Fostex HP-A4BL DAC Headphone Amplifier

Short description
The HP-A4BL High-Resolution DAC / Balanced Headphone Amplifier from Fostex is a high resolution digital-to-audio converter and balanced headphone amplifier well suited for professional audio engineers, mastering engineers, and audiophiles. The HP-A4BL supports PCM audio up to 24-bit/192 kHz and DSD audio up to 11.2 MHz

Last time this product was added to a cart: 02/25/2020

HP-A4BL D/A Converter & Headphone Amplifier

Product Review

It’s exciting and keeps you listening and not much at this price can do that, so it’s an obvious Best Buy.Read the full review here.

Hifi Critic

Model HP-A4BL, designed being based on the current HP-A4, is an affordable USB DAC & Headphone amp offering balanced connection for headphones that is becoming more popular in the market. In addition to the balanced headphone out, it also complies with DSD Audio up to 11.2MHz.

Fostex USB Audio Driver for Windows (V.2.2.1)
Dedicated USB driver software is necessary to install on PC for Windows. Please be sure to uninstall the old driver software, if any, before installing this new software.
You can download the Windows driver here

Windows and Mac OS Compatibility
We confirmed the compatibility with Windows 7 / 8 / 8.1 / 10 and Mac OSX(10.6 or later).

In Detail

  • Equipped with 4-pin XLR balanced output
  • Newly developed audio-grade capacitor is adopted
  • Highly precise crystal with low phase noise is adopted
  • Playback 24bit/192kHz PCM and 11.2MHz DSD audio
  • High performance DAC (Barrbrown PCM1792A) is equipped
  • Asynchronous transfer up to 192kHz/24bit compatible with USB Audio 2.0
  • HI/LO Gain selection (10dB) for wider selection of headphones
  • Digital Filter selecting Roll-Off characteristics and Cut-off frequencies+


[USB] terminal
Interface :USB 2.0 Hi Speed
Sampling Frequencies :PCM 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, 192kHz DSD 2.8MHz, 5.6MHz, 11.2MHz
Quantization :16bit, 24bit
[Digital In] terninal
Connector :Optical, Square
Format :S/PDIF
Sampling Frequencies :44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, 192kHz
Quantization :16bit, 24bit

Connector :XLR (4-pin)
Maximum output :300mW or more (32 ohm)
Load impedance :16 - 600 ohm
THD :less than 0.04% (at 1kHz)
Frequency Response :20Hz - 80kHz (+-3dB, 32 ohm, 100mW)

Connector :1/4" stereo jack
Maximum output :150mW or more (32 ohm) Applicable load impedance :16 - 600 ohm
THD :less than 0.04% (at 1kHz)
Frequency Response :20Hz - 80kHz (+-3dB, 32 ohm, 100mW)

[OUTPUT] (L,R) terninal (Analog output) Connector :RCA Pin
Reference output level :2Vrms (0 dBFS) Applicable load impedance :less than 10k ohm THD :less than 0.01% (at 1kHz)
Frequency Response: 20Hz-80kHz (+3dB)

[DIGITAL OUT] terminal
Connector :Optical (square)
Format :S/PDF
Frequency Response :44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, 192kHz
Quantaization :16, 24bit

[microSD] card slot (for firmware upgrade only) Format: FAT32
Compatible card: microSD card (SDHC), up to 32GB
Accessories :Rubber foot (x4), USB cable, Manual, AC adapter
Power supply :DC12V
Measurements :150(W) x 34(H) x 157(D)mm including protrusion
Weight:approx. 630g

Document Downloads

The following documents are available to download in Adobe Acrobat format.

    Owners Manual - English, French, German


    Declaration of Conformity

For more document downloads, check the manuals section in Technical Support