This is a class AB audio power amplifier circuit which built using a TDA2002 or TDA2003 power amplifier IC module. These are replacements for the original LM383 which is no longer available. It is easy to build and has a minimum of external components. The module has both short circuit protection and thermal protection. It can drive loads as low as 1.6 ohm and is capable of delivering over 10 watts from a 16 V supply.

Component parts:

Here the circuit diagram of 25 watt high fidelity audio amplifier that build based on single Power Amplifier IC LM1875.

Component part list

R1 _____________ 1K
R2 _____________ 1M
R3 _____________ 22K
R4 _____________ 10K
R5 _____________ 180K
R6 _____________ 1R

IC1 ____________ LM1875

C1 _____________ 1uF 50V
C2,6 ___________ 100nF
C3 _____________ 22uF 63V
C4 _____________ 0.22uF
C7,5 ___________ 220uF 50V     

Miscellaneous:
Fuse holder & cover
2 amp fuses

Circuit Desc:
The IC can be used with two power supply arrangements single supply and dual supply. We have decided to use the dual supply version. The single supply version would require the use of 63V electrolytic capacitors, thus increasing the cost and overall size of the module.

This is 2x1W stereo audio amplifier circuit based on single IC KA2209. IC KA2209 is an equivalent IC to the TDA2822, you can use TDA2822 if you can’t find KA2209. It is ideal for battery powered operation. Power output depends critically on speaker resistance & supply voltage. At 3V into 4 ohm speakers the power is 0.1W. At 6V into 4 ohm speakers it is 0.65W. At 9V it is over 1W.

Components:

R1 R2_______10K
R3 R4_______4R7
C1__________10uF mini
C2, C3______470uF/16V
C4, C5______100uF/25V
C6, C7______100nF
IC__________KA2209/TDA2822
IC socket___8 pin