Hiss On the Tape

Still sorting through cassette tapes and trying to match tapes with cases. Last month Ray Dolby, the engineer responsible for inventing the Dolby Noise Reduction system that reduced 'hiss' on cassette tapes, passed away. These days the name Dolby is more commonly associated with surround sound systems for movies, but way back when, terms such as Dolby NR, Dolby B and Dolby C were commonplace in the audio equipment market. Along with things such as 'wow and flutter', bias settings, head cleaning kits and azimuth adjustment, noise reduction settings are long consigned to history as digital technologies have come to dominate the consumer audio market.

http://www.bbc.co.uk/news/world-us-canada-24075429