Abstract: A keyboard unit includes: a key; a plurality of members which include the key, and each of which has an engaged section for forming an engaged state, the engaged state changed by turning of the key, at least a portion of the engaged section formed of a conductor; a detector which is configured to detect information on the engaged state of the plurality of members by detecting a conduction state between the at least portions of the engaged sections which are in contact with each other; and a determiner which is configured to determine a musical sound parameter based on a detection result of the detector.

Abstract: A soft-start generation system is configured to generate a soft-start voltage. The soft-start generation system includes sawtooth circuitry configured to generate current having a sawtooth waveform and staircase circuitry configured to generate current having an ascending staircase waveform. A ramp-up current may be generated that is a combination of the sawtooth current and the staircase current. The ramp-up current may continuously ramp up to a predetermined current level. The soft-start voltage may be generated based on the ramp-up current.