In the diagram from the November 1999 Electronics Now magazine we have the way to improve both the gain and the stability of the LM386 amplifier.
An advanced motor control software plug-in for Microchip’s MPLAB® X Integrated Development...
This relay without lock uses a general-purpose transistor. The relay is according to the supply....
This signal follower is from a 1970's documentation. So it uses the traditional configuration at the time...