An Amplifier (ǽmpləfɑ̀yər), sometimes referred to simply as an “amp,” is a device that increases the audio signal made by a guitar. A high quality amplifier is judged by its fidelity, which means the clarity of sound it maintains. Technically, the perfect amplifier will boost the sound wave output of the guitar while keeping it’s original signal’s shape. The better the amp, the better it will increase guitars output while maintaining the correct signal shape. No amplifier will boost a signal with zero distortion, but there is a certain level of distortion the human ear can’t hear, which is the “sweet spot” high-end amp manufacturers aim for.