Early history of the M49

by Sean Davies
(Aylesbury, UK)

At the end of World War II George Neumann decided that magnetic recording would oust the disc from the market, so he decided to concentrate his firm's production onto microphones. The first post war mic was the U47, which utilised a radio tube, the VF14; this allowed the power supply to feed just one voltage to the mic, the tuba heating being obtained by a dropper resistor in the mic.

In those days any product intended for broadcasting use had to conform to the " Brown Book", a publication which laid down the spec for all parts of the broadcasting chain.

Unfortunately, the use of the VF tube did not match the Brown book requirement, which stated that the tube in a condenser mic had to have a low voltage heater.

An engineer at the radio station Nordeutsche Rundfunk one Grosskopf, felt that the capsule used in the U47 could also be used in a neater case and so he designed a mic. which also had a low voltage heated tube, initially the MSC2 a special purpose tube made by the German firm Hiller.

The first M49's were made by different companies; a late colleague if mine, Herr Klaus Dieter in Munich had a BM49 which had the "B" because it was made in the British zone of Germany just after the war's end. This specimen was slightly longer than Neumann's version.

When Neumann began their version it also used the MSC2, but this was replaced by Telefunken's AC701.

Sean Davies