FiiO K9 Desktop Headphone Amp/DAC - AKM Edition

The FiiO K9 AKM is a desktop DAC and headphone amplifier built around AKM’s flagship AK4191EQ + AK4499EX DAC combination and a THX AAA 788+ amplifier, with up to 2,000mW per channel into 32Ω from its balanced outputs. It decodes from a computer (now also by USB-C), a phone, optical, coaxial or LDAC Bluetooth, amplifies analogue sources, and doubles as a preamp for active speakers or a power amplifier, in a truly balanced design with a dual-voltage linear transformer. It won a VGP 2024 Summer Life Style award and a HiVi Best Buy 2024 award.

AKM’s flagship DAC combination

The K9 AKM uses AKM’s AK4191EQ + AK4499EX, which separate the digital and analogue sections completely and add AKM’s newly developed “DWA ROUTING” technology to raise the signal-to-noise ratio and reduce noise at all levels. The result is a more realistic, detailed and natural sound, as if you were there with the performers. The circuit is balanced from the DAC to the outputs, with a signal-to-noise ratio of up to 128dB.

A capable THX AAA 788+ amplifier

The THX AAA 788+ amplifier gives at least 2,000mW per channel into 32Ω and 780mW into 300Ω from the balanced outputs (1% THD), and at least 1,500mW into 32Ω from the 6.35mm output, so it drives low- and high-impedance headphones alike with ease. Three hardware gain levels (low, medium and high) match it to everything from sensitive IEMs to demanding full-size headphones.

Electricity is the mother of sound

A dual-voltage linear transformer with four large 4,700µF capacitors supplies clean, continuous power. The digital and analogue sections have separate supplies to reduce interference between them, and every stage of the audio circuit has its own ultra-low-noise LDO regulation. Accurate dual-mode clock management keeps playback precise at every sample rate, up to PCM 768kHz/32-bit and DSD512 over USB.

Hi-res Bluetooth and USB modes

A Qualcomm QCC5124 Bluetooth 5.1 receiver supports LDAC, aptX Adaptive, aptX HD, aptX, aptX LL, AAC and SBC, for high-quality, low-latency sound with music, videos and games. Over USB (a rear Type-B port and a new Type-C port, with an XMOS XUF208), the K9 AKM supports both UAC 2.0, with a driver where needed, and plug-and-play UAC 1.0 for devices such as the PS5; switch between them in the FiiO Control app.

Inputs and outputs for the whole desk

Inputs: USB Type-B and Type-C, optical (96kHz/24-bit), coaxial (192kHz/24-bit), RCA and 4.4mm balanced line in, and Bluetooth. Outputs: 6.35mm, 4.4mm balanced and 4-pin XLR balanced headphone outputs on the front, and RCA and XLR line outputs on the back. Three output modes choose where the sound goes: PO for the front headphone outputs only, PRE for the rear outputs with volume control (for active speakers or a power amp) and LO for the rear outputs at a fixed level.

A weighty knob with RGB light

FiiO’s iconic, weighty volume knob uses ADC curve reconstruction for 120 precise, smooth volume steps with minimal noise and very little imbalance between channels. The RGB lights around it show the sample rate (cyan for 48kHz or below, yellow above 48kHz, green for DSD) or, in Bluetooth mode, the codec.

App control and EQ

Connect the K9 AKM to your phone by Bluetooth and the FiiO Control app gives you seven preset tuning styles and three custom PEQ settings (these work in Bluetooth mode only), six digital filters, status-light settings, channel balance and UAC 1.0/2.0 switching.

Horizontal or vertical, and protected

The all-aluminium body, made by an integrated stretching and CNC process, follows FiiO’s desktop design language and is strong and precisely finished. Lay it flat or stand it upright on the included stand. Three intelligent protections, against overheating, overload and DC, keep it safe.

Good to know

• The transformer is dual-voltage: check the voltage setting (see the voltage selection card) is right for the UK before first use.
• Compared with the standard K9, the AKM edition uses AKM’s flagship DACs, adds a Type-C USB input and has six digital filters.
• In the box: K9 AKM, power cord, 6.35mm to 3.5mm adapter, USB cable, 6 feet pads, spare fuse, vertical stand, quick start guide, voltage selection card and warranty card.