PLLsyntetisaattorit

PLLsyntetisaattorit, also known as Phase-Locked Loop synthesizers, are electronic musical instruments that generate a wide range of sounds using a voltage-controlled oscillator (VCO) and a phase-locked loop (PLL) circuit. The PLL is a feedback control system that synchronizes the output of a VCO to a stable reference frequency. In the context of synthesizers, this allows for precise control over the pitch of the generated audio signal.

The core of a PLL synthesizer consists of a VCO, a phase detector, a low-pass filter, and a voltage-controlled frequency divider. The phase detector compares the phase of the VCO's output signal with a reference signal. Any phase difference is then filtered by the low-pass filter, and the resulting control voltage is used to adjust the frequency of the VCO. This feedback loop continuously corrects the VCO's frequency to match the reference, thus creating a stable and accurate pitch.

By manipulating the control voltage supplied to the VCO, the synthesizer can produce a variety of musical notes. Furthermore, the characteristics of the sound can be shaped by additional synthesizer components such as voltage-controlled amplifiers (VCAs) for volume control and voltage-controlled filters (VCFs) for timbre modification. PLL synthesizers were particularly popular in the late 20th century and are still found in some modern electronic music production gear, valued for their stability and the unique sonic qualities they can achieve.