Last time we used an LM386 amp to try and amplify the sound from a standard ‘condenser’ microphone. It didn’t work that well and we didn’t have that much time to try and play with it to get it working better. So we’ll be lazy and just change the amplifier for an LM380 power audio amplifier instead. I’ll give you one on Wed 21st Sept 2016.
We’ll try a couple of circuits. Lets try this one first:
Then we could try: http://jonandnine.blogspot.my/2013/07/amplifier-using-lm380n-8.html
Third suggestion: The second diagram on page 4 of this pdf: http://physics.indiana.edu/~shylee/P108/p108_12F/11_X_Audio_Amplifier.pdf even though we don’t have 15V (our power plugs are only 12V) so we may get some clipping of the the audio output – perhaps (I’ve not analysed the circuit), but hopefully not..