What is a headphone amplifier?
A headphone amplifier, or headphone amp, is simply a small amplifier specifically designed to drive the miniature audio drivers inside headphones. Because headphones are often used in portable applications, many headphone amps are conveniently battery powered. Headphone amps can also be used in a work station or desktop setting where they sometimes act as a switch between various sound sources or as a pre-amp for powered desktop speakers. Dedicated headphone amps may also include USB connections for direct power use. Other dedicated headphone amps may use AC/DC power supplies as well.
