HiBy FD3 II Adds Dual CS4302 DACs and Class A Power to the Desktop

HiBy has introduced the FD3 II, a desktop DAC and headphone amplifier built around two CS4302 converters. The compact component combines USB and Bluetooth inputs with balanced and unbalanced headphone connections, dedicated line outputs and switchable Class A or Class AB operation.

Dual-DAC digital architecture

The FD3 II assigns one CS4302 DAC to each channel, providing separate digital-to-analog conversion for the left and right sides. Its USB input supports PCM playback at resolutions up to 768 kHz/32-bit, alongside DSD512 and MQA 8X decoding.

Users can select between USB Audio Class 1 and USB Audio Class 2 modes. UAC2 accommodates the FD3 II’s higher-resolution capabilities when used with compatible equipment, while UAC1 provides an alternative for computers and other devices that require the older USB audio standard.

HiBy has also fitted two low-phase-noise clocks running at 45.1584 MHz and 49.152 MHz. The separate clock frequencies serve the commonly used digital-audio sample-rate families rather than relying on a single clock for every incoming format.

Switchable Class A and Class AB amplification

The headphone amplifier can operate in either Class A or Class AB, allowing the user to select the amplification mode from the device. Maximum output is specified at 1,125 mW per channel into a 32-ohm load.

OPA1652 operational amplifiers form part of the internal design, while the 12 V DC power arrangement is fully isolated. Active cooling is included to maintain stable operation under load.

Headphones connect through a 3.5 mm unbalanced socket or a 4.4 mm balanced output on the front panel. The 3.5 mm connection supports standard TRS plugs as well as CTIA-format TRRS headset plugs. Volume is controlled in hardware across 100 steps, rather than being limited to software adjustment from the connected playback device.

USB, Bluetooth and line-level connectivity

In addition to its wired USB input, the FD3 II can receive audio over Bluetooth. Supported codecs are SBC, AAC, LDAC and HiBy’s UAT. The wired and wireless implementations carry Hi-Res Audio and Hi-Res Audio Wireless certifications, respectively.

Separate 3.5 mm and 4.4 mm line outputs allow the FD3 II to feed another audio component. This gives the unit a role beyond direct headphone listening, enabling its DAC section to serve an amplifier or another device with a suitable analog input.

Compact desktop construction

The FD3 II measures 115 × 115 × 52.7 mm and weighs 698 g. HiBy combines a metal enclosure with a glass top panel, while a 1.1-inch color OLED display provides visual information on the unit’s operating status. A physical volume knob handles the 100-step level control.

Included accessories comprise a USB-A-to-USB-C cable, a 3.5 mm male-to-6.35 mm female adapter, a 12 V external power supply and documentation. The FD3 II is listed for purchase through AliExpress, although no USD price has been specified.

With dual CS4302 DACs, broad high-resolution format support, Bluetooth reception and two amplifier operating modes, the HiBy FD3 II brings several source and headphone-driving functions together in a small desktop enclosure.