With the Boss CS-3 Compression Sustainer you get smooth sustain, a more balanced string response, and more clarity and punch at any volume. A must for recording. Ideal alone for a clean sound or in front of a distortion or chorus.  Compresses louder signals while boosting lower signals for smooth sustain without degrading the original sound quality. Onboard EQ for precise tonal control and low-noise design for super-quiet operation.