Frequency modulation synthesis is a form of sound synthesis whereby the frequency of a waveform is changed by modulating its frequency with a modulator. The (instantaneous) frequency of an oscillator is altered in accordance with the amplitude of a modulating signal.
Pulse-width modulation (PWM), also known as pulse-duration modulation (PDM) or pulse-length modulation (PLM), is a method of controlling the average power or amplitude delivered by an electrical signal. The average value of voltage fed to the load is controlled by switching the supply between 0 and 100% at a rate faster than it takes the load to change significantly. The longer the switch is on, the higher the total power supplied to the load. Along with maximum power point tracking (MPPT), it is one of the primary methods of controlling the output of solar panels to that which can be utilized by a battery. PWM is particularly suited for running inertial loads such as motors, which are not as easily affected by this discrete switching. The goal of PWM is to control a load; however, the PWM switching frequency must be selected carefully in order to smoothly do so.
Wavetable synthesis is a sound synthesis technique used to create quasi-periodic waveforms often used in the production of musical tones or notes.
The MOS Technology 6581/8580 SID is the built-in programmable sound generator chip of the Commodore CBM-II, Commodore 64, Commodore 128, and MAX Machine home computers.
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.
Ensoniq ESQ-1 is a 61-key, velocity sensitive, eight-note polyphonic and multitimbral synthesizer released by Ensoniq in 1985. It was marketed as a "digital wave synthesizer" but was an early Music Workstation. Although its voice generation is typically subtractive in much the same fashion as most analog synthesizers that preceded it, its oscillators are neither voltage nor "digitally controlled", but true digital oscillators, provided by a custom Ensoniq wavetable chip. The signal path includes analog resonant low-pass filters and an analog amplifier.
Phase distortion (PD) synthesis is a synthesis method introduced in 1984 by Casio in its CZ range of synthesizers. In outline, it is similar to phase modulation synthesis as championed by Yamaha Corporation, in the sense that both methods dynamically change the harmonic content of a carrier waveform by influence of another waveform (modulator) in the time domain. However, the application and results of the two methods are quite distinct.
Direct digital synthesis (DDS) is a method employed by frequency synthesizers used for creating arbitrary waveforms from a single, fixed-frequency reference clock. DDS is used in applications such as signal generation, local oscillators in communication systems, function generators, mixers, modulators, sound synthesizers and as part of a digital phase-locked loop.
The Korg OASYS is a workstation synthesizer released in early 2005, 1 year after the successful Korg Triton Extreme. Unlike the Triton series, the OASYS uses a custom Linux operating system that was designed to be arbitrarily expandable via software updates, with its functionality limited only by the PC-like hardware.
The microKORG is a MIDI-capable digital synthesizer/vocoder from Korg featuring DSP-based analog modelling. The synthesizer is built in such a way that it is essentially a Korg MS-2000 with a programmable step arpeggiator, a less advanced vocoder, lack of motion sequencing, lack of an XLR microphone input, and in a smaller case with fewer real-time control knobs.
The Korg DW-8000 synthesizer is an eight-voice polyphonic hybrid digital-analog synthesizer 61-note keyboard instrument released in 1985. By the time of its launch, Korg had already begun a common trend in 1980s synthesizer design: using numerical codes to access or change parameters with its predecessor - the Korg Poly-61, which was widely regarded as the company's first "knobless" synthesizer. This was a move away from the heavily laden, complex control panels of earlier designs.
The Korg Wavestation is a vector synthesis synthesizer first produced in the early 1990s and later re-released as a software synthesizer in 2004. Its primary innovation was Wave Sequencing, a method of multi-timbral sound generation in which different PCM waveform data are played successively, resulting in continuously evolving sounds. The Wavestation's "Advanced Vector Synthesis" sound architecture resembled early vector synths such as the Sequential Circuits Prophet VS.
Linear arithmetic synthesis, or LAsynthesis, is a means of sound synthesis invented by the Roland Corporation when they released their D-50 synthesizer in 1987.
The Roland JD-990 Super JD is a module version of Roland JD-800 synthesizer with expanded capabilities, which was released in 1993. JD-990 is a multitimbral synthesizer utilizing 'wave-table' sample-based synthesis technology. It is equipped with 6 MB of ROM containing sampled PCM waveforms, four sets of stereo outputs that are assignable to individual, internal, instruments, and standard MIDI in/out/through ports. JD-990 has a large LCD display and programming takes place through a keypad on the front panel of the unit. The unit can generate multi-timbral sounds reminiscent of the vintage analogue synthesizers but is also capable of generation of modern digital textures. There are several expansion boards available for JD-990 that can be installed in the provided expansion slot in the chassis of the unit.
A synthesizer 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.
A frequency synthesizer is an electronic circuit that generates a range of frequencies from a single reference frequency. Frequency synthesizers are used in many modern devices such as radio receivers, televisions, mobile telephones, radiotelephones, walkie-talkies, CB radios, cable television converter boxes, satellite receivers, and GPS systems. A frequency synthesizer may use the techniques of frequency multiplication, frequency division, direct digital synthesis, frequency mixing, and phase-locked loops to generate its frequencies. The stability and accuracy of the frequency synthesizer's output are related to the stability and accuracy of its reference frequency input. Consequently, synthesizers use stable and accurate reference frequencies, such as those provided by a crystal oscillator.
The Korg Mono/Poly (MP-4) is a 44 key "mono-polyphonic" analog synthesizer manufactured by Korg from 1981 to 1984. This keyboard is the sister synthesizer to the Korg Polysix. It has four highly stable voltage-controlled oscillators (VCOs), a 4-pole, self-oscillating low pass filter (LPF), wide modulation capabilities and pseudo-polyphony (paraphony).
The AX80 is a polyphonic analogue keyboard synthesizer manufactured by Akai Professional in 1984. It was Akai's first venture into the professional electronic musical instrument market. The AX80 used digitally controlled oscillators (DCO) and filter circuitry based on the Curtis Electronics CEM 3372 integrated circuit. It was marketed as part of a line of project studio equipment called the Akai Music Studio System, which included the S612 digital sampler the MR16 drum machine, the MS08 sequencer, and the MG1212 multitrack tape recorder, at a price of $1,695 US.
The Korg Z1 is a physical modelling sound synthesiser released in 1997. Touted as a polyphonic Prophecy, the Z1 implements 13 synthesis types, all derived from the original OASYS synthesizer.
The OPL series are a family of sound chips developed by Yamaha. The OPL series are low-cost sound chips providing FM synthesis for use in computing, music and video game applications.
