| 摘要 |
<p>PURPOSE:To obtain the measuring instrument which makes a fast response and enables the turning of many kinds of rhythm by comparing a musical sound signal with a reference frequency signal by a phase-locked loop. CONSTITUTION:An musical sound-electricity converter 50 inputs a musical sound signal to the phase-locked loop 20. In addition to a program for operating a CPU 11, reference frequency data, rhythm data, etc., are written in a ROM 12. A VCO 21 is applied with a reference voltage for oscillating a reference frequency prescribed for each sound name to oscillate at the reference frequency of each sound name, the reference frequency is compared with the frequency of the musical sound signal, and their deviation quantity is displayed on a display unit 40. For the purpose, the phase-locked loop which is fast in the speed of the frequency comparing operation is used to easily tune even a percussion instrument whose sound attenuates in a short time. Further, reference frequency data stored in a memory is read out and supplied to the VCO, so reference frequency data on many kinds of rhythm can easily be written in the memory.</p> |
