Fostex HP-A4 24-Bit DAC/Headphone Amp

The Fostex HP-A4 is an extremely versatile unit.  For starters it's a very clean and powerful headphone amp that can handle nearly all cans with a high/low gain switch adjustment.  It can also be used as a pre-amp for active (powered) speakers using the RCA outputs.  The HP-A4 is both powered by and accepts audio over USB from any computer or laptop, including the highest resolution files at 24/192kHz.  This impressive unit can also accept digital audio through a standard Toslink optical input.  Plus it can act as a stand alone DAC using the digital optical output.  Overall we are impressed with the build and sound quality of the HP-A4 from Fostex.  It should make a perfect all-around device for a computer audiophile. 

Product Features:

  • USB buss powered operation without AC adapter
  • Linear PCM audio up to 24bit/192kHz and DSD audio up to 5.6MHz playback* requires a DSD playback software on PC such as the upcoming "FOSTEX Audio Player". Both DoP and ASIO acceptable
  • Quick and easy hi-resolution playback in combination with "FOSTEX Audio Player" software
  • HI/LO Gain selection (10dB) for wider range of headphones
  • Asynchronous transfer mode by using the custom made crystal
  • Digital Filer selecting Roll-off characteristics and Cut-off characteristics according to the audio source
  • Complies with USB Audio Class 2.0 on Windows XP (SP2 or later) / Vista / 7 / 8 and MacOS X 10.6 or later. ** ** requires the dedicated driver for Windows. Not compatible with Windows XP 64bit
  • MicroSD (SDHC) card drive on the rear panel for future firmware update.*** does not playback audio data stored on a microSD card