The Nagra IV Tape Recorder

It was once the most celebrated portable tape recorder in the world – and yet few Elektor readers will have heard of it. The Nagra was a professional device, developed for professional transportable applications, whether for broadcast use or picture-synchronised audio recording for film and television.

www.ips.org.uk/faq/index.php?title=Tonader_Power
http://en.wikipedia.org/wiki/Sound_follower