A sample-and-hold circuit samples a voltage on a trigger and holds that value until the next trigger

A sample-and-hold (S/H) module takes a snapshot of its input voltage whenever it receives a trigger, then holds that voltage constant at its output until the next trigger arrives. If the input is a noise source, each trigger produces a random voltage — the classic staircase random CV for random-pitched sequences or glitchy modulation. If the input is an LFO, S/H creates a stepped version of the LFO’s wave. S/H is a fundamental building block for generative patches: combined with a sequencer’s clock as the trigger and white noise as input, it produces the archetypal random melody. Adding slew after S/H smooths the steps into gliding random curves.

Examples

Clock trigger into S/H trigger input, white noise into S/H signal input, S/H output into VCO 1V/oct: every clock pulse picks a new random pitch. Same patch but with slew limiter on the output: pitches glide between random values.

Assessment

Explain what you hear when S/H samples a triangle LFO at a fast clock vs. a slow clock. Describe the difference in output between S/H with a noise input vs. S/H with a DC voltage input.