Audio power amplifier inside the chassis of the main product. The audio amplifier was invented around 1912 by Lee De Forest, made possible by his invention of the first practical amplifying electrical component, the triode vacuum tube (or "valve" in British English) in 1907. The triode was a three terminal device with a control grid that can modulate the flow of electrons from the filament to the plate. The triode vacuum amplifier was used to make the first AM radio. Early audio power amplifiers were based on vacuum tubes and some of these achieved notably high audio quality (e.g., the Williamson amplifier of
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