Mains noise problem and reduced sensitivity

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I had tried to build an audio amplifier using a preamp build out of a transistor and thereafter using lm386 for the audio amplifier. I had received a suitable response using an earphone. But when I use an 8 ohm 0.5 speaker the audio output gets distorted and also the sensitivity reduces. Also I am unable to eliminate the mains noise which distorts the output of the speaker. Along with it when I increase the volume control or the gain control too high i hear a sharp beep sound of 2.7 kHz. I would love to hear what improvments i could make in the circuit to make it sensitive as well as clear
 

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Concentrate on just the part around the LM386 for now. Make sure you understand the component values. 100uF is 100 microfarads. 100mF is 100 millifarads which is 100,000uF. That's enourmous and a non valid value for something like this.

These show correct examples that will work.
 

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