3 Transistors Make Amplifier Circuit

In this project, we are going to teach you making one of the best quality amplifier circuit. It is a very cheap and simple amplifier circuit that you can make at home easily. The most interesting part of this amplifier circuit is that, using only DC-12v power supply you can operate this amplifier circuit. For this case, you can use this amplifier circuit at your home, office, inside a bus, car, track and other places also.

The final circuit diagram and design can be seen above. We also thanks to our sponsor JLCPCB (https://jlcpcb.com/RTA) for sponsoring us PCB for this project.

Thanks To JLCPCB.

$2 for 1-4 Layer PCBs.

Get SMT Coupons - https://jlcpcb.com/RTA

Since it is a very cheap amplifier circuit, to make this powerful amplifier circuit, you might need some electronics component. Those component list with value have to been given below.

Component List –

1. Transistor – D 1047

B 817

BC 547

2. Volume – B 100K

3. Resistor - 1 KΩ

2.2 Ω

100 Ω

4. Capacitor - 100µf/ 35v

4.7µf/ 50v

5. Diode - 1N 4007

6. Power Supply – DC 12v

7. Speaker

8. Audio Input Cable

9. PCB (JLCPCB)

Here the amplifier circuit, we made for you, that was D-Class amplifier circuit. To adjust volume, we just use B-100K potentiometer/ volume. We don’t add power supply circuit with this amplifier circuit. For power supply you can use 12v battery or 12v adapter circuit. The schematic of 12v power supply circuit design along with the PCB layout can be seen above.

We everybody knows that, all kind of transistor contain 3 legs. And all 3 legs have 3 different names. To make this amplifier circuit connection, 1st we need to know about the pin out of this 3 transistor.

D 1047 – D 1047 is an NPN transistor. If we count it’s leg from left side, then 1st leg “Base” 2nd leg “Collector” and 3rd leg “Emitter”

B 817 – B 817 is an PNP transistor. If we count it’s leg from left side, then 1st leg “Base” 2nd leg “Collector” and 3rd leg “Emitter”

BC 547 – BC 547 is an NPN transistor. If we count it’s leg from left side, then 1st leg “Collector” 2nd leg “Base” and 3rd leg “Emitter”

You know that, it is a transistor make amplifier circuit. For that to make this circuit 1st we need to connect transistor with circuit. We connect D-1047 and B-817 transistor with circuit. We connect D-1047 transistor at left side and connect B-817 transistor at right side.

Now we connect 2.2 Ω resistors with D-1047 and B-817 transistor. We need 2 pieces resistor to make this amplifier circuit. We connect this resistor with both transistor emitter leg and then connect both resistor empty legs.

Then we need to connect two rectifier diode to make this amplifier circuit. We connect one diode negative leg with Base leg of B-817 transistor and then connect another diode positive leg with Base leg of D-1047 transistor. We connect two diode two terminals with two transistor. Now we connect this two diode empty terminal.

Now we connect 1K resistor with circuit. We connect this resistor with Base and Collector leg of D-1047 transistor.

Now we connect BC-547 transistor with circuit. We connect this transistor collector leg with Base leg of B-817 transistor and connect BC-547 transistor emitter leg with Collector leg of B-817 transistor.

In the next step, we need to connect capacitor with circuit. 1st we connect 4.7µf/50v capacitor with circuit. We connect this capacitor negative leg with Base leg of BC-547 transistor.

After this step, we connect 1000µf/35v capacitor with the amplifier circuit. We connect this capacitor positive leg with 2.2Ω resistor.

To adjust volume, now we need to connect B-100k volume with the circuit. We connect 4.7µf/50v capacitor positive leg with output leg of volume. Then connect Audio input cable with input leg of volume.

All kind of electronics component is now connected with the amplifier circuit. Now we need to solder the circuit.

It’s the time to soldering and cut-off all extra leg of electronics component. Now we solder all component leg carefully and to make sure we need to check all of them for several times. We also remember that, there should not be any kind of short circuit connection. For perfect inquiry, we should use liquid PCB cleaner to wash PCBs.

Thanks to JLCPCB, for sponsor us such a quality PCB board.

To input audio, now we connect audio input cable with the circuit. We connect audio input “Ground” cable with input leg of volume/ potentiometer and connect audio input “Right” cable with the empty leg of volume.

To operate this amplifier circuit, we are using only DC-12v power supply circuit. We connect this 12v power supply negative cable with Collector leg of B-817 transistor and connect positive cable with collector leg of D-1047 transistor.

For audio output, now we need to connect speaker cable with the amplifier circuit. We connect this speaker cable with volume and negative leg of 1000µf/35v capacitor.

Our circuit is now, finally ready for use. We just connect audio device with audio input cable and plug-in power supply of this amplifier circuit.

Play music and enjoy the sound.