This is Make a simple power amplifier – LM 380. Almost all the components are contained in a single 14 pin package and requiring few external components.

The supply voltage can be from about 8 volts to not more than 15 volts. The device is supposed to have internal current limiting and be almost indestructable. I find that the output is a little distorted and, with the small output power, is of little more use than just driving headphones so I prefer to use an AF power amplifier with a little more “grunt”. I have included it for reference just in case you need something really small and does not need a heatsink.
simplest AF power amplifier

I have a PCB foil pattern for this amplifier which I will include as soon as I have it in electronic format. This circuit is probably my most used AF power amplifier circuit in my own homebrew equipment.