The meeting of the LRS on 25th January 2017 was a talk on "How Theo Williamson's Amplifier Changed the Sound of Music" which was given by Prof Joe McGeough (above), a former Professor of Mechanical Engineering at the University of Edinburgh.

Photo courtesy Science Museum, London

The Williamson amplifier refers to a type of valve audio amplifier whose circuit design used the same principles as a design published by Theo Williamson of Edinburgh in 1947. He proposed the standard which became generally accepted as the target figure for high-quality audio power amplifiers - for less than 0.1% total harmonic distortion at full rated power output. The amplifier was one of many achievements by Williamson who failed to gain a degree at Edinburgh University by his inability to pass his Maths-1 exam after four attempts!  Click for Full Report.