The Rotovibe is a chorus/vibrato effect that can simulate rotating speaker sounds popularized by Hendrix and many others This is a very expressive effect, thanks to its built-in real-time control. Choose either Chorus or Vibrato, adjust the intensity of the effect, and then control the effect's speed by rocking the pedal back and forth. A mainstay on Zakk Wylde's pedalboard. Power: Dunlop ECB003 AC Adapter or Single 9 volt battery