Improved Clarity,One-Knob Control High-Quality Effects Improved Clarity NUX Stageman Floor is an analog acoustic preamp with digital effects and looper function. Preamp featured with a highly sensitive 3-band EQ with MID scoop toggle switch, adjustable notch filter, and input gain control. And it provides a ginormous headroom which delivers the sound all natural. One-Knob Control High-Quality Effects It equipped with Reverb and Chorus effects and, each effect designed to control by only one-knob, when you tweak the chorus or reverb knob from 0 to 10 it adjusts multiple parameters with a perfect balance. And the chorus switch is a momentary footswitch, while you push and hold, it will activate the freeze effect until you release it. Notch Filter You can turn ON the notch filter and adjust the frequency to clean the notch sound caused by a guitar pick or nails.