I'm selling this because I bought it used but no longer use it. Currently, there is no crackling, and the effects are working properly. I am a novice, so I don't know much about the technical aspects. I will respond to comments as best as I can. Please understand the above before purchasing. A guitar effects pedal with volume adjustment. - Model name: micro amp - Color: White - Input/Output Terminals: 1/4 inch jack - Controls: Volume knob - LED indicator: Yes Thank you for viewing. Manufacturer...MXR