Minimum of 12 Volt battery voltage, less than a sound or audio is issued less than the maximum and less good. You can assemble this circuit amplifier with a schema like this.
C3 = 100uF
U1 = SI1050GL
Electronic Circuit is a good site for hobbyist also who would like to try DIY because it shared good circuits. If you have a personalized circuit requirement you may feel free to request it through the comment box or contact me.