This simple audio signal tracer or follower can be made with a BC548 instead of the original transistor. The output is made in a small crystal phone. The power can be from 5 to 9V.
This circuit was found in General Electric documentation from the 1980s. The circuit uses couplers...
We found this circuit on Motorola's 1993 Linear Interface ICs. Equivalent operational amplifiers can be...
The circuit in the figure is based on an LM101A; diodes can be replaced with equivalents. The...