The HPAJr Headphone Amplifier is a
compact, battery / external dc powered unit designed to
interface your favorite full-sized professional headphone to a
variety of audio input sources. Now you won't be limited to
small, poor quality "in-ear" or "walkman" type headphones for
your monitoring or listening needs. The HPAJr will allow you to
drive headphones of many impedances to more than adequate
listening levels with a full, rich sound not obtainable at low
output levels or with lightweight "personal" earpiece /
headphones. You can use the HPAJr for such professional purposes
as increasing monitor levels from: mixers, portable VCR's, tape
recorders or R-DAT's; personal listening to keyboards and
synthesizers or monitoring of home studio gear. Compact and
durable, the HPAJr comes with a sturdy belt clip for complete
portability.