Oscillator sync: Difference between revisions

'''Oscillator sync''' is a feature in some [[synthesizer]]s with two or more [[oscillator]]s. One oscillator will restart the [[period]] of another oscillator, so that they will have the same [[frequency|base frequency]]. This produces a particular type of sound, rich with [[harmonics]], harsh but musical. The oscillator that resets the other oscillator(s) is called the master, and an oscillator that is reset by another oscillator is called a slave. The [[timbre]] can be altered on the slave oscillator by varying its frequency input. There are two common forms of oscillator sync which appear on synthesizers: ''hard sync'' and ''soft sync''. Soft sync is a term used for a variety of mechanisms.

The master oscillator's pitch is generated by user input (typically the synthesizer's [[keyboard]]). The slave oscillator's pitch may be [[musical tuning|tuned]], or detuned]] from this frequency, or may remain constant. Every time the master oscillator's cycle repeats, the slave is re-triggered, regardless of its position. If the slave is tuned to a lower frequency than the master it will be forced to repeat before it completes an entire cycle, and if it is tuned to a higher frequency it will be forced to repeat partway through a second or third cycle. This technique ensures that the oscillators are technically playing at the same frequency, but the irregular cycle of the slave oscillator often causes unnatural timbres and the impression of [[harmony]].

A variety of synthesis architectures are based on sync, often used in conjunction with [[Amplitudeamplitude modulation]], [[Frequencyfrequency modulation]] or [[Phasephase modulation]]. Such architectures include