This circuit uses a crystal phone and can be built with more modern transistors like the BC548. The original circuit is from a 1979 publication and is powered with only two AA or AAA batteries.
This circuit was found in the September 1972 issue of Radio Electronics magazine. The circuit uses...
The circuit shown in the figure consists of an amplifier for stereo sources with Maxim's MAX9723...
This circuit was obtained in a 1980 edition of Elementary Electronics a magazine that no longer...