modulation – Synthesizer Online

Control Voltages (CV)

Control voltages (CV) in modular synthesizers are electrical signals used to control various parameters of the modules, such as pitch, frequency, and amplitude. They are used to control the sound in a similar way to how notes on a keyboard or knob movements on a traditional synthesizer control sound.

CV signals are typically low-frequency signals, usually in the range of 0-5V, and are typically generated by a control voltage source, such as an LFO or an envelope generator. These signals are then sent to various modules via patch cables, where they are used to control different parameters, such as the frequency of an oscillator or the cutoff of a filter.

CV is a standard feature in modular synthesizers and it allows for greater flexibility and expression than traditional synthesizers. CV signals can be used to control multiple parameters at once, and the signal can be modulated by other modules, allowing for complex and dynamic sound creation.

In summary, Control voltages (CV) in modular synthesizers are electrical signals used to control various parameters of the modules, such as pitch, frequency, and amplitude. They are low-frequency signals usually in the range of 0-5V, generated by a control voltage source and sent to various modules via patch cables, allowing for greater flexibility and expression than traditional synthesizers.

Modulation

In a synthesizer, modulation refers to using one signal to control or change another signal. To do this, a signal called the modulator can be routed to control a signal called the carrier’s parameter. An LFO or an envelope generator, which generates a control signal that can be used to modulate different sound parameters, serves as the modulator in most cases.

In synthesizers, the following modulation types are most frequently used:

Amplitude modulation: This involves using an LFO or envelope generator to modulate a sound’s amplitude (i.e., the loudness). This can create effects like tremolo (a modulation of the amplitude at a low frequency) or envelope-controlled volume changes.
Frequency modulation (FM): This involves using one oscillator (the modulator) to modulate the frequency of another oscillator (the carrier). This creates complex, harmonically rich timbres and can create a wide range of sounds, from bell-like tones to metallic and percussive sounds.
Phase modulation (PM): This is similar to FM, but instead of modulating the frequency of the carrier, it modulates its phase. The result is a more subtle, detuned effect that can create chorus, flanger, and phaser effects.
Pulse width modulation (PWM): This involves modulating the width of the pulse waveform of an oscillator. This creates a variation in the harmonic content of the sound and can be used to create a wide range of timbres.
Filter modulation: This involves modulating the cutoff frequency of a filter to create effects like filter sweep and envelope-controlled filtering.

These are only a few applications for modulation in the shaping and sculpting of synthesizer sounds. Modulation is a primary factor that makes synthesizers such potent and versatile instruments, and the possibilities are essentially endless.