I recently purchased this on Mercari. No crackling or noise. I'm selling it because I urgently bought an amp that can apply effects through an app. Please understand that this is a used item before purchasing. The Compression Sustainer CS-3 is an effects pedal that allows you to adjust level, tone, and sustain. - Model: CS-3 - Color: Blue - Function: Compression Sustainer - Control Knobs: Level, Tone, Sustain - Connections: Input, Output - Check Lamp: Yes Thank you for viewing.