Presonus HP4 HP4 HP-4 Headphone Amplifier

Input/Output
4 screaming-loud (130 mW per channel) stereo ¼” headphone outputs (front panel)
2 balanced ¼” line outputs (monitor outputs)
2 balanced ¼” line inputs
Meters, Controls, and Features
Headphone level control for each channel
Mono summing switch for each channel
Monitor level control
Monitor mute switch
Daisy-chain multiple units via monitor outputs
Physical
Compact 1/3U rack-mount chassis
Sealed, detented, metal rotary controls
External 16 VAC power supply
Technical Specifications
Inputs
Connector Type ¼” TRS, balanced
THD+N 0.0025%, 1 kHz, unity gain
Max Input Level +18 dBu, <0.5% THD+N, unity gain
Input Impedance 10 kΩ
Frequency Response 20 Hz - 20 kHz, ±0.5dB
Monitor Outputs
Connector Type ¼” TRS, asymmetrical, impedance-balanced
THD+N 0.0025%, 1 kHz, unity gain
Max Output Level +18 dBu, <0.5% THD+N
Output Impedance 51Ω
Frequency Response 20 Hz - 20 kHz, ±0.5dB
Headphone Outputs
Connector Type ¼” TRS, stereo
Max Output Power 130 mW/Ch., <0.5% THD+N, 60Ω load
Frequency Response 20 Hz - 20 kHz, ±0.5 dB, 60Ω load
Headphone Impedance Working Range 32Ω - 600Ω
Power
External Adapter Type +12 VDC, 1000 mA, center pin positive
Physical
Dimensions 1/3U rack-mount (with standard rack tray, not included)
Height 1.75” (44.45 mm)
Depth 5.5" (139.7 mm)
Width 5.5” (139.7 mm)