Patent ID: 8467550

Claim:
A condenser microphone, comprising: a condenser microphone unit; a head unit including an FET for converting capacitance changes in the condenser microphone unit into sound signals and an emitter-follower current gain transistor for amplifying the sound signals appearing at source of the FET in a predetermined manner; and a microphone body including a 3-pole output connector to which a phantom power supply is connected and a feed circuit having first and second current regulative diodes fed from the phantom power supply for applying a drive current to drain of the FET, the head unit being connected to the microphone body in an electrically and mechanically removable manner, wherein on the head unit side, the current gain transistor is connected between the drain of the FET and a ground, a drain line connected to the drain of the FET serves as both a feed line and a signal output line, and the drain line has a first connecting terminal to the microphone body, wherein on the microphone body side, the first and second current regulative diodes are connected to a second pin on hot side and a third pin on cold side of the 3-pole output connector, respectively, respective cathode sides of the first and second current regulative diodes are both connected to a second connecting terminal that is a counterpart of the first connecting terminal, a first AC coupling capacitor element is connected between cathode and anode of the first current regulative diode, and a series circuit of a second AC coupling capacitor element and a resistive element is connected between anode of the second current regulative diode and a ground, and wherein when the head unit and the microphone body are connected, connections are made between the first and second connecting terminals and between the grounds.