The SH-03 is a standard sample and hold module.
The rate knob changes the frequency that the samples are taken.
Sample and hold output.
22 khz to 1 hz
A sample and hold module captures the incoming signal and holds that value until its internal oscillator resets, then it repeats the process.
Wire a noise source into the input socket and wire the output socket into the rack master output. At full left position, the output resembles the original noise source, but when turning the rate knob clockwise, you will hear the noise start to slow down into a random amplitude, but changing at regular intervals.
After you have tried that, run the output of the SH-03 into an oscillator's CV input and modulate pitch.