystem.

Front Panel Functionality

• 3 headphone outputs:

  • ¼-inch (unbalanced)

  • 4.4mm balanced

  • XLR balanced

• Operational mode switch: Toggle between headphone out, line out, or preamp out

• 5-stage gain control: Tailor output to IEMs or power-hungry planar headphones

• Dual rotary controls: Volume + menu navigation

• 4” touch display: UI with optional VU meter display

  
  

The front panel is clean, intuitive, and designed for quick adjustments without needing to reach for an app — though there’s full control via the FiiO Control app, including parametric EQ.

Dual-Mono DAC Architecture

FiiO’s K15 is one of the first audio devices to implement AKM’s new AK4497S DAC chips — part of the “Velvet Sound” series — in a dual-mono layout. This configuration feeds a fully balanced, differential signal path, promising high SNR, channel separation, and low THD.

Inside, FiiO’s “tri-board architecture” separates:

• Analog circuitry

• Digital processing

• Power supply regulation

  
  

Each subsystem has its own PCB, isolating noise and improving signal integrity. The result? Cleaner sound, better dynamics, and lower distortion.

Sound Shaping and Software

Through the FiiO Control app, users can fine-tune their experience using a 10-band parametric EQ. Whether you're a measurement-focused purist or a musical tweaker, the K15 lets you personalize your listening to taste.

K15 Key Specs at a Glance

Feature	Description
DAC Chips	Dual AKM AK4497S (Velvet Sound series)
Headphone Amp Output	Up to 3W Class A/B via balanced outs
Streaming Support	Roon Ready, AirPlay 2, Bluetooth LDAC/aptX HD
Inputs	USB-A, USB-C, Optical, Coaxial, RCA, 4.4mm
Outputs	XLR, RCA, ¼”, 4.4mm, XLR headphone
Control	Touchscreen + dual knobs + app
Price	$549 USD / €599 / £499
Availability	Ships August 1, 2025
Preview	CanJam London, July 19

Final Thoughts

FiiO’s K15 is an impressive all-in-one that delivers a high degree of performance, flexibility, and smart integration at a very competitive price. Its Class A/B headphone stage, Roon Ready streaming, and dual AKM DAC implementation make it a compelling hub for any headphone enthusiast, desktop audiophile, or streaming-centric setup.

Whether you’re building a new system or replacing an aging stack of gear, the FiiO K15 hits well above its weight class — and lands right in the sweet spot of affordability and performance.