Common Synthesizer Effects
Reverberation: Reverb is the persistence of sound in a space after the original sound has been produced. It is caused by a large number of echoes accumulating for reflecting off of surrounding walls and surfaces. The decay of a natural reverb is dependent upon the size of the area in which the original sound is produced. In modern synthesizers, most reverb effects are based on signal processing algorithms. Older analog methods used springs to introduce physical reverb to the output signal by picking up the vibrations produced by a metal spring.
Delay: Delay effects record the input signal onto a storage medium, where the sound is then played back, and slowly decays. Old analog tape delays recorded the input signal onto a tape which is then played back. The tapes would pay back and erase the recorded sounds in real time, which quickly led to wear and tear of the tape. Digital delays record the input signal through an analog to digital converter, where it then undergoes various forms of signal processing and place in the internal storage buffer, where the sound is then played back.
Distortion: A distortion effect is achieved by compressing the peaks of an incoming signal and giving it overtones and harmonics. Distortion naturally increases the gain of the signal due to its compressing characteristics and overtones. However, modern day distortion effects do not achieve distortion through over-driving tube amplifiers, and can produce distorted effects with minimal gain.
Phaser: Phasers create filters that attenuate different frequencies. Multiple filters are often used, and they are typically modulated by another source to sweep through the frequency spectrum, giving the phaser its characteristic sound. The source signal is split into two paths, and one path is treated with an all-pass filter that changes the signals phase. When its one path's phase is the opposite of the other path, the phases cancel out causing a notch in the spectrum. The filter sweeps are generally modulated via low frequency oscillators.
Low Frequency Oscillator: LFOs are a staple of modern synthesizers. They are used purely to modulate other synthesizer parameters, such as effects, filter cutoff, and resonance. LFOs have dedicated frequency modulation knobs, so that the oscillations can be as fast or as low as desired, while keeping in time with the synthesizers internal clock tempo. LFO shapes generally come in any generic waveform such as sine or triangle waves, but they can also have random oscillations.
Delay: Delay effects record the input signal onto a storage medium, where the sound is then played back, and slowly decays. Old analog tape delays recorded the input signal onto a tape which is then played back. The tapes would pay back and erase the recorded sounds in real time, which quickly led to wear and tear of the tape. Digital delays record the input signal through an analog to digital converter, where it then undergoes various forms of signal processing and place in the internal storage buffer, where the sound is then played back.
Distortion: A distortion effect is achieved by compressing the peaks of an incoming signal and giving it overtones and harmonics. Distortion naturally increases the gain of the signal due to its compressing characteristics and overtones. However, modern day distortion effects do not achieve distortion through over-driving tube amplifiers, and can produce distorted effects with minimal gain.
Phaser: Phasers create filters that attenuate different frequencies. Multiple filters are often used, and they are typically modulated by another source to sweep through the frequency spectrum, giving the phaser its characteristic sound. The source signal is split into two paths, and one path is treated with an all-pass filter that changes the signals phase. When its one path's phase is the opposite of the other path, the phases cancel out causing a notch in the spectrum. The filter sweeps are generally modulated via low frequency oscillators.
Low Frequency Oscillator: LFOs are a staple of modern synthesizers. They are used purely to modulate other synthesizer parameters, such as effects, filter cutoff, and resonance. LFOs have dedicated frequency modulation knobs, so that the oscillations can be as fast or as low as desired, while keeping in time with the synthesizers internal clock tempo. LFO shapes generally come in any generic waveform such as sine or triangle waves, but they can also have random oscillations.