3 Channel Microphone Mixer Circuit with IC741 circuit is a basic 3 input mic mixer circuit with the popular opamp 741 ICs.
Two 741s are used here. U1, U2 are used as preamplifiers.
They produce a gain of around 40 dB to the individual input signals.
The U1 is wired as a summing amplifier to add the signals from three preamplifiers.
IC2 also gives a gain of around 5decibel to the final output signal.
Total gain of the system is around 45 dB.
Electronic Part List
- R1, R2, R3 1K 1/4W Resistor
- R4, R5, R6 10K Logarithmic Pot
- R7 1Meg 1/4W Resistor
- R8, R10 10K 1/4W Resistor
- R9, R11 100K Linear Pot
- C1, C2, C5, C6 0.1uF Ceramic Disc Capacitor
- C3, C4 22nF Ceramic Disc Capacitor
- U1, U2 741 Op Amp
- J1, J2, J3 Input Jacks Of Your Choice
Note
R9 and R11 control bass and treble, respectively and R1-R3 are level controls. Because the circuit draws such low current, we using 2 X 9V batteries that can be used for a power supply. You should be build the mixer in a metal case will cut down on noise.
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