#Oscillatorsync
is a feature in some synthesizers with two or more VCOs, DCOs, or "virtual" oscillators. As one oscillator finishes a cycle, it resets the period of another oscillator, forcing the latter to have the same base frequency. This can produce a harmonically rich sound, the timbre of which can be altered by varying the synced oscillator's frequency. A synced oscillator that resets other oscillator(s) is called the master; the oscillators which it resets are called slaves. There are two common forms of oscillator sync which appear on synthesizers: Hard Sync and Soft Sync. According to Sound on Sound journalist Gordon Reid, oscillator sync is the least understood feature for many users of a synthesizer.[1] Hard Sync The master oscillator's pitch is generated by user input (typically the synthesizer's keyboard), and is arbitrary.
The slave oscillator's pitch may be tuned to (or detuned from) this frequency, or may remain constant. Every time the master oscillator's cycle repeats, the slave is retriggered, 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 complex timbres and the impression of harmony. If the tuning of the slave oscillator is swept, one may discern a harmonic sequence[2].
This effect may be achieved by measuring the zero axis crossings of the master oscillator and retriggering the slave oscillator after every other crossing. This form of oscillator sync is more common than soft sync, but is prone to generating aliasing in naive digital implementations. Soft Sync There are several other kinds of sync which may also be called Soft Sync. In a Hard Sync setup, the slave oscillator is forced to reset to some level and phase (for example, zero) with every cycle of the master regardless of position or direction of the slave waveform, which often generates asymmetrical shapes. In some cases,[3][4] Soft Sync refers to a process intended to nudge and lock the slave oscillator into the same or an integer or fractional multiple of the master oscillator frequency when they both have similar phases, similar to a phase-locked loop.
In electronics, ring modulation is a signal processing function, an implementation of frequency mixing, performed by creating multiple frequencies from those of the two signals, where one is typically a sine wave or another simple waveform and the other is the signal to be modulated. A ring modulator is an electronic device for ring modulation. A ring modulator may be used in music synthesizers and as an effects unit. weki
