The LM386 is one of the most commonly used audio output chips in QRP radio designs.
This page is a collection of my notes and circuits that use this chip
There are a few variations of the LM386, most notably they are the LM368N-1, and LM386N-3. There is also a higher power version the LM386N-4
The main difference between the three is basically the operating voltage, power output.
LM386N-1, LM386N-3 Operating Voltage 4-12 volts
LM386N-1 250-325 mW output With 6 Volt Supply 8 Ohm Load
LM386N-3 500-700 mW output With 9 Volt Supply 8 Ohm Load
Typical Input impedance is 50K
Typical voltage gain is from 20x to 200x:
20x or 26 dB with a 1.35K Ohm resistor between pings 1 and 8 or
200X or 46 dB with a 10 uF capacitor between 1 and 8
National Semiconductor Data Sheet
LM386 Package and Pin Outs
A simple audio amp design.
Basic 200X audio Amp
Get rid of that noise and hiss
To help eliminate the hiss that the LM386 can exhibit only requires the addition of 2 components.
A 10K resistor and a 10pF capacitor
First appeared in SPRAT #79