Nobels CH-D Stereo Digital Chorus Impressive broad and swirling sounds. The digital design creates a better frequency range and less noise than conventional analog devices. Controls: Intensity, Speed, Resonance, Effect Level, 4 pos. Time Switch Features: Input for remote switch, heavy metalhousing, fast/easy battery exchange Power: 9V battery or electr. stabilized power supply 9V..12V DC, min. 100 mA, 2.1mm plug, tip neg. (Not included.).