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
Object Name
recording device
tape recorder
date made
ca 1948
Brush Development Company
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
place made
United States: Ohio, Cleveland
ID Number
catalog number
accession number
model number
serial number
model number
Magnetic Recording
See more items in
Work and Industry: Electricity
Magnetic Recording
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
from Maurice Musler
Additional Media

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