Circuit structure for suppressing low frequency interference voltages in microphones, e.g. pop or wind noise, feeds microphone voltage to a voltage current current transformer

摘要

A microphone voltage (1) is fed either directly or via an input circuit to a voltage current transformer (VCT) (5) with high dynamic range, preferably 150 - 155 dB. The output current from the VCT flows into the input of a current amplifier (6) which provides an output to an inductor (7) acting as a filter by shunting low-frequency signals to ground. Higher audio signal frequencies are relatively unaffected by the high-pass filtering action and are developed across a load resistor (4).