Home > Circuit Blox > Microphone Amplifier
UPDATED:.20:57 23 August 2014
FUNCTION BLOCK
FUNCTION


This amplifies sound from a microphone.

  • The amplifier has a fixed gain of -212
  • The output can be adjusted from 0-100% using VR1

Supply Voltage (+V): 6 to 18 volts.
CIRCUIT DETAILS
+Mic
-Mic
PCB LAYOUT

PCB size: 51mm x 25mm

Assembly Instructions
+V
Vout
0V

NOTES

  • This circuit uses an operational-amplifier IC
  • It is an "inverting" amplifier which means a positive input will give a negative output, and vice-verca. This will not matter in most cases.

The gain of the amplifer can be calculated:

Gain= -R6 / R5

so in the above circuit this works out to be:

    Gain = - 1000000 / 4700 = -212

APPLICATIONS:

  • Public address system
  • Sound/frequency measurement
  • Sound level meter
  • Guitar amplifier
  • Sound effects
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