Sample and hold circuits are also frequently found on synthesizers, either as a discrete module or as an integral component. They are used to take periodic samples of an incoming signal, typically as a source of modulation for other components of the synthesizer. When a sample and hold circuit is plugged into a white noise generator the result is a sequence of random values, which - depending on the amplitude of modulation - can be used to provide subtle variations in a signal or wildly varying random tones.[6]