Digital filter for an electronic musical instrument

A digital filter system for an electronic musical instrument comprising:

• a plurality of digital filters of different constructions;
• and
• connection switching means for setting a combination of connections between said digital filters and for selectively switching said combination of connections in response to a selection signal,
• a digital tone signal being applied to said digital filter system imparting the tone color determined by the combination of connections set by said connection switching means.

A digital filter system for an electronic musical instrument comprising:

• a plurality of digital filters of different constructions;
• and
• connection switching means capable of setting a combination of connections between said digital filters and selectively switching said combination of connections in response to a selection signal;
• a digital tone signal applied to said digital filter system being imparted with a tone color determined by the combination of connections set by said connection switching means, and wherein;
• at least one of said digital filters is a pole filter capable of controlling a peak in an amplitude-frequency characteristic and at least one of said digital filters is a zero filter capable of controlling a valley in an amplitude-frequency characteristic;
• and wherein
• said determined tone color is characterized by a format having both a peak established by said at least one pole filter and a valley established by said at least one zero filter.

An electronic musical instrument comprising:

• keyboard means having a plurality of keys;
• tone signal generating means for generating a digital tone signal corresponding to a depressed key among said keys;
• tone color setting means for setting a tone color of a tone to be produced;
• filter coefficient generating means for generating filter coefficients corresponding to said set tone color;
• digital filtering means, connected to said tone signal generating means and said filter coefficient generating means, and including a pole filter capable of controlling a peak in an amplitude-frequency characteristic and a zero filter capable of controlling a valley in an amplitude-frequency characteristic respectively provided in a transmission path of the digital tone signal, said filter coefficients for controlling said peak being applied to said pole filter and said filter coefficients for controlling said valley being applied to said zero filter;
• digital-to-analog converting means for converting said filtered digital tone signal to an analog one;
• and
• sound means for producing a tone corresponding to said converted analog tone signal, said set tone color being imparted to said tone.

A electronic musical instrument comprising:

• keyboard means having a plurality of keys;
• tone signal generating means for generating a digital tone signal corresponding to a depressed key among said keys;
• tone color setting means for setting a tone color of a tone to be produced;
• filter coefficient generating means for generating filter coefficients corresponding to said set tone color;
• digital filtering means connected to said tone signal generating means and said filter coefficient generating means, including a plurality of digital filters of different constructions and connection switching means for setting a combination of connections between said digital filters and for selectively switching said combination of connections in response to a selection signal, and filtering the digital tone signal with characteristics determined by the combination of connections of the digital filters set by said connection switching means and said filter coefficients;
• digital-to-analog converting means for converting said filtered digital tone signal to analog one;
• and
• sound means for producing a tone corresponding to said converted analog tone signal, said set tone color being imparted to said tone.