This circuit protects the speaker from dangerous direct currents that could damage it. The circuit is from an Electronics Experimenter Handbook 1993 edition.
The circuit shown in the figure serves as a pre-amplifier with a voltage gain of around 12 times,...
The amplifier shown can either excite a speaker in this low power version, or its input step can...
This circuit was found in a 1989 publication. The operational amplifier supports equivalents. The...