| 摘要 |
<p>PURPOSE:To enable to perform a high-precise tuning, by a method wherein, using a CPU, a period of a fundamental wave included in a musical tone signal is measured, and a difference between the period and a reference frequency is displayed. CONSTITUTION:A musical tone signal from an input terminal 1 is supplied to a synchronous oscillator 10, acting as a fundamental wave signal sending circuit, via an amplifier 2. Then, the synchronous oscillator 10 fetches a fundamental wave signal, included in the musical tone signal, to supply it to a CPU13. The CPU13 counts a time during the predetermined periodicity of the fundamental wave signal by means of a clock signal from a crystal vibrator 14. A deviation amount between the counting value and a reference frequency assigned by a tuning string assigning circuit 12 is computed to display it in a display 18. As noted above, a firm numeral circuit for a resistance, which fluctuates due to temperature, and a capacitor to perform a high-precise tuning.</p> |
