This circuit with the CA3059 was found in the July 1995 Elexctronics Now magazine. The signal must be DC, and the circuit is not isolated from the mains.
This circuit was obtained from an American 80's documentation. The transistors can be 2N2222 and...
This low Power simple amplifier is intended to the use with high impedance phones. The circuit is...
This circuit was found in a 1963 magazine, but can still be easily assembled with some current...