| 摘要 |
<p>PURPOSE:To facilitate changing of a reference pitch and to enable to perform a high-precise tuning even if the pitch is changed, by mounting a pitch changing switch which instructs a change in a step of a reference scale frequency. CONSTITUTION:A musical tone from an input terminal 1 is supplied to a synchronous oscillator 10, acting as a fundamental 1 wave signal sending circuit, via an amplifier 2. The oscillator 10 fetches a fundamental wave signal, contained in the muscial tone signal, and supplies it to a CPU13. The CPU13 measures a periodic time of the fundamental wave, and a difference between the measurements and a reference scale frequency, assigned by a string assigning switch 12, is instructed to a display 8. Additionally, the CPU13 changes in order the step of the reference scale frequency according to an instruction of a pitch changing switch 12g. This permits the easy changing of a reference pitch and enables to perform a high-precise tuning because of no change in a display position even if the reference pitch is changed.</p> |
