The Monumental Stereo Harmonic Tremolo is a stereo tremolo pedal designed for electric guitar and other instruments. It is based on harmonic tremolo circuits found in vintage amplifiers. The pedal splits the signal into separate frequency bands that are modulated out of phase. This creates a pulsating effect that differs from standard volume tremolo. The stereo operation allows the modulation to be spread across two outputs. The pedal is intended for live performance and studio use.