Fostex HP-A3mk2 USB DAC – Headphone Amplifier

TheHP-A3mk2is a USB DAC that operates on USB bus power. USB audio and optical digital audio signals from a PC can be converted to analog signals and output from the line output and headphone output. It operates with the USB Audio 2.0 driver of a PC (Windows or Mac OS), and can be used immediately after connecting the USB cable and performing with simple settings.

• ES9016K2M from ESS Technology is used as the DAC chip
• Using the high-quality DAC chip, supported sampling frequency has been greatly enhanced to 192 kHz. Users can enjoy higher quality sound without sacrificing ease of use.
• The analog circuitry has been newly designed to match the higher supported sampling frequency, and has achieved performance of high-end products, including improved THD (total harmonic distortion).
• Gain switch to accommodate various playback sources
• The headphone output amplifier gain can be switched between HI and LO positions.
• The HI position provides 10 dB increase in volume over the LO position. The HI position is effective for low-level input signals and can be used with a variety of playback sources.

Specifications:

Inputs
[USB] terminal

• Connector: USB Type-C
• Interface: USB 2.0 Hi Speed
• Supported OS: Windows 10, Mac OS CatalinaOS 10.15or later
• Sampling Frequencies: PCM Max. 192 kHz
• [Digital In] terminal
• Connector: Optical, Square
• Format: S/PDIF (32 kHz 96 kHz)

Outputs
[PHONES] terminal

• Connector: Standard 6.3 mm stereo phone jack
• Maximum output: 100 mW (32 ohm), 20 mW (300 ohm)
• Load impedance: more than 16 ohm
• THD: less than 0.03 % (at 32 ohm, 1 kHz 100 mW output)
• Frequency Response: 20 Hz 20 kHz +/-3dB

[ANALOG OUTPUT L, R] terminal

• Connector: RCA pin jack
• Maximum output: 2 Vrms (0 dBFS VRMAX)
• Applicable load impedance: more than 10 k ohm
• THD: 0.005 % (at 1kHz)
• Frequency Response: 20 Hz 20 kHz +/-3dB

[DIGITAL OUTPUT] terminal

• Connector: Optical, Square
• Format: S/P DIF

General

• Accessories: USB Cable (Type-A to Type-C, 1 m) x 1, Rubber foot x 4
• Measurements: 34(H) x 113 (W) x 155(D) mm, including protrusion, excluding feet
• Weight: approx. 500 g
• Power supply: DC 5 V, from USB terminal
• Power consumption: 2.5 W