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Digitally-controlled Oscillator
A digitally controlled oscillator or DCO is used in synthesizers, microcontrollers, and software-defined radios. The name is analogous with "voltage-controlled oscillator." DCOs were designed to overcome the tuning stability limitations of early VCO designs. Confusion over terminology The term "digitally controlled oscillator" has been used to describe the combination of a voltage-controlled oscillator driven by a control signal from a digital-to-analog converter, and is also sometimes used to describe numerically controlled oscillators. This article refers specifically to the DCOs used in many synthesizers of the 1980s . These include the Roland Juno-6, Juno-60, Juno-106, JX-3P, JX-8P, and JX-10, the Elka Synthex, the Korg Poly-61, the Oberheim Matrix-6, some instruments by Akai and Kawai, and the recent Prophet '08 and its successor Rev2 by Dave Smith Instruments. Relation to earlier VCO designs Many voltage-controlled oscillators for electronic music are based on a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Synthesizer
A synthesizer (also spelled synthesiser) is an electronic musical instrument that generates audio signals. Synthesizers typically create sounds by generating waveforms through methods including subtractive synthesis, additive synthesis and frequency modulation synthesis. These sounds may be altered by components such as filters, which cut or boost frequencies; envelopes, which control articulation, or how notes begin and end; and low-frequency oscillators, which modulate parameters such as pitch, volume, or filter characteristics affecting timbre. Synthesizers are typically played with keyboards or controlled by sequencers, software or other instruments, and may be synchronized to other equipment via MIDI. Synthesizer-like instruments emerged in the United States in the mid-20th century with instruments such as the RCA Mark II, which was controlled with punch cards and used hundreds of vacuum tubes. The Moog synthesizer, developed by Robert Moog and first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Kawai
is a musical instrument manufacturing company headquartered in Hamamatsu, Shizuoka, Japan. It is best known for its grand pianos, upright pianos, digital pianos, electronic keyboards and electronic synthesizers. The company was founded in August 1927. History Koichi Kawai, the company founder, was born in Hamamatsu, Japan in 1886. His neighbor, Torakusu Yamaha, a watchmaker and reed organ builder, took him in as an apprentice. Kawai became a member of the research and development team that introduced pianos to Japan. Yamaha died in 1916, and in the 1920s the piano industry faltered in Japan. New management took over control of Yamaha's company, Nippon Gakki Co. (later renamed the Yamaha Corporation), and began to diversify its production line. This led Kawai to leave Nippon Gakki in 1927 and found the Kawai Musical Instrument Research Laboratory. After Koichi Kawai's death in 1955, his son, Shigeru Kawai became company president at 33 and expanded production facilities. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Microprocessor
A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circuitry required to perform the functions of a computer's central processing unit. The integrated circuit is capable of interpreting and executing program instructions and performing arithmetic operations. The microprocessor is a multipurpose, Clock signal, clock-driven, Processor register, register-based, digital integrated circuit that accepts binary code, binary data as input, processes it according to instruction (computing), instructions stored in its computer memory, memory, and provides results (also in binary form) as output. Microprocessors contain both combinational logic and sequential logic, sequential digital logic, and operate on numbers and symbols represented in the binary number system. The integration of a whole CPU onto a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Electronic Organ
An electric organ, also known as electronic organ, is an electronic keyboard instrument which was derived from the harmonium, pipe organ and theatre organ. Originally designed to imitate their sound, or orchestral sounds, it has since developed into several types of instruments: * Hammond-style organs used in pop, rock and jazz; * digital church organs, which imitate pipe organs and are used primarily in churches; * other types including combo organs, home organs, and software organs. History Predecessors ;Harmonium The immediate predecessor of the electronic organ was the harmonium, or reed organ, an instrument that was common in homes and small churches in the late 19th and early 20th centuries. In a fashion not totally unlike that of pipe organs, reed organs generate sound by forcing air over a set of reeds by means of a bellows, usually operated by constantly pumping a set of pedals. While reed organs have limited tonal quality, they are small, inexpensive, se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Frequency Division
A frequency divider, also called a clock divider or scaler or prescaler, is a circuit that takes an input signal of a frequency, f_, and generates an output signal of a frequency: : f_ = \frac where n is an integer. Phase-locked loop frequency synthesizers make use of frequency dividers to generate a frequency that is a multiple of a reference frequency. Frequency dividers can be implemented for both analog and digital applications. Analog Analog frequency dividers are less common and used only at very high frequencies. Digital dividers implemented in modern IC technologies can work up to tens of GHz. Regenerative A regenerative frequency divider, also known as a Miller frequency divider, mixes the input signal with the feedback signal from the mixer. The feedback signal is f_/2. This produces sum and difference frequencies f_/2, 3f_/2 at the output of the mixer. A low pass filter removes the higher frequency and the f_/2 frequency is amplified and fed back into mixer. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Jupiter 8
