This circuit amplifies signals from 0.5 Hz to 300 kHz. We found it in an old documentation. Equivalent transistors may be used. The gain is 20 dB.
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...