The present invention relates to a sound source device, and more particularly, it aims at providing a sound source device, in which a sufficient sound emitting quantity can be attained, capable of obtaining a reproduced sound of musically rich expression.

And, in order to attain the aforementioned object, it is possible to solve such a problem that energy density is low and sound emitting efficiency is inferior by employing a pseudo-rectangular wave increasing spectral density as waveform data input in a waveform table (TB). For this, it is rendered a spectrum including spectral Lines X1, X2, X3 and X4 in a range matching with a frequency domain (HR) having high sound emitting efficiency and including even harmonics.

A real time tone generation system for synthesis of musical instruments comprises means (51) for providing a control signal for initiating and thereafter controlling generation of a tone, connected to wave transmission means (53) via a junction (52). The junction receives signals from and passes signals to the wave transmission means, the supplied signals being a function of the control signal and the signal received from the wave transmission means. Thus, the nature of the signal propagating in the wave transmission means depends on the characteristics of the wave transmission means and the junction means and the value of the control signal.

Data of desired variable data length is stored in a memory. When desired data is to be taken out of the memory, data length of the data to be taken out is designated and necessary data is selectively taken out of the memory in accordance with the designated data length. Single data may be stored over plural addresses. In that case, MSB or LSB of data to be taken out of the data stored over the plural addresses is pointed out and desired data of a desired bit number is taken out in accordane with the pointed out position and the bit number of the data. In the memory, first data and second data may be mixedly stored. The second data consists of plural bits and is divided in plural sections, each section being separately stored in the first data. The first data and the second data are separated from the data which has been read from the memory and the respective sections of the second data are assembled together to reproduce completed second data. This storage and reproduction of data contributes to an efficient utilization of the memory.

An input waveform signal is converted into a digital peak value signal by an A/D converter (8), and the digital peak value signal is input to one input ter­minal A of a comparator (42). The other input terminal B of the comparator (42) receives a preset digital peak value signal from a memory (43). These input signals are compared by the comparator (42). The content of the memory (43) is reduced at a predetermined rate. If the comparator (42) detects that the currently input wave­form level is larger than the continuously reduced level of the memory, i.e., if A > B, a new waveform level is loaded in the memory (43). As a result, the output from the comparator is inverted. That is, condition A > B is changed into condition A < B. The timing of this change in condition serves as a peak timing of the input wave­form signal.

The present invention provides an analog signal synthesizing apparatus including a waveform memory for storing a plurality of analog signals as PCM data sampled with different sampling frequencies, the amount of PCM data corresponding to plural channels being read from the waveform memory and used to synthesize the analog signals. The analog signal synthesizing apparatus includes an oversampling device for shifting the sampling frequency of said PCM data read from said waveform memory for each channel toward the side of high frequency; a summing device for summing the oversampled PCM data for the respective channel; a D/A converter for converting the summed data into an analog signal; and a low-pass filter for setting a cut-off frequency based on the sampling frequency shifted to the side of high frequency and for eliminating aliasing noises included in the PCM data from the synthesized analog signal. The elimination of the aliasing noise included in the PCM data for each channel is carried out at the common low-pass filter.

An input waveform signal is converted into a digital peak value signal by an A/D converter (8), and the digital peak value signal is input to one input ter­minal A of a comparator (42). The other input terminal B of the comparator (42) receives a preset digital peak value signal from a memory (43). These input signals are compared by the comparator (42). The content of the memory (43) is reduced at a predetermined rate. If the comparator (42) detects that the currently input wave­form level is larger than the continuously reduced level of the memory, i.e., if A > B, a new waveform level is loaded in the memory (43). As a result, the output from the comparator is inverted. That is, condition A > B is changed into condition A < B. The timing of this change in condition serves as a peak timing of the input wave­form signal.

A global envelope is input by a user and stored in a global envelope memory (3). At the respective envelope-controlled sine wave generators (15-1 - 15-n), are generated envelope functions of the respective orders by modifying the input global envelope. The envelopes of component wave signals of a plurality of orders are independently controlled by the envelope functions having the respective orders in the genera­tors (15-1 - 15-n), and a musical tone signal is synthe­sized by combining the envelope-controlled component wave signals.

The present invention provides an analog signal synthesizing apparatus including a waveform memory for storing a plurality of analog signals as PCM data sampled with different sampling frequencies, the amount of PCM data corresponding to plural channels being read from the waveform memory and used to synthesize the analog signals. The analog signal synthesizing apparatus includes an oversampling device for shifting the sampling frequency of said PCM data read from said waveform memory for each channel toward the side of high frequency; a summing device for summing the oversampled PCM data for the respective channel; a D/A converter for converting the summed data into an analog signal; and a low-pass filter for setting a cut-off frequency based on the sampling frequency shifted to the side of high frequency and for eliminating aliasing noises included in the PCM data from the synthesized analog signal. The elimination of the aliasing noise included in the PCM data for each channel is carried out at the common low-pass filter.

Disclosed is a signal processor formed using digital waveguide networks. The digital waveguide networks have signal scattering junctions. A junction connects two waveguide sections together or terminates a waveguide. The junctions are constructed from conventional digital components such as multipliers, adders, and delay elements. The signal processor of the present invention is typically used for digital reverberation and for synthesis of reed, string or other instruments.

A programmable tone generator for an electronic musical instrument generates a pulse train output (F out) in which in each cycle the starting time and duration of each pulse is controlled, thereby to determine the harmonic content of the electronic waves that are converted to audio sound. A binary counter (12) serves as a time base for encoding each period of a tone signal waveform into plural outputs (14) in the form of a binary code. A plurality of programmable tone generation circuits (16) are coupled with selected counter outputs (14) to comprise plural tone signal branchs (16), each providing a tone signal at a selected fundamental frequency and having selected harmonic content. Each tone signal branch (16) includes a programmable variable code generator (26) and determines the initial content of the output waveform, subsequently either maintaining or changing the fundamental frequency and harmonic content thereof.

An electronic musical instrument comprizing plural keyswitches for playing music, a generator assigner scanning the plural keyswitches, sensing depression thereof and sending channel selecting data and timbre data, plural sound generating channels for generating musical sound signals in accordance with said timbre data, and a channel selector selecting said plural sound generating channels in accordance with said channel selecting data, wherein said generator assigner designates depressed keyswitch to vacant one of said plural sound generating channels and sends said channel selecting data representing said vacant channel to said channel selector.