A synthesiser effect pedal transforms a guitar’s signal into synth-like tones by generating or modifying waveforms using oscillators, filters, and modulation. Unlike traditional distortion or modulation effects, synth pedals create entirely new sounds, often mimicking analogue or digital synthesisers. Some pedals track the pitch of the guitar and generate square, saw, or sine waves, while others apply envelope filtering, resonance, or sample-based synthesis to reshape the tone. Synth effects can produce deep bass drones, laser-like leads, or glitchy, robotic textures. Popular synth pedals include the Electro-Harmonix Synth9, Boss SY-1, and Meris Enzo, offering guitarists a way to explore electronic and experimental sounds without needing a keyboard.