This headphone amplifier allows one audio input to be split to up to four separate volume adjustable headphone outputs. Ideal for recording or performance situations involving one to four people the amplifier can be connected to a mixer output so performers can hear themselves and each other while recording or during playback. Similar applications can be applied to band rehearsals, classroom environments or even home entertainment systems. The unit can be driven via either a 6.3 mm stereo jack or stereo RCA to 6.3 mm adapter (included).