32W Stereo Audio Amplifier





Introduction: 32W Stereo Audio Amplifier

special thanks to ALAMGIR NASIR

Who helped me make this project
                             The aim of the project was to make a stereo audio amplifier. in addition to this additional features should be that it should have volume control, bass control,treble control and left right control too.

                              For this project i used
1- Operational amplifier TDA2050 which is used in the main amplifier circuit
2- TDA1524 which is used in the pre-amplifier of the circuit.
3- I used the split DC power  ±22V as an external supply. The main advantage of the split supply over the single supply is that it is filtered from both sides (+) and (-) terminals and has the proper grounding system which are caused to decrease the output noise of amplifier but u can use single supply too.

Step 1: Pre-amplifier

                            The arrangment shown in the diagram is the pre-amplifier.The circuit is designed as an active stereo-tone/volume control for car radios, TV receivers and mains-fed equipment.
It includes functions for bass and treble control, volume control with built-in contour (can be switched off) and balance.
All these functions can be controlled by d.c. voltages or by single linear potentiometers.

                             It starts from the input power supply integrated into the 3 pin is the positive voltage and negative voltage to pin 8. This circuit will have only R and C classes of devices to filter out frequencies in different area.When the signal from the sound source enters into the pin 15 of IC1, the INPUT signal is coupling through the C1 and C2 signals of each channel.
Left and the right, then the IC will amplify signals with C6 and C4. C5 and C3 act as base (low frequency control) with VR1-VR4 to adjust the Volume, Balance, Bass and Treble, respectively.

                  see the image for part list

Step 2: Main Amplifier

                               TheTDA2050 is intended for use as an audio
class AB audio amplifier. Thanks to its high power capability theTDA2050 is able to provide unto 35W true rms power into 4ohm load @ THD= 10%,VS =  ±18V,f=1KHz and up to 32W into 8ohm load @ THD=10%,VS = ±22V,f=1KHz. Moreover ,theTDA2050 delivers typically 50W music power into 4ohm load over 1sec at Vs= 22.5V,f=1KHz.

This is a power amplifier and requires 200mV RMS for full output. Voltage gain is 30.5dB with resistor values shown. Closed loop gain is set by Ratio R1/R2. Increase R2 for less gain and vice versa. Power bandwidth is 20Hz to 80KHz. R3, C3 and R6, C11 form a zobel network to prevent high frequency instability.

The speaker is direct coupled, therefore no expensive large value electrolytics are needed and the bass will be crisp and clean. It is advisable to place fuses in the power supply (not shown).

R1,R4,R5,R8______22k 1/4W Resistor
R2,R7__________680R 1/4W Resistor
R3,R6___________2.2R 1/4W Resistor
C1,C10___________1u NP 25V Capacitor
C2,C12__________22u 63V Electrolytic
C3,C11_________0.47u 400V Polyester
C4,C7,C8,C9_____100n 400V Polyester
C5,C6,C13,C14___220u 63V Electrolytic
U1,U2__________TDA2050V 32W Audio Power Amp

Step 3: Power Supply

you can take any 2 power supplies from the market they can be 20V each or a single that can supply +-20V ..

i am sorry about the power supply
because i  myself used two regular power supply from the lab and converted +22V to 12V for the pre-amplifier using lm7812 IC whic is simple to make.

the configuration below can help u making power supply

Step 4: Testing(video)

here is the video if some one likes to see . 100% working .

if u have any problems u can ,ail me at

and if u like this instructable please rate it  : )




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    108 Discussions

    Just a heads up to all who wanna build this, the tda2050 is a discontinued amp and if you try to order it online you may get fakes, i bought 10 of these and 6 so far were fake and didnt work at all. Id recommend the tda2003 as a replacement, theyre cheap, reliable, and have a low amount of external parts, ive used it many times with great success!

    1 reply

    Thanks for giving the heads up, In my country they are easily available and mostly they are working, unless someone burns the IC while soldering.
    and for the second part tda2003 has very less output power its around 10W i guess whereas tda2050 has 32W so it pretty much depends on the usability.

    I have made an amplifier using tda2003 quite a while ago if someone is interested check out my other projects you will be able to find it there.

    What it will be if i connect the -22 and the ground to make the negative side of the power supply , and the +22 side o the positive side? it will work?

    1 reply

    I dont understand what are you trying to say so let me just tell what i think u are asking.
    u will never touch -22 with ground or it will short circuit and your battery might get fire/damage. There is no such thing as voltage. its always a voltage difference (which means if I have a 22V battery/Supply it implies that the positive terminal of the battery is 22Volts higher than the negative terminal) so If you want to generate -22V All you need to do is connect the Positive terminal of your battery with the ground of the circuit (Ground is generally at 0 Volts so) your negative terminal gets 22V lower than it (0 - 22 = -22V). Its just a perception of it. I repeat there is no such thing as negative voltage.

    I dont remember exactly, its been a long time but as an estimate it was approximately 30$ (amp+ preamp)


    2 years ago

    Hello. Can I ask if we can replace the pre amp circuit? Because the required ic is not available here. Thank you :)

    2 replies

    Hello. Yes you can replace the whole pre-amp circuit with any other pre-amp u want ... you can even ignore the pre-amp and just build the mail amp... pre-amp is just for tuning the sound.


    2 years ago

    how can i add the voice echo control in this, please guide?

    1 reply

    The pre-amp TDA1524A does not suppot echo effect, as i mentioned before it only controls the volume, bass and treble. To gain echo effect some other pre-amp (audtio processor etc) can be used. I googled it and fount this IC

    HT8972 Voice Echo

    I havent seen it in detail but it will work .. just make sure the output of the ic is compatible with the input of the main AMP.

    Yes you can use the main amplifier without the pre-amp. the purpose of pre-amp is to change bass, treble and volume.


    I cant open the:

    TDA1524A tone control .rar

    TDA1524A tone control 7.0 version.rar

    files. what do they contain?


    6 replies

    Hello, I just downloaded then and extracted them both are working fine. I am using winRar to extract these files. these files contain .lyt files (layout files) that can be opened in proteus.

    where can i download proteus? becuase i cant seem to find it.


    ok thanks, ya i can download it just not open it.

    guess i don thave the right program to open it. im trying proteus now.