The Z-Vex Sonar™ is a pulsing tremolo pedal that works perfectly with higher gain amps to give you both sine wave and square wave tremolo. Four controls, three switches and two footswitches give you absolute control over every parameter, making this an extremely versatile effect. In addition to the Volume and Speed controls, a Duty knob lets you dial in your perfect ratio of time the effect is “on” and “off” as it goes through its cycle. A Clean/Machine switch selects a clean boost or a substantial layer of overdrive. The Tap footswitch lets you determine the rate of effect while the three-way 1/2/4 toggle divides your tap rate into one, two or four cycles per tap for an otherwise impossible effect rate. The Delta control works with the three way Arrow toggle switch to speed up, or slow down, from your tap tempo rate to your predetermined rate for truly dramatic musical effects. Get a fully controllable sine wave tremolo effect by holding down the Tap button while you adjust the Time and Duty controls for long fade ins and fade outs, and the Delta control for Depth.