This circuit was originally suggested by Texas Instruments, as it is based on one of its integrated circuits, the TLC251. This integrated is an operational amplifier with LinMOS field effect transistors and can operate with a voltage as low as that supplied by a single battery. Its consumption is only 10 uA and it provides a good 100 k ohm load output signal from dynamic medium and low impedance microphones. The 1 M ohm potentiometer adjusts the gain so that the amplifier excites. at the polarization input, a voltage can be applied that leads the circuit to a symmetrical response.
