Microphone Mixer

This relatively simple mixer was designed for three dynamic microphones, but can be re-designed for more or less. Level and tone controls are available to tailor the sound to your needs.

Schematic


Schematic for mixer

Parts:


Part Total Qty. Description Substitutions
R1, R2, R3 3 1K 1/4W Resistor  
R4, R5, R6 3 10K Logarithmic Pot  
R7 1 1Meg 1/4W Resistor  
R8, R10 2 10K 1/4W Resistor  
R9, R11 2 100K Linear Pot  
C1, C2, C5, C6 4 0.1uF Ceramic Disc Capacitor  
C3, C4 2 22nF Ceramic Disc Capacitor  
U1, U2 2 741 Op Amp  
J1, J2, J3 3 Input Jacks Of Your Choice  
MISC 1 Board, Wire, Knobs, IC Sockets  

Notes:

1. R1-R3 are level controls. R9 and R11 control bass and treble, respectively.

2. Since the circuit draws such low current, two 9V batteries can be used for a power supply.

3. Building the mixer in a metal case will cut down on noise.