Guitar synthesizer

A guitar synthesizer, comprising:

• a guitar portion (10) including strings stretched between a bridge and a nut and pickup means (12) associated with said strings for detecting a string vibration and providing a guitar sound signal in response to a string vibration, said guitar sound signal including a fundamental wave component and harmonics, signal source means (15) for generating a fundamental wave associated signal in response to said guitar sound signal, said fundamental wave associated signal having the frequency of said fundamental wave component included in said guitar sound signal, said signal source means for generating said fundamental wave associated signal comprising voltage controlled variable bandpass filter means (41) having a variable passband characteristic coupled to said pickup means and responsive to a control voltage for varying said passband characteristic in response to the frequencies of said guitar sound signal as a function of said control voltage, frequency/voltage converting means (42) responsive to said voltage controlled variable bandpass filter means for converting the frequency of the output of said voltage controlled variable bandpass filter means into a voltage representing the frequency of said output of said voltage controlled variable bandpass filter means (41), circuit means for applying said frequency representing voltage to said voltage controlled variable bandpass filter means (41) as said control voltage for adapting said passband characteristic of said voltage controlled variable bandpass filter means (41) to the frequency of said fundamental wave component included in said guitar sound signal, whereby said signal source means (15) is adaptively and dominantly responsive to the frequency of said fundamental wave component included in said guitar sound signal, voltage/frequency converting means (35) operatively connected to said frequency/voltage converting means (42) for providing a sound source signal having the frequency of said fundamental wave component included in said guitar sound signal, envelope signal providing means (31) responsive to said pickup means for detecting a signal envelope of said guitar sound signal and providing an envelope signal representing the envelope of said guitar sound signal, and sound synthesizing means (36) responsive to said sound source signal from said voltage/frequency converting means and to said envelope signal for modulating said sound source signal with said envelope signal for synthesizing a synthesized guitar tone, and wherein said frequency/voltage converting means (42) comprises sawtooth wave signal generating means responsive to the output of said voltage controlled variable bandpass filter means (41) for generating, as said fundamental wave associated signal, a sawtooth wave signal in synchronism with the frequency of the fundamental wave component included in said guitar sound signal.

A guitar synthesizer, comprising:

• a guitar portion (10) including strings stretched between a bridge and a nut and pickup means (12) associated with said strings for detecting a string vibration and providing a guitar sound signal in response to a string vibration, said guitar sound signal including a fundamental wave component and harmonics, signal source means (15) for generating a fundamental wave associated signal in response to said guitar sound signal, said fundamental wave associated signal having the frequency of said fundamental wave component included in said guitar sound signal, said signal source means for generating said fundamental wave associated signal comprising voltage controlled variable bandpass filter means (41) having a variable passband characteristic coupled to said pickup means and responsive to a control voltage for varying said passband characteristic in responsive to the frequencies of said guitar sound signal as a function of said control voltage, frequency/voltage converting means (42) responsive to said voltage controlled variable bandpass filter means for converting the frequency of the output of said voltage controlled variable bandpass filter means into a voltage representing the frequency of said output of said voltage controlled variable bandpass filter means (41), circuit means for applying said frequency representing voltage to said voltage controlled variable bandpass filter means (41) as said control voltage for adapting said passband characteristic of said voltage controlled variable bandpass filter means (41) to the frequency of said fundamental wave component included in said guitar sound signal, whereby said signal source means (15) is adaptively and dominantly responsive to the frequency of said fundamental wave component included in said guitar sound signal, voltage/frequency converting means (35) operatively connected to said frequency/voltage converting means (42) for providing a sound source signal having the frequency of said fundamental wave component included in said guitar sound signal, envelope signal providing means (31) responsive to said pickup means for detecting a signal envelope of said guitar sound signal and providing an envelope signal representing the envelope of said guitar sound signal, and sound synthesizing means (36) responsive to said sound source signal from said voltage/frequency converting means and to said envelope signal for modulating said sound source signal with said envelope signal for synthesizing a synthesized guitar tone, wherein said envelope signal providing means (31) comprises signal dividing means having first and second output terminals, said signal dividing means being responsive to said guitar sound signal for providing at said first output terminal a sound signal of the same phase as said guitar sound signal and for providing a sound signal of the opposite phase at said second output terminal, first rectifying means including a series connection of a first capacitor and a first diode coupled between said first output terminal and a reference potential for rectifying said sound signal of the same phase, second rectifying means including a second capacitor and a second diode coupled between said second output terminal and said reference potential for rectifying said sound signal of the opposite phase, and signal adding means coupled to said first and second rectifying means for adding the rectified outputs from said first and second rectifying means, whereby a separate smoothing circuit is avoided.

