Green Zapper Auto Filter

The Henretta Engineering Green Zapper Auto Filter is a compact envelope filter pedal designed to add movement and dynamics to the sound of an electric guitar. The pedal utilizes a band-pass filter that sweeps through a frequency range as the user plays. The initial attack of the playing pushes the filter up into high frequencies, then it sweeps back down to low frequencies as the notes decay. The pedal is designed to be attack-sensitive, providing a dynamic response to the player's input.

The Green Zapper is housed in a tiny 2”x2” enclosure, making it suitable for any pedal board. It features a footswitch for turning the pedal on and off, with an LED indicator to show when the circuit is active. The pedal operates on a standard 9-volt (10mA) power supply with a center-negative barrel connector.

Internal trimmers are provided to adjust the range and sensitivity of the effect. These trimmers have been factory set for optimum performance with typical passive single-coil pickups.

The circuit of the Green Zapper utilizes a TL082 dual op-amp, which is positioned in a socket to allow swapping with other op-amps for sonic experimentation. It is important to only swap with op-amps that have the same pin configuration as the TL082.

The pedal is designed to be highly reactive to playing dynamics, and small adjustments to the sensitivity control can have a significant impact on the effect. Users are advised to use their ears to sweep through the trimmer ranges for optimal adjustment.

The Green Zapper is known for its compact size, attack-sensitive auto EQ filter, and its ability to provide a wide range of expressive envelope filter effects for electric guitar players.