The AVN-HA1 and AVN-HD1 are headphone amplifiers which can be
combined with AVN-Portal units to provide a headphone distribution
system. The units can be powered via their connection to an AVN-Portal or
alternatively via a DC power connector located on the rear panel of the unit.
On the front panel a 6.35 mm (1/4") headphone socket is available along
with a volume control knob. A Mute button is also provided that controls
a GPO which can trigger an AVN-Portal to perform functions such as muting
an input stream or an output stream. A power status indicator LED is located
on the front panel of the device. This will illuminate red when power is
available. On both units, a loop through audio output is available. This allows
the headphone amplifiers to be daisy chained, or to be quickly and easily
inserted in-line between two other pieces of equipment, allowing monitoring
of the audio feed.

The AVN-HD1 is compatible with the AVN-PD8/D Portal.