Takaaki Muto

Device for synthesizing a musical tone employing random modulation of a wave form signal

An apparatus for synthesizing a musical tone comprises a loop circuit for circulating an input wave form signal through a delay circuit, a wave form memory, and a random modulation circuit for modulating the wave form signal stored in the wave form memory. The random modulation circuit generates a random signal, such as a noise signal. The random signal modulates address data to the wave form memory, so that the read wave form data read out from the wave form memory is delicately varied with time.

Electronic musical instrument of delayed feedback type

In a tone signal synthesizer for synthesizing a tone signal by supplying a driving signal, into a closed loop circuit including a delay circuit and a filter, a filter coefficient which controls the characteristic of the filter is changed while a musical tone is generated. For example, a set of filter coefficients are provided at the time of key-on and are switched to another set of filter coefficients when a predetermined time is passed after the time of key-on. The set of filter coefficients are switched to a further set of filter coefficients at the time of key-off and then are switched to a still further set of filter coefficients when a predetermined time is passed after the time of key-off. It is possible to generate a musical tone which changes more complexly on the basis of the change of the filter characteristic, with the passage of time.