K9

About the K9

The FiiO K9 is a compact desktop DAC and headphone amplifier designed for audiophiles and music enthusiasts. It uses two ES9068AS DAC chips to handle left and right channels separately, delivering rich, detailed sound with high dynamic range and low distortion. The amplifier section features dual THX AAA 788+ modules, providing up to 2000mW output at 32Ω and 780mW at 300Ω, suitable for driving a wide range of headphones from low-impedance IEMs to power-hungry planar magnetic headphones. The device supports multiple inputs including USB-B, optical, coaxial, RCA, and 4.4mm, and outputs including 1/4", balanced 4.4mm, 4-pin XLR, RCA, and balanced XLR-3. It offers selectable gain levels (low, medium, high) and multiple output modes (LO, PRE, PO) for versatile use with headphones and active speakers. The K9 features a fully balanced architecture with partitioned PCB layout and isolated power supplies for analog and digital sections to minimize interference and crosstalk. It supports high-resolution audio playback up to 32-bit/768kHz PCM and DSD512, and includes Bluetooth 5.1 with support for LDAC, aptX HD, aptX Adaptive, and other high-res codecs. The device is controlled via the FiiO Control app, allowing filter selection, channel balance adjustment, and firmware upgrades. Its power supply uses a linear design with large capacitors and multiple ultra-low-noise LDO regulators to ensure stable, clean power delivery for superior sound quality.