Waveform synthesis for an electronic musical instrument
AssigneeThe Wurlitzer Company
InventorsGeorge S. Klaiber, Anthony C. Ippolito, William R. Hoskinson
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Abstract
A plurality of rectangular waves of selected duty cycles and fundamental frequencies are generated. Selected ones of these waveforms are then added at selected amplitude ratios. Such additions provide resultant waveforms of desired fundamental frequencies and having desired harmonic contents or spectra, for simulating the characteristic sounds of acoustical musical instruments.
Claims10
In an electronic musical instrument, a first bus having a nominal footage B and carrying first rectangular waves of 50% duty cycle, a second bus having a nominal footage of 1/2B and carrying second rectangular waves of 50% duty cycle, output means, and means for combining said first and second waves as rectangular waves at relative amplitudes A and about 0.707A to said output means to produce an output wave with a harmonic spectrum of a 25% duty cycle rectangular wave of footage B.
Apparatus for producing a waveform comprising means providing a first 50% duty cycle rectangular wave of frequency f and relative amplitude A, means for providing a second 50% duty cycle rectangular wave of frequency 2f and amplitude 0.707A, and means for adding said first and second waves to produce a resultant wave, said resultant wave having the harmonic spectrum of a 25% duty cycle rectangular wave of frequency f.
The method of synthesizing a waveform which comprises providing a first 50% duty cycle rectangular wave of frequency f and amplitude A, providing a second 50% duty cycle rectangular wave of frequency 2f and relative amplitude about 0.707A, and adding said first and second waves to produce a resultant output wave with the harmonic spectrum of a 25% duty cycle rectangular wave at frequency f.
Dependencies are inferred from the claim text.