The EHX Bass Mono Synth transforms your bass into eleven great sounding synthesizers… from vintage synth emulations to thick, stacked voices to deep pulsing sounds and more. Its intuitive layout makes it easy to use and easy to dial in good sounds quickly. DRY controls the volume of your dry bass signal at the Synth Output. SYNTH controls the volume of the Synthesizer sound at the Synth Output. Used together they let you create just the right mix. The SENS control, short for sensitivity, adjusts how your playing dynamics trigger the synthesizer and allows you to fine tune the way the pedal responds to your bass rig and playing style.