Very strong audio spikes in a headset can damage the ear. This circuit, from a 90s Popular Electronics cuts them, being originally indicated to operate with an integrated amplifier of the time.
This circuit for signals around 4.5 MHz for old analog TV was found in the September 1992 Radio...
The circuit shown is a commercial electronic voltmeter sold in Japan in the 1960s. The circuit is fully...
This 80's circuit can be implemented with modern equivalent FETs with lower on resistance. The...