Bass guitar headphone amplifier from amPlug 2 series that is designed specifically for low frequencies, offering a wide-range response. It delivers three modes and features a dramatically improved analogue circuit. It also provides a rhythm function, foldable plug mechanism that rotates 180 degrees and an auto power-off function for improved convenience and ease of use. The pre-amplifier is powered by two AAA batteries (up to 11 hours of operation time, 17 with RHYTHM off), and provides a headphone output and an aux input. AAA alkaline batteries are included.