Ideal for monitoring with bands and artists. The PreSonus HP4 4 Channel Distribution Amplifier is a compact headphone amp designed for live and studio use. The PreSonus HP4 is the perfect companion for any studio engineer or band. It is perfect for use with PreSonus? other interfaces such as TubePre Comp16 and EQ3B. Each of the four channels features its own dedicated volume potentiometer. Each headphone output provides 130mW per channel providing more than enough volume for even the most demanding player. It also includes a mono summing switch for each channel as well as a monitor mute switch. The HP4 provides the ability to daisy-chain multiple units via the monitor outputs for added flexibility. Ideal For Bands and Ensembles The HP4 from PreSonus is a 4-channel headphone amplifier. The streamlined design makes it ideal for studio work and live rehearsals allowing you to practise quietly. The four-channel design feature 4 high-powered stereo 1/4-inch headphone outputs. Each output features its own dedicated volume control. It also includes 2two balanced 1/4-inch line outputs (monitor outputs and two balanced 1/4-inch line inputs. A mono summing switch is available for each channel as well as including a monitor mute switch. This gives you the ability to easily kill the sound should you need to talk to your band/artists. You can even daisy-chain multiple units via the monitor outputs for added flexibility. High-Volume Headphone Outputs Each of the four headphone outputs provides 130 mW per channel for intensely high volume levels for even the most demanding artist. The premium-grade circuitry delivers an extremely wide dynamic range. This results in pristine sound that captures every nuance of your source audio. Compact Portable and Robust The simple yet sleek design delivers a simple and effective way to process your headphone channels. The concise controls give you the ability to mute the rear-panel Monitor outputs whilst leaving the headphones outputs active. The compact yet robust construction is ideal for use on a desktop. It can also be screw-mounted to a standard rack tray utilising only 1/3 of a rackspace. The high-grade components are sealed and detented with metal rotary controls that will withstand the rigors of extensive day to day use. The unit comes complete with an external 16 VAC power supply. Features Input/Output 4 screaming-loud (130 mW per channel) stereo 1/4″ headphone outputs (front panel) 2 balanced 1/4″ line outputs (monitor outputs) 2 balanced 1/4″ 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 Specifications Inputs Connector Type: XLR- 1/4″ TS Combo balanced THD+N: 0.0025 1 kHz unity gain Max Input Level: +18 dBu Input Impedance: 10k Ohms Frequency Response: 20 Hz – 20 kHz +0.5dB Monitor Outputs Connector Type: 1/4″ TRS asymmetrical impedance-balanced THD+N: 0.0025 1 kHz unity gain Max Output Level: +18 dBu Output Impedance: 51 Ohms Frequency Response: 20 Hz – 20 kHz +0.5dB Headphone Outputs Connector Type: 1/4″ TRS stereo Max Output Power: 130 mW/Ch Frequency Response: 20 Hz – 20 kHz +0.5 dB 60 load Headphone Impedance Working Range: 32 Ohms – 600 Ohms 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) Weight: 5 lbs (2.27 kg)