All that is needed to build an audio amp are a few external components most of which are decoupling capacitors. It is well suited to low power applications
and runs just fine on a 9 volt battery or any voltage supply from 4-12
volts. It has a low quiescent current drain of only 4mA so it won’t kill
a battery right away if you leave it on and idle. The gain is
internally set to 20 but the addition of an external resistor
and capacitor between pins 1 and 8 will increase the gain to any value
from 20 to 200. An increase in bass frequency can be facilitated by
adding a 10K resistor and .033 uf capacitor in series between pins 1 and
5.
