PC4uMusic configuration is always an individual order . It can be comprehensively, as in the American Marantz constructions or only what is necessary, as in the British-Norwegian NAD traditions. Can be elegant like the B&O sound system from Denmark and drive as safely as the ReVox tape recorder from Switzerland. AmpDoc PC is a good name for the work of a psychoacoustic laboratory where this project is carried out At the event in AmberExpo we invited artists to collaborate with us on creating new PC visions for music playback. The concept without a housing was created with the Swedish artist Per Dahlberg and was at the center of the stand. The American Marantz had in the 1970s an impressive quadraphonic offer "his is one of the more powerful Marantz receivers ever made. It’s the Marantz 2500. It is somewhat rare and was produced from 1977 to 1979. It retailed for around $1600.00 and was eventually replaced by the 2600. The 2500 put out 250 watts per chann