Reel-to-Reel Tape Recorder

Description (Brief)
This reel-to-reel BK-401 “Soundmirror” used paper recording tape coated with artificial magnetite particles. Brush Company designed the BK-401 after Semi Begun’s experiments convinced him that a thin, flexible tape would give good audio performance. Introduced in 1947 with tape made by Shellmar Company, the expensive BK-401 malfunctioned easily. Despite good initial sales, production ceased in 1952.
Before leaving Nazi Germany in 1935, Begun had heard of Fritz Pfleumer’s work on printing cigarette paper with a gold-colored band. Pfleumer also made paper tape coated with magnetizable materials and fabricated a demonstration tape recorder in 1931.
Currently not on view
date made
ca 1948
Brush Development Company
place made
United States: Ohio, Cleveland
Physical Description
wood (overall material)
metal (overall material)
plastic (overall material)
glass (overall material)
cloth (overall material)
recorder closed: 12 in x 18 in x 14 in; 30.48 cm x 45.72 cm x 35.56 cm
microphone: 22 cm x 13 cm; 8 21/32 in x 5 1/8 in
ID Number
catalog number
accession number
model number
serial number
model number
Credit Line
from Maurice Musler
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Work and Industry: Electricity
Magnetic Recording
Data Source
National Museum of American History