The Fostex HP-A3 Mk2 combines a headphone amplifier and a digital-to-analog converter in one machine. The device draws the required power via the USB-C connection, which also enables mobile use. The HP-A3 Mk2 is capable of converting optical digital audio signals and USB audio into analog signals and outputting them via the line output or the headphone output.
The sound quality has been significantly improved compared to the original model thanks to the new DAC chip. The chip now supports a sampling rate of 192 kHz at 24 bits, which results in fewer errors during the sampling process and optimizes the listening experience. To ensure that this sampling frequency works without problems, Fostex has redeveloped the analog circuitry and modified it in such a way that improved THD values and low noise are also achieved.
The headphone output gain of the HP-A3 Mk2 can be adjusted with the "HI/LO" switch, whereby the HI position increases the volume of the signal by 10dB more than the LO position. It is advisable to set the switch to "HI" if input signals with a low level are to be processed.