An LFO (Low Frequency Oscillator) is a type of oscillator that generates a repeating waveform with a frequency that is below the range of human hearing, typically less than 20 Hz. LFOs are used to modulate various parameters of a modular synthesizer, such as the frequency or amplitude of an oscillator, the cutoff frequency of a filter, or the rate of an envelope.
The waveform generated by an LFO can take a variety of shapes, including sine, triangle, sawtooth, and square waves. Each waveform has a unique harmonic content and can be used to create different modulation effects. For example, a sine wave LFO can create smooth and gradual modulation, while a square wave LFO can create abrupt and rhythmic modulation.
LFOs can be synchronized to the tempo of a musical composition or left to run freely, creating evolving and unpredictable modulation effects. LFOs can also be modulated themselves, creating more complex and dynamic modulation effects. For example, an LFO can be modulated by another LFO or by an envelope, creating modulation that changes over time in a more intricate and evolving way.
LFOs are a versatile and essential component of modular synthesis, allowing users to create dynamic and evolving modulation effects that add depth, movement, and interest to their sounds.