A guitar synthesizer, comprising:

• a guitar portion (10) including strings stretched between a bridge and a nut and pickup means (12) associated with said strings for detecting a string vibration and providing a guitar sound signal in response to a string vibration, said guitar sound signal including a fundamental wave component and harmonics, signal source means (15) for generating a fundamental wave associated signal in response to said guitar sound signal, said fundamental wave associated signal having the frequency of said fundamental wave component included in said guitar sound signal, said signal source means for generating said fundamental wave associated signal comprising voltage controlled variable bandpass filter means (41) having a variable passband characteristic coupled to said pickup means and responsive to a control voltage for varying said passband characteristic in response to the frequencies of said guitar sound signal as a function of said control voltage, frequency/voltage converting means (42) responsive to said voltage controlled variable bandpass filter means for converting the frequency of the output of said voltage controlled variable bandpass filter means into a voltage representing the frequency of said output of said voltage controlled variable bandpass filter means (41), circuit means for applying said frequency representing voltage to said voltage controlled variable bandpass filter means (41) as said control voltage for adapting said passband characteristic of said voltage controlled variable bandpass filter means (41) to the frequency of said fundamental wave component included in said guitar sound signal, whereby said signal source means (15) is adaptively and dominantly responsive to the frequency of said fundamental wave component included in said guitar sound signal, voltage/frequency converting means (35) operatively connected to said frequency/voltage converting means (42) for providing a sound source signal having the frequency of said fundamental wave component included in said guitar sound signal, envelope signal providing means (31) responsive to said pickup means for detecting a signal envelope of said guitar sound signal and providing an envelope signal representing the envelope of said guitar sound signal, and sound synthesizing means (36) responsive to said sound source signal from said voltage/frequency converting means and to said envelope signal for modulating said sound source signal with said envelope signal for synthesizing a synthesized guitar tone, said synthesizer further comprising disabling means responsive to an abrupt variation of the frequency of said fundamental wave component included in said guitar sound signal for disabling said envelope signal providing means.

A guitar synthesizer, comprising:

