We found this circuit in a documentation for radio amateurs from the 70s. The transistors can be the BC548. With it, small speakers of 4 or 8 ohms can be used as microphones.
This circuit was found in old documentation. The components can be replaced by modern ones. The...
This transistor circuit consists of a well-known bass and treble control configuration. The...
With the circuit shown, you can have a fast response with a Darlington configuration. The circuit is...