Description:
End of ultra low noise electret microphones pre-amp amplification board, using ST imported K472 electret microphones special amplifier chip, chip with low noise.Gain adjustable, power supply wide,and can be difference output, can also be single-ended output.
Gain adjustment: resistance R3 is gain adjustment resistance, when the default delivery is 30 db (resistance to 1 k), if not appropriate, can consult the table below change R3 resistance to obtain different gain, changes the resistance when the need to take off the original R3 SMD resistor (if you feel bad patch welding, welding the R3 can also use the
 plug-in beside two reserved welding plate above (gain is 0 to 40 db variable).
 Microphones connected: microphones positive + and negative -, GND on the board as a shield, don't need connected microphones (also can not meet, meet, but it is better to avoid interference)
 
 Specifications: 
 
 Difference Output: connect signal +, -, middle is GND grounded.
 Single-ended output: connect signal +, middle GND connect grounding
 Dual -channel output : signal +when a channel, signal - when a track, GND grounding in the middle
 Three kinds of output connection can choose according to need
 Operating voltage: DC 2.3 V to 5.5 V 
 Color: red
 Size: 15*23MM
 Material: Electronic component 
 Package Include: 
  1 x K472 Electret Microphone Power Amplifier Chip Board Module with Low Noise Gain Adjustable DC 2.3V-5.5 Replace MAX9812 
 
 
 
 

