Had enough of straining to hear audio from underpowered headphone mixes? Here's your solution. The PreSonus HP4 answers the project studio owner’s need for quality, professional-grade headphone distribution with superb specifications, and all in a compact, affordable, simple-to-use package. It accepts unbalanced ¼" inputs, and delivers ¼" TRS out. Its input can be stereo or mono (a mono input sends copies to both outs), it features 4 front panel headphone outs with volume control, -98 dB noise floor, monitor MUTE, and is powered by an external wall-mounted power supply.

PreSonus HP4 Features:

• Four High Power Headphone Outputs
• Ultra loud (150mW per channel)
• Ultra quiet operation
• Musical Wide Dynamic Range
• Control Room Monitor Outputs with Level Control
• Mono or Stereo Operation
• Monitor Mute Switch
• Daisy Chain an Infinite Number of Units (additional units sold separately) 
• Compact 1/3U rack-mountable package

PreSonus HP4 Specifications:

• Number of Channels: 1 in, 5 out
• Dynamic Range: >115 dB
• Signal to Noise Ratio: >95 dB
• Headroom: +22 dBu
• Frequency Response: 10 Hz to 50 kHz
• Input Impedance: 10 kOhms
• Master Output Impedance: 51 Ohms
• THD + Noise: <0.002%
• Internal Operating Level: +0 dBu = 0 dB
• Headphone Output Power: 150 mW
• Input Connectors: ¼" TRS
• Master Output Connectors: ¼" TRS
• Power Supply: External, Linear Supply
• Power Requirements: 16 VAC, 1000mA, 20 Watts
• Dimensions: 5.5" x 5.5" x 1.75"
• Weight: 4 lbs.