This audio circuit was published in a Rado Electronics issue from October 1963. The transistors are from the time and the output is low impedance. Power is supplied with a voltage of 12 V.
This sophisticated alarm with traditional components was found in an ancient American...
This circuit is from a Fairchild digital clock module shown in the March 1977 issue of Radio...
This circuit was obtained in a Radio Shack documentation from 1977. It can be used as a multimedia...