Introduction: Sound Amplifier With TDA2050 and Equalizr With 741 Opam

In this proyect, i made a sound amplifier, with 32 watts of power.

I am going to explain what materials you will need, how to built it, and how to prove it.

Materials for the sourcing supply +/-18vdc (for the TDA2050):

*1 transformer 24Vac-2 Amps.

*1 copper plate.

*2 terminals.

*3 dupont cables female-male.

*1 diode bridge. 50v-2 Amps.

*2 electrolytic capacitors. 4700uf.


Materials for the negative sourcing for the opams 741:

*1 integrated circuit LM337.

*2 electrolytic capacitor. 1uf.

*1 resistor. 120 ohms.

*1 potenciometer. 5 kohms.

*2 dupont cables male-male.

Materials for the positive sourcing for the opams 741:

*1 integrated circuit LM317.

*1 electrolytic capacitor. 1uf.

*1 electrolytic capacitor. 10uf.

*1 polyester capacitor. 100nf.

*2 diodes 1n4001

*1 resistor. 240 ohms.

*1 potenciometer. 5 kohms.

Material for the sound amplifier with TDA2050:

*1 integrated circuit TDA2050.

*1 electrolytic capacitor. 1uf.

*2 polyester capacitors. 100nf.

*2 electrolytic capacitors. 220uf.

*1 electrolytic capacitor. 22uf.

*1 electrolytic capacitor. 0.47uf.

*2 resistors. 22 kohms.

*1 resistor. 680 ohms.

*1 resistor. 2.2 ohms.

*1 speaker 5-10 watts/ 8 ohms.

*1 heat dissipator

*1 heat dissipating paste

Materials for the equalizer:

*1 3.5mm cable with auxiliar IN male-male.

*1 3.5mm input jack.

*5 dupont cables male-male.

*15 integrated circuits 741 OPAM.

*4 polyester capacitors. 33nf.

*4 polyester capacitors. 1nf.

*3 potenciometers. 250 kohms.

*4 resistors. 18 kohms.

*4 resistors. 20 kohms.

*4 resistors. 33 kohms.

*4 resistors. 43 kohms.

*4 resistors. 68 kohms.

*3 resistors. 12 kohms.

*4 resistors. 39 kohms.

*7 resistors. 10 kohms.

Step 1: Making the Sourcing Supply for the TDA2050

1.- in this step 1 you have to built the sourcing supply for the integrated circuit TDA2050.

In the datasheet of this integrated circuit, indicates that this device needs +/-18Vdc aprox. So you need more power than a normal 12Vdc supply. And obviusly you need a big current demanded by this device.

2.- you can built the sourcing supply how the schematic diagram show us.

3.- you can see the sourcing supply welded in a copper plate in the next picture, because is a quick and easy way to transport the source.

4.- at the end of the schematic diagram you can watch with a multimeter the Vout. And theres going to be -18Vdc/+18Vdc.

5.- i uploaded the datasheet of the TDA2050 in this step. This allows you to see the test circuit of this device.

Step 2: Making the Negative and Positive Voltage Regulators for the 741 Opams

1.- secondly is built the negative and positive voltage regulators.

the integrated circuit 741 Opam, needs about 5Vdc(minimum) to 15Vdc(maximum). If you put more voltage that 15Vdc you can damage the device and this can't get work any more. And by the moment we need this devices because they are going to be the equalizer, for getting the bass, middles and trebles. In an electronic explanation, we are going to use the 741 for making many configurations with the opams.

2.- there are the pictures of the schematics diagrams about the negative and positive regulators.

3.- there is the datasheet of the 741 opam

4.- there is the datasheet of the integrated circuit LM317.

5.- there is the datasheet of the integrated circuit LM337

Step 3: Built the Equalizr

1.- this step is difficult. You have to follow the pictures and the schematics diagrams. May be you can get lose with the pictures because i had to cut all the schematic diagram in sections. But don't worry i uploaded the complete schematic diagram in two files. The first file is in PROTEUS 8.3 (if you don't have this software, check the following link:, in this file the schematic diagram is in color, and is easier to identify the sections of the equalizer. The second file is in PDF, but, the schematic diagram is in black and white.

2.-the reasons about the sections of the equalizer are the follwings recomendations:

*The equalizer is a configuration of the 741 opams.

*These configurations are called filters.

*These filters are active filters (active filters beacuse they use Opams).

*To get the bass you need a filter low pass.

*In this case we get the bass frecuencies.

*In this proyect we use a frecuency about 260 HZ for the bass.

*To get the middles you need a filter band pass.

*Is a combination of high pass + low bass.

*We use frecuencies about 500HZ to 2 kHZ.

*To get the trebles you need a filter high pass.

*In this case we get the high frecuencies.

*In this proyect we use a frecuencies about 4.1kHZ.

3.- For the circuit in physics, you need the breadboard and all the material mentioned at the beginning.

4.- You can see how is the circuit in physics in the picture.

5.- The last step, in this big step to complete your equalizer, is built a configuration of the 741 opam called inverting summing amplifier. It consist in join the three filters (low pass, high pass and band pass) in one integrated circuit. Because the output of this integrated circuit is in the input of the Sound Amplifier with the TDA2050.

notes: in the physic circuit you can see that i used integrated circuits with 4 opams, each one, to make the filters. i am going to upload the datasheets of this devices. (TL084, Lf347).

Step 4: Built the Sound Amplifier With the TDA2050

1.-This circuit is easier. Is more compact, and you can use only one breadboard.

You can follow the picture or you can use the datasheet of the TDA2050.

2.- As you can see in the physic circuit, i had to use a heat dissipator because this device demands a lot of current in the moment of working. This device brings about 32 watts of sound power.

3.- Also you can look in the breadboard that i had space for the voltage regulators. the negative and the positive.

Step 5: The Moment of the TRUTH (proving the Sound Amplifier and the Equalizer)

only you have to conect the speaker with the sound amplifier.

i recommend to use alligator cables.


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