this situation should be caused by the use of cheap double volume potentiometers. It is difficult for the resistance values of the left and right channels of the potentiometer to be completely equal. When the sound is very small, the resistance value of the right channel is larger than that of the left channel, which may lead to the silence of the right channel, but the left channel can still make noise. This is not a broken ear amplifier, but a poor component quality.

If you don't find any deviation when listening to music at normal volume, this problem is basically ignored.