: Connect one end to your playback device (smartphone, PC, or MP3 player) and the other end strictly to the center 3.5mm jack on the 2B.
You cannot "install" audio files onto the 2B’s internal memory—it has none for user files. The term "estim 2b audio files install" actually refers to playing those files through the 2B from an external device.
Plug one end of the stereo cable into your computer/phone headphone jack. Plug the other end into the socket of the 2B. 2. Set the Mode Turn on the 2B. Double-press the SELECT button to enter mode selection.