This is a mono power amplifier circuit powered with single Amplifier chip STA5100. The chip will deliver single power output at 140 watt. For stereo application, just build two identical circuit and then doubled the power supply current output by increase the current value of the transformer. This amplifier powered using dual polarity (symmetrical) power supply.
140W Power Amplifier Circuit Diagram:
The circuit contains all the blocks to build a mono amplifier. It is based on the Output Bridge Power Amplifier, and its protection circuit. Moreover, the compression function and a signal rectifier are added to complete the circuit.
The operation modes are driven by The Turn-on/off sequence block. In fact the IC can be set in three states by
the Stby/mute pin:
Standby ( Vpin < 0.8V), Mute (1.6V < Vpin < 3V), and Play (Vpin > 4V).
In the Standby mode all the circuits involved in the signal path are in off condition, instead in Mute mode the circuits are biased but the Speakers Outputs are forced to ground potential.
Download the STA5100 datasheet from below link to know the characteristic of STA5100 140W audio amplifier chip: