Ok now I can feel the delay!!!!
want to show me how I can merge this two scketches now???? 
I'm tryng to build even the LM386-N4 circuit amp, but I can't figure out how to power the IC... in the schematics you say its better to separate the power...
but how could do this? For my Auduino I use an arduino mega powered via usb.... I prefer not to use a battery... have you some advice for this?
Its a stupid idea try to power the circuit with the arduino mega??
G