Simple one transistor Amplifier input is 10 mV
Gain is 150
This version is self biasing so will work.with transistors with different HFE or forward Current Gain
You also use this circuit as current to voltage convertor if baised properly eg you can insert a Light Dependent Resistor LDR in parallel with 100k and in series with 100k trim pot in place off 42k then the output voltage will be a function off light falling on the LDR you will have to experiment
