Afroman goes over the basics of how to use an op amp (operational amplifier) to amplify tiny voltages, and builds a circuit to listen to very faint sounds with a microphone.
LM324 Quad op amp: http://www.amazon.com/exec/obidos/ASI...
Circuit diagram: http://www.afrotechmods.com/groovy/am... Check out my webpage http://www.afrotechmods.com for more videos about electronics!
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