Apparatus for adjusting a signal and prohibiting adjustment of the signal based on a position of a movable member

摘要

A signal adjusting apparatus includes a movable member, a setting device, and a prohibiting device. The movable member is movable in a movable range to have the electrical signal adjusted in accordance with a position of the movable member. The setting device sets a prohibition range in the movable range. The prohibition range is a range where a volume level of the electrical signal is to be constant. The prohibiting device prohibits the volume level from being adjusted under the state that the movable member is located in the prohibition range.