How A Sample & Hold Works
Sample & Hold is a synthesis tool that repetitively “samples” an input signal and outputs a held voltage until triggered again. In the image below, the smooth gray line shows a continuous input signal. Each time the module is triggered the current voltage is “sampled” and “held” until the next trigger. The red line shows the stepped output signal:
White noise is typically used as an input source to generate a randomly stepped-CV signal. Random sample & hold pitch mod is often heard in sci-fi movies, most recognizably as the voice of R2-D2 (or for you prog-types, modulating filter cutoff in the intro of the ELP tune, "Karn Evil 9" or the Rush tune, "The Camera Eye")
Sample & Hold Controls
Sample & Hold Out jack- The Sample & Hold control signal output (the Master Panel sections tend to have a backwards-ish bottom-to-top signal flow).
Clock Frequency and LED- The Clock Frequency knob sets the rate of the Sample & Hold, from 0.1 to 40 Hz (with Sync switch off) or from 8 beats up to 1/64th note triplets (Sync switch on). The LED above it flashes at the current clock frequency. The LED flashes at the current clock rate.
Sync- When the Sync switch is in the up position, Mod Generator 2 speed will lock to host tempo when using PS-3300 within DAW software, or to the current tempo in the top menu bar when using the standalone version.
Sample & Hold Input jack- If nothing is plugged into this jack, white noise is used as the sample source - in other words, you don't need to plug a cable in to use the Sample & Hold. If a cable is plugged in, the white noise sample signal will be overridden.
External Clock Input jack- Patching a cable into this jack overrides the Sample & Hold internal clock and disables the Clock Frequency knob.
One nice way to use the Sample & Hold Input jack is to patch in a slow-moving mod generator triangle, ramp, or saw wave, and use the output to modulate oscillator pitch. This creates interesting pseudo-sequencer patches.