How do you remove the insulating paint from the copper wire?
Press the tin with soldering iron and the soldering flux to hold the wire for a little longer. The headphones are very thin, and fire or knife will damage the wires and break them easily. It's not easy to break with my method. Groped by oneself.Other rough wires are better with a knife.
Press the tin with soldering iron and the soldering flux to hold the wire for a little longer, then scrape with the nail.
Use a small knife to gently scratch, and pay attention to the road.
You can burn it with a lighter, but at a faster rate, just a moment's fire, and then use your nails repeatedly burned.