DSD, short for “Direct Stream Digital”, is the name that was given to ‘PCM audio with just one bit’, as Peter Eastty of Sony Oxford once put it. The format is native to some AD and DA converters, such as the Grimm Audio AD1. The one bit signal has some unconventional features that lead to ‘frequently asked questions’. So Bruno Putzeys and Eelco Grimm decided to write a “DSD FAQ” white paper.