It sharpens the sound's contours with an exciter-like effect. This is a secret weapon-like piece of recording equipment, known for being used as a hidden trick by recording engineer Eiji Uchinuma, who would apply it to snare drums. I believe it was the top-of-the-line model in BBE's Sonic Maximizer series. The power cord is not included. It's a standard type, so please use one you already have.