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.

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

MPN: AMS-HP-A4BL

• 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
  
  Input
  
• [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
  
  Output
  
• [PHONES BALANCED] terminal
  
• 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)
  
  [PHONE UNBALANCED] terminal
  
• Connector :1/4" stereo jack
  
• Maximum output :300mW 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
  
  General
  
• [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