I purchased this used and incorporated it into a pedalboard, using it several times. However, I'm selling it because I've replaced the board. Currently, there's no crackling, and the effects are working correctly. I'm 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. BOSS DD-3 Digital Delay, capable of echo, feedback, and level adjustments, with signs of use. - Model Name: DD-3 - Type: Digital Delay - Output Terminals: OUTPUT, DIRECT OUT - Input Terminals: INPUT - Controls: Echo, Feedback, Level - Color: White - Condition: Shows signs of use, has scratches Thank you for looking. Manufacturer...BOSS