The LD Systems HPA 1 is a versatile headphone amplifier with high power output for stage, studio and home recording and is the perfect solution for wired in-ear-monitoring.. The compact device in a rugged, ergonomically shaped plastic housing with soft-touch surface and practical belt clip is very extensively equipped.

In addition to locking XLR connectors for the stereo signal L/R input, the HPA 1 has a balanced 3.5 mm stereo jack as AUX input, which can be used in parallel for clicks or playback. It is protected for safe operation against excessive input levels; a hollow pin socket with negative internal contact enables the connection of a network adapter for fixed operation.

A 3.5 mm stereo jack is provided as earphone and headphone output. Volume level and balance can be set with easy-grip knobs, a push-button switches between the summed mono and stereo signals. A full-fledged limiter is integrated for distortion-free playback and as protection against feedback.

The LD Systems HPA 1 has bi-colour LEDs to facilitate the features overview, which displays the response of the limiter during peaks and the battery status. At 165 grams, the headphone amplifier is distinctly light-weight and can be operated for up to 12 hours thanks to a high quality 9 V block battery.

• Model Name: LDHPA1
• Product Type: headphone amplifier
• Type: 1-channel stereo
• Inputs: Main Input (Stereo), 1 x Aux In (Stereo)
• Input Connections: XLR-F (L + R Input, balanced), 3.5 mm stereo jack (Aux In)
• Input Impedance: 6 kOhm (XLR In), 10 kOhm (3.5 mm jack)
• Input Sensitivity: 3 dBu (XLR In), -6 dBV (3.5 mm jack)
• Max. Input Level: 16 dBu (XLR In), 7 dBV (3.5 mm jack)
• Protection Circuits: Audio Limiter, Max. Input leveling, Power OFF -Mute relay
• Headphone Outputs: 1
• Headphone Output Connectors: 3.5 mm stereo jack
• Power Output: 2 x 1.65 Vrms / 1% THD @ 33 Ohm Load
• Minimal Connected Impedance per Channel: 16 ohms
• Frequency Response: 20 Hz - 40,000 Hz
• THD @ 1 kHz Sine: 0.04%
• Controls: Power/Volume, Balance L/R, Stereo/Mono (Focus) switch,
• Indicators: Signal (Green) / Peak (Amber), Battery (low battery: red) / Power LED (Power ON: green)
• Power Supply: 9 V DC block battery, DC jack
• Operating Voltage: 9 V DC
• Power Consumption: Nom. 70 mA / Max. 150 mA
• Housing Material: plastic
• Housing Surface: soft-touch
• Housing Colour: black
• Width: 80 mm
• Height: 42.5 mm
• Depth: 133 mm
• Accessories (included): belt clip