This circuit, which can be seen elsewhere on this website, was obtained from a 90’s English documentation. The circuit drives a small speaker, but for greater volume an external amplifier must be used.
This small audio amplifier is based on the LM390 with a minimum of external components. We found it...
The integrated circuit used is not common today. The circuit presents a bass boost according to...
This circuit provides two outputs of the same signal. One with the original phase and the other...