This differential amplifier, found in a 1964 Electronic Design, has a gain of 30. The setting can be applied to modern equivalent transistors.
We found this circuit in an English documentation from the 60s. The integrated circuits are the...
This circuit was found in a 90s Popular Electronics. It generates tones given by the oscillators and...
This amplifier circuit applies its signal to an ordinary audio amplifier to pick up signals from a...