I’ve playing around with the 386 Audio Amplifier. This is a really great chip. It has a lot of possibilities. Looking at all of the great circuits that use this I’ve noticed there are many different ways to set the gain.
Gain is set using pins 1 and 8. With these two pins open the Gain is 20. Connecting these pins, in any of the various ways, you get gains from 20 to 200. Or at least this what I think from reading the datasheet.
The image below shows 6 different methods I have encountered for setting the gain. The datasheet suggests method 2. Many projects use method 3. The datasheet suggests using method 2 and attenuating the input to create variable gain. Which I haven’t shown here.