This circuit was found in a publication of1994, originally obtained from the National Semiconductor manual. The National is now a company of the Texas Instruments group. The circuit uses two LM388 bridged, providing an output of 4 W. The power can be made by simple supply of 12 V with at least 1 A. It uses 8-ohm load as speaker. The pins 3, 4, 5, 10, 11 and 12 must be connected to a larger area of the copper-plate to serve as a heatsink.