• a guitar portion (10) including strings stretched between a bridge and a nut and pickup means (12) associated with said strings for detecting a string vibration and providing a guitar sound signal in response to a string vibration, said guitar sound signal including a fundamental wave component and harmonics, signal source means (15) for generating a fundamental wave associated signal in response to said guitar sound signal, said fundamental wave associated signal having the frequency of said fundamental wave component included in said guitar sound signal, said signal source means for generating said fundamental wave associated signal comprising voltage controlled variable bandpass filter means (41) having a variable passband characteristic coupled to said pickup means and responsive to a control voltage for varying said passband characteristic in response to the frequencies of said guitar sound signal as a function of said control voltage, frequency/voltage converting means (42) responsive to said voltage controlled variable bandpass filter means for converting the frequency of the output of said voltage controlled variable bandpass filter means into a voltage representing the frequency of said output of said voltage controlled variable bandpass filter means (41), circuit means for applying said frequency representing voltage to said voltage controlled variable bandpass filter means (41) as said control voltage for adapting said passband characteristic of said voltage controlled variable bandpass filter means (41) to the frequency of said fundamental wave component included in said guitar sound signal, whereby said signal source means (15) is adaptively and dominantly responsive to the frequency of said fundamental wave component included in said guitar sound signal, voltage/frequency converting means (35) operatively connected to said frequency/voltage converting means (42) for providing a sound source signal having the frequency of said fundamental wave component included in said guitar sound signal, envelope signal providing means (31) responsive to said pickup means for detecting a signal envelope of said guitar sound signal and providing an envelope signal representing the envelope of said guitar sound signal, and sound synthesizing means (36) responsive to said fundamental sound source signal from said voltage/frequency converting means and to said envelope signal for modulating said sound source signal with said envelope signal for synthesizing a synthesized guitar tone, and further comprising sweep effect enabling switch means for enabling said sound source signal to attain a sweep effect performance, and transpose circuit means responsive to said sweep effect enabling switch means for applying an increasing/decreasing output voltage to said voltage/frequency converting means for varying the output frequency of said voltage/frequency converting means.

A guitar synthesizer, comprising:

• a guitar portion (10) including strings stretched between a bridge and a nut and pickup means (12) associated with said strings for detecting a string vibration and providing a guitar sound signal in response to a string vibration, said guitar sound signal including a fundamental wave component and harmonics, signal source means (15) for generating a fundamental wave associated signal in response to said guitar sound signal, said fundamental wave associated signal having the frequency of said fundamental wave component included in said guitar sound signal, said signal source means for generating said fundamental wave associated signal comprising voltage controlled variable bandpass filter means (41) having a variable passband characteristic coupled to said pickup means and responsive to a control voltage for varying said passband characteristic in response to the frequencies of said guitar sound signal as a function of said control voltage, frequency/voltage converting means (42) responsive to said voltage controlled variable bandpass filter means for converting the frequency of the output of said voltage controlled variable bandpass filter means into a voltage representing the frequency of said output of said voltage controlled variable bandpass filter means (41), circuit means for applying said frequency representing voltage to said voltage controlled variable bandpass filter means (41) as said control voltage for adapting said passband characteristic of said voltage controlled variable bandpass filter means (41) to the frequency of said fundamental wave component included in said guitar sound signal, whereby said signal source means (15) is adaptively and dominantly responsive to the frequency of said fundamental wave component included in said guitar sound signal, voltage/frequency converting means (35) operatively connected to said frequency/voltage converting means (42) for providing a sound source signal having the frequency of said fundamental wave component included in said guitar sound signal, envelope signal providing means (31) responsive to said pickup means for detecting a signal envelope of said guitar sound signal and providing an envelope signal representing the envelope of said guitar sound signal, and sound synthesizing means (36) responsive to said sound source signal from said voltage/frequency converting means and to said envelope signal for modulating said sound source signal with said envelope signal for synthesizing a synthesized guitar tone, wherein said voltage controlled variable bandpass filter means comprises filter circuit means coupled to said pickup means and responsive to said control voltage for exhibiting at least two predetermined distinctive and selective passband characteristics selected for allowing said guitar sound signal from said pickup means to pass through one of said passband characteristics determined as a function of said control voltage, and selective controlling means responsive to said control voltage for controlling said filter circuit means for selectively allowing said guitar sound signal to pass through at least one of said passband characteristics of said filter circuit means determined as a function of said control voltage, and wherein said filter circuit means comprises at least two frequency splitting filter means each exhibiting the passband characteristics of the corresponding one of at least two frequency regions of the frequencies of said guitar sound signal, and said selective controlling means comprises selective enabling means responsive to said control voltage for selectively enabling one of said at least two frequency splitting filter means as a function of said control voltage, whereby the passband characteristics of said voltage controlled variable bandpass filter means is changed into said at least two frequency regions of the frequencies of said guitar sound signal as a function of said control voltage.