Amplifier by their physical placement in the signal chain; a preamplifier may precede other signal processing stages, for example. The first practical electrical device which could amplify was the triode vacuum tube, invented in 1906 by Lee De Forest, which led to the first amplifiers around 1912. Today most amplifiers use transistors. The first practical device that could amplify was the triode vacuum tube, invented in 1906 by Lee De Forest, which led to the first amplifiers around 1912. Vacuum tubes were used in almost all amplifiers until the 1960s–1970s when the transistor, invented in 1947, replaced them. Today, most amplifiers
Arthur Williams (electrical engineer) his work in connection with the American Museum of Safety the King of Spain made him a Knight of the Royal Order of Isabel the Catholic. Arthur Williams (electrical engineer) Arthur Williams (August 14, 1868 – April 14, 1937) was an American electrical engineer, executive at the New York Edison Company, Federal Food Administrator of the City of New York, and first president of The National Association of Corporation Schools in 1913. Williams was born in Norfolk, Virginia in 1868, the son of Rev. Christopher S. and Hannah Sanford (Rogers) Williams. He was educated in the public and private schools