Advent Unit with Dolby Noise Reduction
date: label: date made
content: ca 1972
name: label: maker
content: Advent Corporation
notes: label: Description (Brief)
content: Ray Dolby’s 1965 invention of a system for reducing unwanted noise in magnetic tape recording significantly enhanced sound quality in consumer devices. His circuit design compressed and then expanded the electrical signal, a design he called a “sound compander” for which he received U.S. Patent 3,846,719. At first, Dolby’s compander was sold as an add-on component but by the early 1970s, it became an integral part of the equipment. This Advent model 201 cassette deck features a switch to activate Dolby’s system. The recorder also included a switch that allowed the use of chromium oxide tapes. The CrO2 tapes gave superior performance than ordinary ferrite oxide tapes but the sound properties could change over time. The switch helped the Dolby system compensate.
setName: label: See more items in
content: Work and Industry: Electricity
label: See more items in
content: Communications
label: Exhibition
content: Inventing in America
label: Exhibition Location
content: National Museum of American History
creditLine: label: Credit Line
content: from Dagmar Dolby
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 2014.0318.01
label: catalog number
content: 2014.0318.01
label: accession number
content: 2014.0318
objectType: label: Object Name
content: tape recorder
label: Object Name
content: magnetic recorder
physicalDescription: label: Measurements
content: overall: 5 in x 13 7/8 in x 9 1/2 in; 12.7 cm x 35.2425 cm x 24.13 cm