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 compact power supply can be used on the workbench for up to 1 A load. The transformer has 1 A secondary...
This amplifier with an OTA has a gain of 40 dB. The power supply must be symmetrical. Found in...
This circuit was published in an English magazine from 1980. The magazine no longer exists, but...