This is the regular plug in. I have no hissing noise when playing music when running of of battery power, but once I plug the computer into ac power then the hissing starts. Here are the components of my system, Peavey PV8 Mixer Board, Peavey PV115 Speakers, Peavey PV 1500 amp, DBX DriveRack PA Control System, furman PM-Pro II Power Conditioner and a Dell Laptop. All of the pieces are new. The best that I can tell is that the hissing noise is caused by the ac power/charger for the laptop. I am going to try a ground loop isolator to see if this will help. I just bought one off of EBAY and will try it when it arrives.