Not sure if the amp utilizes this or not but I think it explains where the digital in Pule width modulation comes from

http://www.embedded.com/story/OEG20010821S0096


M80,VP150,QS8,ERD-1,XPA-2,XPA-5,UMC-10,PS3,XBOX360,Dish VIP622,PB13 Ultra,Panasonic PT-AE3000U