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
William Bryson (electrical engineer) had offices at 16 Queen Charlotte Street in Leith. He died on 9 July 1906. He is buried in Warriston Cemetery. The grave lies on the diagonal path joining the lower vaults to the sealed eastern entrance. The stone is currently (2018) vandalised and is lying on the ground in undergrowth. William Bryson (electrical engineer) William Alexander Bryson FRSE (2 March 1855 – 9 July 1906), was a Scottish electrical engineer. He was born on 2 March 1855, the son of Alexander Bryson and Elizabeth W. Gillespie. His grandfather was Robert Bryson. His mother died shortly after he was born,