The HPA4 from Alto is a professional-quality headphone amplifier that provides 4 independent stereo channels in a convenient 1RU rack size. Ideal for use in studio or live sound applications, the HPA4 has 4 independent input/mix sections, allowing you to create 4 different stereo mixes.
Each channel features 3 headphone outputs (1 front, 2 rear), allowing you to connect a total of 12 listeners directly to the amplifier. Each channel has its own output level control and stereo AUX in for connecting an additional signal source. Main I/O is via 3-pin XLR connectors, and headphone connections are made via stereo 1/4" connectors.
Other useful features of the HPA4 include individual treble and bass controls on each channel, as well as mono and mute L/R controls for each channel. LED meters are provided for monitoring both input and output levels.