This circuit can be used as an amplifier for musical instruments or even with your cell phone. The circuit is old and was found in the 1990 edition of Radio Electronics Experimenter magazine.
This circuit, found in a 90s Popular Electronics, uses a 0 to 1 mA milliammeter, which can be...
This configuration is from a 1966 publication. However, with small changes in component values it can...
I found this circuit in a 1978 publication. The circuit can be assembled with a BD136 transistor to...