This balance indicator for stereo amplifiers was found in an 80's Elektor. The components used are common. Zeners are 1.8 V or close to that value.
This experimental flip-flip changes its state by the command of two push-buttons. The state is...
This 8 W amplifier with germanium transistors was found in a Japanese documentation from 1967. The...
This general purpose circuit was found in a Popular Electronics. It is intended for detecting the...