Thank you for viewing. This item was purchased new and used approximately 4 or 5 times in a studio, and has been stored since. There is no crackling, and the sound output is perfect. Also, when in use, it was placed on top of an amplifier and kept on constantly, so there was no switching with the foot, and the appearance is in good condition. It has not been transported around in an effects board, either. Because it is germanium, it is a booster with a characteristic lift when the guitar's volume is turned up from 8 to 10, like a Fuzz Face. (It is not a fuzz.) This is a piece of equipment for true professionals, focused on distorting the vacuum tube by manipulating the volume on the guitar. Because it is germanium, it needs to be placed at the beginning of the signal chain. Also, it only uses a 9V battery; an adapter cannot be used. The battery will be removed before shipping to prevent leakage, so the winning bidder will need to provide their own.