1. Press the "Fn" key and "+" key on the keyboard to increase the volume.

2. Press the "Fn" key and "-" key on the keyboard to reduce the volume.

3. You can also use the volume control function that comes with FiiO KB1 music player by clicking the volume icon in the lower right corner of the playback interface or pressing the "V+" and "V-" keys on the keyboard. to control the volume.