An effects processor, also known as a signal processor, is an electronic device or software used to modify or enhance audio signals. It is typically used in audio production, recording, and live performance settings.

Effects processors can be used to add various types of audio effects to a sound source, such as reverb, delay, chorus, flanger, phaser, distortion, and many others. These effects can be applied to a single audio channel or multiple channels and can be adjusted in real-time using various controls on the device or software.

Effects processors can be hardware devices or software plugins that run on a computer. They can be used in a wide range of applications, from guitar pedals and studio processors to digital audio workstations and live sound systems.