Run the microphone into a saturation device. Remove the microphone plug from the PA system. Plug it into the "In" connector on the effects box. Plug the extra connecting cord into the PA system. Turn on the PA and microphone.
Adjust the volume on the PA. Turn on the saturation effect. Electric guitar-type effects boxes are often called "stomp boxes," because they are turned on by pressing down on the pedal with your foot. If the saturation effect is on a rack-type system, turn on the rack system's power button.
Mix the saturation level. On most effects "stomp boxes," such as those from Boss and Ibanez, there are three control knobs: tone, level and drive. Tone knobs adjust the treble, while the level knob adjusts volume. The drive knob controls the amount of saturation produced. Adjust these levels to your liking, the amount of saturation ranges from mild to an old transistor radio cranked all the way.