Originally founded in 1919 by Charles Francis Brush Jr. as Brush Labs, a research company based in Cleveland, Ohio, the company was started with the intention to develop phonographic products that utilized piezoelectric crystals. Mr. Brush died prematurely in 1927 but his backers founded the Brush Development Company in 1930 to commercialize the inventions of Brush Labs. The newly formed company became the USA's biggest manufacturer of instrument recorders and other test and measurement instrumentation in the latter half of the 30s. Brush's main business in 1943 was the production of piezoelectric phonograph pickups.
Another of their products was wire recorders. These used ferromagnetic stainless steel wire, with a composition similar to high carbon high chromium cutlery steel as the recording medium. The recording head was a split ring, with the wire running in a groove in the head, quite similar to the heads used today. High frequency AC bias was used to linearize the recording. The ferritic stainless steel was quite strong. Diamond dies were required to draw it into wire.
The Brush Vice President for Research, Dr. Semi Joseph Begun, obtained a contract from the US National Defense Research Council to perform research and development on a substitute for the stainless steel wire. The work was justified by the military use of the recorders and the shortage of facilities for producing the diamond dies. It resulted in the production through work at Battelle Memorial Institute of iron oxide magnetic recording tape of exceptional quality. After the war Brush released the Mail-A-Voice dictation recorder. The Mail-A-Voice was the first magnetic disc recorder. In his book Magnetic Recording, Semi Joseph Begum says "It was used by department stores. Parent bought the equipment and gave a unit to their son or daughter who might be away from home and kept one unit at their own disposal. The powder-coated discs were mailed and served as "spoken" letters. Today's floppy discs for computers are basically an outgrowth of the original discs for correspondence."
in 1946 and the first USA built tape recorder in 1947. For a time in the early 50's the company became the primary supplier of automated tape recorders for businesses such as aviation control and telephone exchanges.
Brush Development Co. merged with the original Brush Labs and the Cleveland Graphite Bronze company in 1952 with the resulting new company named Clevite. Audio products continued being sold using the Brush trademark as late as 1960. The Clevite company exited the audio market altogether in 1963 and was taken over by Gould-National Batteries in 1969.
Go to Article by the Audio Engineering Society • Go to Brush Development Company Stories
Brush reel to reel tape recorders in the Reel2ReelTexas.com vinyage recording collection
This is a very unique Brush BL-301 Vibration Transducer donated to our Museum by Dave Meyers of Overkill Audio, Inc. view pdf
Brush Mail-A-Voice 1946
The model BK-503 Mail-A-Voice from "The Brush Development Company", represents an entirely different approach to the problem of storing information on a magnetic medium. The recording material in this case is in the form of a 9-inch disc, and the sound track is a spiral running from an inner diameter of 5 inches to the outer edge. The recording track has a width of 0.014 inch, and the pitch of the spiral is 0.025 inch. Despite this close spacing, no noticeable crosstalk can be detected. The powder-coated paper discs can be folded and mailed like an ordinary letter. No guide grooves are provided on the coated discs.
After the war Brush released the Mail-A-Voice dictation recorder. The Mail-A-Voice was the first magnetic disc recorder. In his book Magnetic Recording, Semi Joseph Begum says "It was used by department stores. Parents bought the equipment and gave a unit to their son or daughter who might be away from home and kept one unit at their own disposal. The powder-coated discs were mailed and served as "spoken" letters. Today's floppy discs for computers are basically an outgrowth of the original discs for correspondence."
Brush Development Company / Brush Electronincs Company ads
Brush photos contributed by others
Brush BK 313 VRW-1 wire reel to reel recorder - U.S. Navy - photos above provided by Brett Goggin Minot, ME
Brush BK 313 VRW-4wire reel to reel recorder - U.S Navy - photos above provided by Judy Dalton not2bright.com
We appreciate all photos sent to our museum. We hope to successfully preserve the sound recording history. If we have not credited a photo, we do not know its origin if it was not taken by the contributor. Please let us know if a photo on our site belongs to you and is not credited. We will be happy to give you credit, or remove it if you so choose.
Brush Development Soundmirror BK-401
Brush Development Soundmirror BK-414
Brush Development Company Mail-A-Voice