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
Anil K. Jain (electrical engineer, born 1946) entrepreneurs such as Brian Hinman, co-founder of PictureTel, Polycom, and 2Wire. Optivision later, after Jain's untimely death, had an initial public offering primarily thanks to the Optivision optical switching technology. Anil K. Jain (electrical engineer, born 1946) Anil K. Jain (January 21, 1946 – November 14, 1988) was an Indian-American electrical engineer and Professor of the Department of Electrical Engineering and Computer Science at the University of California, Davis, known for his contributions on "two-dimensional stochastic models for images provided a firm theoretical foundation for a number of algorithms of spectral analysis, adaptive image estimation and image data compression", including