Alan Blumlein

Alan Dower Blumlein ( born June 29, 1903 in Hampstead (London), United Kingdom, † June 7, 1942 in London) was a British electrical engineer who many inventions in telecommunications, sound recording in which, in the Stereophonic sound, the record, the TV and made the radar. He received 128 patents.

His path in life seemed at the age of seven years, to have stood firm when he surprised his mother with a bill for repairing the doorbell, which was signed " Alan Blumlein, an electrical engineer ." After he was enrolled at Highgate School in 1921, he studied at the City and Guilds College, was the part of the Imperial College. He received a " Governor's scholarship " and was able to jump into the second year of the course. Two years later he graduated with " first class honors B.Sc. ". On 7 June 1942, he died during an experiment with scattering H2S radar. The Halifax bomber flown by him crashed, all on board died.

The already developed by Alan Blumlein in 1931, but until 1957 marketed by EMI flank writing the stereo record enabled mono compatible stereo recordings. The sound information for the left and right channel is imprinted in the 45 ° flank of the groove. In the inner edge of this, the left channel are stored in the outer groove side and the right channel. The direction of the deflection of the cutting stylus is chosen so that a mono signal, which is recorded with a stereo cutting head that produces a page header. This backward compatibility with mono systems is guaranteed. The significant ultralinear circuit of a tube power amp in tube amplifiers goes to his patent (UK patent number 496.883 ) back in 1938.

Also a classic stereo recording method ( Blumlein stereo microphone and the Blumleinmikrofonverfahren ) has been developed with two crossed eight microphones and an axial angle of 90 ° through this stereo records theory. A coincidence in microphones ( stereo compact microphones ) popular design.