What is a Headphone Amp?

A headphone amp is a gadget, most often used by guitarists, that minimizes the sound coming from the guitar by transmitting it through headphones. About the size of a pack of cigarettes, the small amp allows the guitar player to play as loud as desired because all the sound is projected through headphone speakers, so only the person wearing the headphones can hear the sound. Sometimes called a headphone amplifier, the headphone amp allows the guitarist to practice anytime, night or day, without disturbing friends, family, roommates, or neighbors.

Aside from simple amplification of the guitar signal, a headphone amp can also be a miniaturized portable studio with effects processor, amp modeling, and rhythm machine. Analog and digital effects processors can emulate everything from heavy distortion to hard-core crunch, chorus, echo, funk, and more and it is possible to listen to how different the effects sound through a variety of digital amps — from the Classic Fender tube amp of the 60s, to Marshal, Vox, and others.

A built-in rhythm machine can provide several different rhythm patterns to serve as a drummer; then, with the press of a button, the headphone amplifier allows the guitarist to select a venue, at which point the amplifier can place the drums, guitar, and chosen amp in a club, large arena, or other acoustic environment, which changes the overall sound of the music. A headphone amplifier that does not include a drum machine often includes a click track metronome or sampled snare drum kit to provide a backbeat, and beats-per-minute or tempo is usually adjustable, which can be helpful when working on rhythm and timing.

One of the nicest features of a headphone amp is the ability to learn new songs by using the auxiliary line in to include sound from a radio, CD, or MP3 player. Often, a guitarist needs to play along with a song to learn how to play it correctly; if this needs to be done quietly, then the option of playing all sound through headphones can be beneficial. Other options for using headphone amps while learning to play new songs include downloading tabs from the Internet and working out each measure while listening to the song through the headphones. Some guitar players prefer learning the song on their own, so some headphone amplifiers include a feature that records up to 30 seconds of a song, then slows it down to one quarter of the original speed without changing the pitch, and plays it back in steps.

Another handy feature included with most models is a built-in, digital guitar tuner. LED lights indicate flat, sharp, or true tuning for each note. Some models are also designed with a protruding jack that slides right into the guitar itself, eliminating the need for a guitar cord to connect the tuner to the guitar. Digital tuners can be more accurate that tuning to a piano as a piano can be out of pitch if it has not been properly or recently tuned.

The price of a headphone amp can vary, depending on the model, and they are usually available everywhere guitars are sold. One manufacturer has combined a 4-track digital recorder with headphone amp, creating a palmtop recording studio that includes programmable bass and drum machines. In most cases, bass guitars have their own designated models.