The Jupiter-8, or JP-8, is an eight-voice polyphonic analog subtractive synthesizer introduced by Roland Corporation in early 1981. The Jupiter-8 was Roland's flagship synthesizer for the first half of the 1980s. Approximately 3300 units have been produced. Although it lacked the soon-to-be standard of MIDI control, later production series of the Jupiter-8 did include Roland's proprietary DCB interface. The instrument had many advanced features for its time, including the ability to split the keyboard into two zones, with separate patches active on each zone. Two years after the release of the Jupiter-8, Roland released the more affordable Jupiter-6 synthesizer with built-in MIDI control but an otherwise slightly reduced set of features. In 2011, three decades after the release of the original Jupiter series, Roland released the fully digital Jupiter-80 and Jupiter-50 synthesizers as successors to the 1980s originals. They were in turn succeeded by the Jupiter-X and Jupite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Yamaha CS-80
The Yamaha CS-80 is an analog synthesizer released in 1977. It supports true 8-voice polyphony, with two independent synthesizer layers per voice each with its own set of front panel controls, in addition to a number of hardwired preset voice settings and four parameter settings stores based on banks of subminiature potentiometers (rather than the digital programmable presets the Prophet-5 would sport soon after). It has exceptionally complete performer expression features, such as a layered keyboard that was both velocity-sensitive (like a piano's) and pressure-sensitive (" after-touch") but unlike most modern keyboards the aftertouch could be applied to individual voices rather than in common, and a ribbon controller allowing for polyphonic pitch-bends and glissandos. Production of the instrument ceased in 1980. Vying with the Sequential Circuits Prophet-5 and Oberheim OB-X polysynths for the title, the CS-80 is often described as the pre-eminent polyphonic analog synthesize ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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8253
The Intel 8253 and 8254 are programmable interval timers (PITs), which perform timing and counting functions using three 16-bit counters. The 825x family was primarily designed for the Intel 8080/ 8085-processors, but were later used in x86 compatible systems. The 825x chips, or an equivalent circuit embedded in a larger chip, are found in all IBM PC compatibles and Soviet computers like the Vector-06C. In PC compatibles, Timer Channel 0 is assigned to IRQ-0 (the highest priority hardware interrupt). Timer Channel 1 is assigned to DRAM refresh (at least in early models before the 80386). Timer Channel 2 is assigned to the PC speaker. The Intel 82c54 (c for CMOS logic) variant handles up to 10 MHz clock signals. History The 8253 is described in the 1980 Intel "Component Data Catalog" publication. The 8254, described as a superset of the 8253 with higher clock speed ratings, has a "preliminary" data sheet in the 1982 Intel "Component Data Catalog". The 8254 is impleme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Sawtooth Wave
The sawtooth wave (or saw wave) is a kind of non-sinusoidal waveform. It is so named based on its resemblance to the teeth of a plain-toothed saw with a zero rake angle. A single sawtooth, or an intermittently triggered sawtooth, is called a ramp waveform. The convention is that a sawtooth wave ramps upward and then sharply drops. In a reverse (or inverse) sawtooth wave, the wave ramps downward and then sharply rises. It can also be considered the extreme case of an asymmetric triangle wave. The equivalent piecewise linear functions x(t) = t - \lfloor t \rfloor x(t) = t \bmod 1 based on the floor function of time ''t'' is an example of a sawtooth wave with period 1. A more general form, in the range −1 to 1, and with period ''p'', is 2\left( - \left\lfloor + \right\rfloor\right) This sawtooth function has the same phase as the sine function. While a square wave is constructed from only odd harmonics, a sawtooth wave's sound is harsh and clear and its spectrum con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Comparator
In electronics, a comparator is a device that compares two voltages or currents and outputs a digital signal indicating which is larger. It has two analog input terminals V_+ and V_- and one binary digital output V_\text. The output is ideally : V_\text = \begin 1, & \textV_+ > V_-, \\ 0, & \textV_+ < V_-. \end A comparator consists of a specialized high- . They are commonly used in devices that measure and digitize analog signals, such as s (ADCs), as well as [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Operational Amplifier Applications
This article illustrates some typical operational amplifier applications. A non-ideal operational amplifier's equivalent circuit has a finite input impedance, a non-zero output impedance, and a finite gain. A real op-amp has a number of non-ideal features as shown in the diagram, but here a simplified schematic notation is used, many details such as device selection and power supply connections are not shown. Operational amplifiers are optimised for use with negative feedback, and this article discusses only negative-feedback applications. When positive feedback is required, a comparator is usually more appropriate. See Comparator applications for further information. Practical considerations Operational amplifiers parameter requirements In order for a particular device to be used in an application, it must satisfy certain requirements. The operational amplifier must * have large open-loop signal gain (voltage gain of 200,000 is obtained in early integrated circuit exemplars) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Capacitor
A capacitor is a device that stores electrical energy in an electric field by virtue of accumulating electric charges on two close surfaces insulated from each other. It is a passive electronic component with two terminals. The effect of a capacitor is known as capacitance. While some capacitance exists between any two electrical conductors in proximity in a circuit, a capacitor is a component designed to add capacitance to a circuit. The capacitor was originally known as the condenser, a term still encountered in a few compound names, such as the '' condenser microphone''. The physical form and construction of practical capacitors vary widely and many types of capacitor are in common use. Most capacitors contain at least two electrical conductors often in the form of metallic plates or surfaces separated by a dielectric medium. A conductor may be a foil, thin film, sintered bead of metal, or an electrolyte. The nonconducting dielectric acts to increase the capacitor's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |