This circuit is from a 1967 publication. The configuration holds true for modern transistors having a feedback across R2.
We found this preamplifier for recording heads in a 1980s documentation. The circuit can be used...
Found in Popular Electronics' 90s, this small megaphone is based on LM386. The circuit uses a high...
This circuit with a common FET generates signals around 1 MHz, depending on the crystal used. We...