| 摘要 |
PROBLEM TO BE SOLVED: To obtain a clear output by housing a microphone, an amplifier and a filter to suppress a low frequency component of an amplified microphone signal to one case to avoid a microphone cable from being complicated and to prevent a low frequency area from being lifted even when plural microphone signals are summed. SOLUTION: A microphone 11, an amplifier to amplify a level of a microphone signal and a filter 13 to suppress a low frequency component of the amplified microphone signal are housed in one case. First a variable resistor 12 adjusts a sound signal picked up by the microphone 11 to a proper sound volume. Then, the high pass filter 13 suppresses the low frequency component of a microphone output signal. The resulting signal is summed to a signal inputted to an input terminal 14 and the summed signal is outputted from an output terminal 16. In this case, a power supply for these electronic components is supplied with power from a power supply input terminal 18. |
