The Mixer Pre MIC 3 channel by LM348-741×4

If you are looking for a mixer with a microphone, and can easily make your own.I highly recommend this circuit.It is a microphone pre-amplifier for 3-channel or 3-channel mixer itself. When looking at the circuit, we have featured the use of a single integrated circuit LM348. The internal structure of the four IC-741 ICs. When It costs was similar, thus allowing us to save all of IC-741 and convenient to use than one x 4pcs.
And we can adjust the volume, each microphone freely by VR1,VR2,VR3. But this circuit used to the dual power supply +12V -12V and GND that should be dc voltage regulator with IC-7812,7912 or transistor follow you want.....
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