Zuul Blackout's threshold knob also controls the dynamics of the gate circuit. High-quality studio specifications make it ideal for guitars, basses, and any signal source. Can be used before an amp or in a series effects loop. Dual color LED provides visual feedback of gate operation: Green = Open, Orange = Closed, Off = Bypass. The KEY input signal can be taken directly from a guitar (such as a split from a Roach or Spliff) or other signal source, and can be switched from clean to high gain without adjusting the threshold knob. This powerful feature allows you to control the gate with a signal different from the input/output signal. This pedal is packed with features, all working together to allow you to precisely cut the signal to suit your playing style. ■Control BYPASS: True bypass footswitch GATE: Opens the noise gate and adjusts the level required to allow signal through. KEY IN: Applies to 3CM and 4CM only. By plugging your guitar directly into this jack, Zuul can be triggered directly from your guitar, unaffected by any boost or dirt pedals you may have installed. Zuul will function fine as a gate without using the Key Input 2CM (cable method), but for best response we recommend using the Key In via 3CM (with Roach of Spliff) or 4CM. SIDE SWITCH: Changes the threshold (lowering it a little will make the gate work earlier). ZUUL IN: To amp effects (3CM, 4CM) / Instrument in (2CM) ZUUL OUT: Time-based effects (3CM and 4CM modulation, reverb, delay, etc.) / Output to the next unit in the chain (2CM).Power: DC 9-12V center pin negative external adapter/power supply only. Power consumption: 40mA Pedal dimensions (W/D/H): 3.6 x 1.5 x 1.2 (92.5mm x 38.5mm x 30.99mm) Weight: 250g * Always use the center negative polarity of the separately sold power supply.