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
David Davies (electrical engineer) (IEE) 1996-2001, President of the Royal Academy of Engineering He has subsequently been Chairman of Railway Safety, a non executive director of Lattice plc, a non-executive director of The ERA Foundation, Chairman of the Hazards Forum (2002-2010), and safety advisor to the Board of National Grid plc. The Sir David Davies building at Loughborough University, housing the electrical engineering department, is now named after him. David Davies (electrical engineer) Sir David Evan Naunton Davies , known as Den Davies or David "DEN" Davies, (born 1935) is a British electrical engineer and educator. He was knighted for services to science in