ITEM NAME:LM386 Electret Microphone Power Amplifier Board Gain 200 Times DC 3.7V- hfTECA Description: Using LM386 amplifier chip, magnification of 200 times, you can directly drive small power speakers, suitable for electret microphone amplification. Practical application: Deafness hearing aids: board connected to the microphone, power, headphones, is a good deaf hearing aids. Operating Voltage: DC 3.7V-12V Board Size(approx): 25mm x 25mm Packing List:.Find many great new & used options and get the best deals for LM386 Electret Microphone Power Amplifier Board Gain 200 Times DC 3.7V- hfTECA at the best online prices at shop2india!