Steps:
1. Some parts we need in this project.
![](https://cdn.hackaday.io/images/9264081583160443999.png)
![](https://cdn.hackaday.io/images/4464531583160458747.png)
![](https://cdn.hackaday.io/images/116391583160498217.png)
![](https://cdn.hackaday.io/images/2536711583160511348.png)
![](https://cdn.hackaday.io/images/7361461583160523257.png)
![](https://cdn.hackaday.io/images/5631401583160531805.png)
2. The main steps to make the circuit.
![](https://cdn.hackaday.io/images/9383301583160555806.png)
![](https://cdn.hackaday.io/images/6694321583160568741.png)
![](https://cdn.hackaday.io/images/7419501583160577561.png)
![](https://cdn.hackaday.io/images/4138951583160589695.png)
![](https://cdn.hackaday.io/images/2595741583160598933.png)
![](https://cdn.hackaday.io/images/8272551583160612692.png)
![](https://cdn.hackaday.io/images/220911583160638727.png)
![](https://cdn.hackaday.io/images/7020181583160650206.png)
![](https://cdn.hackaday.io/images/9125301583160658439.png)
3. Connect it to speaker and cellphone then test it.
![](https://cdn.hackaday.io/images/2314781583160714205.png)
![](https://cdn.hackaday.io/images/5832191583160725956.png)
![](https://cdn.hackaday.io/images/9080191583160733181.png)
![](https://cdn.hackaday.io/images/3084401583160740446.png)
Product list:
D718 transistor https://www.utsource.net/sch/D718
1000uf 25v capacitor https://www.utsource.net/sch/1000uf%2025v%20capacitor
4700uf 25v capacitor https://www.utsource.net/sch/4700uf%2025v%20capacitor
680ohm resistor https://www.utsource.net/sch/680ohm
474pf 100v
500k volume
More details, pls check the video on Youtube: