If you turn down the volume knob to the extent that the sound is barely heard, one side may be heard slightly louder.
As you turn up the volume to secure proper sound volume when listening to music, the balance of left and right will be stable.
Due to the characteristic of the stereo type analog volume controller where one volume knob controls the output of left and right channels, there are minute deviations. Thus, please do not use it at too low volume. If the impedance of the headphone or earphone is not so high, it is advisable to reduce the window volume or player volume and adjust the analog volume controller to over 9 o’clock direction.