This is a useful and simple 2 watt audio amp circuit using TBA820 amplifier IC. This is a great circuit to use as lab audio amplifier purpose. The circuit has a good output power with minimum components and low voltage. The input voltage can be 3V to 16V. This IC has a lot of good
features like minimum working supply voltage, low current consupmtion, good ripple rejection etc. On 16 volt supply use 16 Ohms speaker, on 12 volt use 8 Ohms speaker and use 4 Ohms speaker on 9 volts.