The Tube Zipper Envelope Filter/Distortion Pedal from Electro-Harmonix features a warm sounding Tube Envelope Follower and a rich tube Distortion unit. The Tube Zipper uses two premium 12AX7EH vacuum tubes. The unit features an ENV switch, and a Mode switch that selects Tron/Trill mode. It also features Input Gain, Drive, Sensitivity, Frequency, Resonance and Master Volume knobs. When the Tube Zipper is on, the Power LED will light up. The Status LED lights up when the Tube Zipper effect is engaged, and the Frequency LED gets brighter as the filter's peak frequency rises.
 
Includes Power Supply