Patent ID: 8873777

Claim:
A variable directivity condenser microphone in which a first diaphragm and a second diaphragm are arranged on opposite sides of a fixed electrode to provide two microphone units and directivity is varied by varying a polarization voltage applied to one of said microphone units with respect to a polarization voltage applied to the other microphone unit, wherein a microphone body is provided with a vacuum tube for impedance converting an audio signal obtained at said fixed electrode and a connector having a hot side connector terminal and a cold side connector terminal through which an audio signal that is impedance converted by said vacuum tube is outputted in parallel, a means for supplying a polarization voltage applied to one of said microphone from an external power supply circuit is arranged by using said hot side connector terminal and cold side connector terminal as a forward conductor, and a ground connector terminal of the microphone body arranged at said connector is used as a return conductor.