Why don't 3.5mm headphones use electricity?

The reason why 35mm headphones don't use electricity is because it uses the traditional analog audio transmission mode. This kind of earphone generates sound by using the voltage of transmitting audio signals through the earphone jack connected to audio equipment. It does not need an extra power supply, because it directly depends on the audio signal provided by the device itself.

In contrast, some headsets and headset technologies require the use of power, such as Bluetooth headsets and noise-canceling headsets. These headphones are usually built-in or battery-powered, and support Bluetooth connection or noise reduction.

It should be noted that although the 35mm earphone does not need electricity, its sound quality and function are limited by the connected equipment. Therefore, selecting high-quality audio equipment and appropriate audio file format can improve the sound quality of 35mm headphones.

In addition, with the development of technology, more and more headphones adopt digital audio transmission methods, such as USB-C headphones and Lightning headphones. These headphones need to convert digital audio signals into analog signals through a digital signal converter, which may require additional power supply. This development further improves the function and sound quality of headphones.