I bought this system not knowing anything about it except that it said Marantz. The features and availbility to expand this unit are amazing. Easy to work and easy to set up it will accomodate anything from your basic analog system to your HDTV digital or fiber inputs. Multi function selections allow you to listen to different music in different rooms. The only downside is that speaker B can only accept digital or analog whereas the other selections can accept both and auto detect the input.