Abstract: An electronic musical instrument having fewer note generators than notes stores in a sequentially addressable memory different waveform segments corresponding to different sounds. The note generators are time multiplexed by a processor, and use end addresses of current waveform segments to determine whether each current sample to be read is within the desired waveform segment. This limits the ability to noiselessly and rapidly move between segments. It is accommodated by storing a copy of the waveform segments in a readily shifted direction for immediate playout and subsequent shift to the destination waveform segment while reading the copy. This allows for cluster switching and scanning of waveform cycles to control a modulation of the base note, such as attack or tremulant, independently of the base note pitch.

Abstract: An electronic musical instrument has a plurality of oscillators. Each oscillator reads out segments of a waveform stored in memory using a random selection method. In one method the loop or start address is selected at random and the selection of a new address may be one cycle from the loop address or may be a repeat of the prior end address. In another method, both the loop and end addresses are randomly selected. Further, the end address is repeated a number of times determined randomly within a defined range of numbers.

Abstract: A mathematical function-generating device for producing, in an electronic musical instrument, functional values from an accumulation of first digital data. A digital data-generating circuit generates first digital data. A digital value string-generating circuit generates a bit-reversed digital value which increments a predetermined amount each time a first digital data unit is generated and which corresponds to a predetermined number of least significant bits in said first digital data unit. An adder is provided for adding the first digital data to a digital value comprising an accumulated value truncated to a predetermined number of least significant bits and having the bit reversed digital data concatenated thereto, thereby producing a new accumulated value. A memory is provided for storing and truncating each new accumulated value. The memory also supplies the adder with the new accumulated value.

Abstract: A stereophonic electronic organ system having two electrical-acoustic channels each including a loudspeaker separated from the other, note generating means for producing for each note in a musical range two time-displaced electrical signals of substantially the same frequency corresponding to the note, and means for coupling one of the two signals for each note to one of the channels and means for coupling the other of the two signals to the other of the two channels. The two time-displaced signals for each note may be produced by providing two digital tone generators for each note and time-displacing one note from the other.

Abstract: An electronic system for controlling the speed of a shaded-pole single-phase induction motor provides increased power during speed increase and automatic braking during slowdown by regulation of half-wave D.C. braking current applied to the motor.Speed control during normal operation, and braking control during slowdown and stopping, are implemented by means of dual feedback loops interactively connected to the gate electrode of a triac in the A.C. current line of the motor. The speed control loop utilizes a frequency/phase detector to adjust the time delay of triac gating relative to the zero crossing points of each half-cycle of A.C. voltage until the tachometer-sensed speed of the motor corresponds to a desired speed set by a voltage controlled oscillator. The braking control loop adjusts the time delay of the triac gating relative to the zero crossing points of every alternate half-cycle of A.C. power thus decelerating the motor by an impressed half-wave pulsed D.C. current.

Abstract: An improved mounting for an acoustic pulsato rotor for suppression of spurious sounds utilizes a spring bias for axial thrust between the shaft ends and bearing cups. In one form, a plurality of thin spider legs extend from a rotor mounting panel in surrounding relationship to the rotor to provide the spring characteristics while being acoustically transparent to the sound radiation pattern that sweeps past. The spider legs have a quick fit, anti-noise twist lock connection to a central hub. Improved rubber-like grommets provide anti-shock and anti-noise mounting for the shaft. Improved rubber-like grommets in cooperation with a two part motor mounting provide anti-shock and anti-noise motor mounting without sacrifice of simple belt tension adjustment capability. A light weight back enclosure for the speaker acquires sound isolation characteristics of a sturdy structure by imposing stress on the enclosure.

Abstract: A signal animation system for an electric organ or other electrical musical instrument which utilizes frequency-proportional detuning wherein the percentage detuning is progressive and uniform, to provide celeste and other musical effects. Detuning is accomplished by a shift register through which sampled electrical representations of an input tone signal are shifted progressively through the register from the input to the output, which delays the signal. The trigger pulses which time the shifting function are frequency-modulated in a manner such that the period of the trigger pulses, rather than their frequency is proportional to a control voltage supplied to the trigger pulse generator.