US Patent 7915510 Tuner for musical instruments and amplifier with tuner

A tuning device includes an input terminal configured to receive an input electrical signal and a pitch detector to detect a pitch of the input electrical signal. A manual pitch designator designates a standard pitch from pitches of a scale. An automatic pitch designator designates a standard pitch from a scale that is closest to the pitch of the input electrical signal. A mode selector selects either a manual mode where the standard pitch is designated by the manual pitch designator, or an auto mode where the standard pitch is designated by the automatic pitch designator. A pitch comparator compares the pitch of the input electrical signal and the standard pitch and a display device displays the results of the comparison. The display device is configured such that when the standard pitch is designated by the automatic pitch designator, the standard pitch is not displayed.