Blumlein

Alan Dower Blumlein (1903-1942) was an electronics engineer who was instrumental in the development of stereo recording techniques and equipment in the 1930s when working for EMI. His inventions include the equalateral speaker triangle arrangement, coincident microphone arrays, shuffling, the 45/45 record groove format and cutting head, the Mid-Side format and matrixing. He also designed several high-quality moving-coil microphones, and conceived the concept of the Jecklin Disc. Amongst his many other inventions, were several fundamental building blocks for television sets (flyback scanning, black-level clamping, slot-antennas), as well as the 'Long-tailed Pair' topology for a differential amplifier, and RADAR. In his early work with STC he was involved in measuring the human hearing response and developed the first measuremetn weighting networks.