DIY_YID

Thank you for your comment. If you want to make a bigger sound you should repalce the small speaker to a big speaker and you should redesign the circuit that take the impedance into consideration. The power of this small speaker can not perform a bigger sounds effects as the power of it limits you in doing this

probably not, because the changing is not obvious when you rotate the potentiometer for a small scale and if you rotate it for a big scale, the self-generated signal may be distortion. So for learning purpose I recommend you to replace the resistor R1 and R2 with other values and observe the changing

Yes, we can use a variable resistor to tune it

Very nice and fantastic, it shows passionate view of technology

You are right! Thank you very much.

Very nice project! I wonder how do you embed the image in the paragraph, I cannot find the method to do that. Thank you very much.

I found that it was not the premium membership problem. The new version of Instructables no more support editing HTML scripts. Maybe you are the earlier user since 2013 that you still have access to the old version of Editor. I got this information from https://www.instructables.com/community/how-to-emb...andhttps://www.instructables.com/How-to-Make-an-Instructable-Using-the-New-Editor/

Thank you so much for your answer. It's a pity that I don't have access to the html code editor that forbid me to embed formula in the paragraph in my Instructables.

Interesting instructable!

I am so sorry for that I asked for the factory to get the diagram of copper side of the PCB this afternoon. They said that they didn't keep this file and just keep the gerber file for manufacturing purpose. This DIY kits is used for learning fundamental circuit knowledge that it is enough to analyze and rebuild this circuit with the circuit diagram in this instructable. Don't worry about anything, I am glad to spend time on assisting you with this job. Thank you for your understanding.

That's great! Good luck ^_^

Thank you very much for your comment. With the two images I've attached against this reply you can easily to track the routes of all the components as each component do have the respective symbol printed on the PCB.