Headphone amp
Short for headphone amplifier, a headphone amp is an accessory for increasing the audio volume and quality transmitted from a device like a smartphone or laptop to wired headphones. Two main components achieve this: the amplifier itself and the DAC (digital-to-analog converter). Like any amplifier, a headphone amplifier boosts the amplitude of the audio signal, allowing for a higher volume and the richer sound. While every electronic device with sound output needs a built-in DAC to convert the digital audio to an analog signal, a headphone amp DAC may improve the output from a lower-end computer.
Headphone amps may also double as headphone splitters, allowing several pairs of headphones to listen to the same device's audio. When this is the case, each headphone jack on the amplifier has its own volume knob that can be adjusted separately from the others.
Should I use a headphone amp?
Probably not. Most modern devices have a high-quality DAC included through the headphone jack. In addition, an average pair of mid-range earbuds or headphones are not significantly improved by an amplifier. Because of these reasons, it's usually unnecessary to buy a headphone amp. However, if you're an audiophile and have an expensive pair of headphones that don't quite reach their full capabilities, a headphone amp may help you.
Can a headphone amp be used for speakers?
No. Headphones require a relatively low amount of amplitude compared to speakers, which need to get much louder. Headphone amps are designed for headphones, and therefore don't fill the more demanding requirements of a speaker or set of speakers.
Electronics terms, Headphone jack, Peripheral, Sound terms, Volume knob