This very low frequency amplifier has a gain of 1,000 and was found in a 1967 documentation. The circuit is suitable for detecting explosions, distant echoes and seismic vibrations.
This circuit, obtained in a 1983 magazine, can drive loads up to 100 mA if the transistors are...
This JFET amplifier stage was found in the Encyclopedia of Electronic Circuits Volume 5 from 1995....
The circuit shown in the figure uses two of the four operational amplifiers found on the LM324...