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
TDA1524A tone control.rar6 KB
TDA1524A tone control 7.0 version.rar6 KB
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 : )