Found in a 1990s Popular Electronics, this circuit uses two transistors to boost the power of a 741 with audio signals. The power depends on the transistors used, which can be general-purpose types.
This circuit was found in a 90s Radio Electronics. It is intended to amplify the sound channel of...
A bridge with greater sensitivity and, therefore, lower consumption for the microcontroller...
Found in a 1964 magazine, this is a small headphone amplifier from 500 ohms to 10 k ohms (magnetic...