This amplified speaker is from a Radio Electronics from September 1988. The power integrated circuit is from that time and the other components are still common today.
The circuit shown in the figure below is suggested by ON Semiconductor (www.onsemi.com), based on...
This circuit is part of an article published in the March 1990 issue of Radio Electronics...
September 2016 - It can be obtained from Mouser Electronics the new ADC AD7779 from Analog Devices with...