The Terrain Deluxe is a Harmonic Tremolo with Tap Tempo, featuring a high fidelity all analog signal path using LightDependent Resistors (LDRs) for modulation. The Harmonic Tremolo mode uses an electronic crossover to split the signal into high and low frequency components.These are modulated 180 degrees out of phase and then re-combined creating a wet, lush tone. Speaking of tone, theTone control pans between the high and low frequency signals, going from full treble to full bass and everything in between. In the unlikely event that you get tired of the beautiful Harmonic Tremolo there is a Normal / Harmonic mode switch. In Normal Mode the high and low components are modulated together creating a traditional tremolo sound.