Modular synthesizer



The modular synthesizer is a type of synthesizer consisting of separate modules which must be connected by wires to create a so-called patch. These synthesizers are very flexible. Every output generates an electric current of variable voltage. All inputs expect a voltage, so that almost any combination of connections between the modules is allowed and valid.

There exist many different modules and even the modules with the same function have different inputs and output on various models. But there are some standards which manufactures followed for their range of synthesizers. Connecting synthesizers from different manufactures often requires converters however.

Some standard modules found on almost any modular synth are: Modular synthesizers were largely replaced by highly integrated keyboard synthesizers, racks of MIDI-connected gear, and samplers. However, there continues to be a loyal following of musicians and manufacturers who prefer the physically-patched approach and flexibility of traditional modulars.
 * VCO - Voltage-controlled oscillator, which will play a note in a simple waveform (most usually a square wave or a sawtooth wave, but also includes pulse waves and sine waves.
 * VCF - Voltage-controlled filter, which cuts away all sounds below (high-pass), above (low-pass) or both below and above (band-pass) a certain frequency.
 * VCA - Voltage-controlled amplifier, which controls the amplitude or overall volume.
 * Envelope generator - this circuit, on receiving a trigger pulse, produces a voltage which changes in a predictable, repeatable manner over time. It can can be triggered either manually (for example, by an electronic keyboard) or automatically (for example, by a sequencer). The envelope is most commonly used to control the volume of the sound, by routing it to the level of the VCA, and the timbre of the sound, by routing it to the VCF. This could be used to simulate the volume and timbre contour of natural decaying sounds such as a piano. The patchable structure of the synthesizer makes it possible to use the envelope generator to modulate other parameters such as the pitch of the VCO, the width of the pulse wave on the VCO and so on.  The most common form of envelope contour is the ADSR, although some electronic instruments, such as those produced by Buchla & Associates or the Wiard Synthesizer Company use the simpler AD or AR contour which can be mixed to form an ADSR envelope.
 * LFO - Low-frequency oscillator, from which the output is a low frequency waveform, most usually a sine or triangle wave, usually used as a control for some other module (for instance, to modulate the frequency of the VCO's output).
 * Ring modulator - Two audio inputs are utilized to create sum and different frequencies. This gives the sound a "robotic" quality.
 * Mixer, a module that combines multiple signals into one.
 * Sample and hold, which takes a snapshot of the input voltage on a trigger pulse and keeps it steady even when the input voltage changes.
 * Sequencer, which produces a sequence of notes, usually a music loop.
 * Slew Limiter - smooths off the peaks of voltages. This can be used to create glide or portamento between notes. Can also work as a primitive low-pass filter.

The earliest commercial modular synthesizers were developed, in parallel, by Moog modular synthesizer, and Buchla in 1963. The synthesizer broadened the spectrum of possible electronic music, which before was made via tape splicing and the theremin. ARP, Serge, and EMS versions were soon to follow. In 1976, the Japanese company Roland came out with the System 700.

Modern manufacturers of modular synthesizer hardware (alphabetical)

 * Analogue Solutions (Concussor)
 * Analogue Systems (RS Integrator)
 * Blacet Research
 * Buchla & Associates (200e)
 * Club of the knobs
 * Curetronic
 * Cyndustries (Cynthia)
 * Doepfer Musikelektronik (A-100)
 * Modcan
 * Oakley Sound Systems
 * PAiA Electronics
 * Sound Transform Systems (Serge) (Sound Transform Systems does not currently maintain a web page. Link leads to fan site w/comprehensive information on Serge synthesizer)
 * Synthesis Technology (MOTM)
 * Synthesizers.com
 * Technosaurus
 * Wiard Synthesizer Company

Computers have grown so powerful and inexpensive that software programs can realistically model the signals, sounds, and patchability of modulars very well. While potentially lacking the physical presence of oft desirable analog sound generation, real voltage manipulation, knobs, sliders, cables, and LEDs, software modular synthesizers offer the infinite variations and visual patching at a more affordable price and in a compact form factor.

Modular synthesizer software (alphabetical)

 * ARP 2600 by Arturia
 * ChucK
 * CreamwareAudio Modular III
 * Csound
 * jMax
 * MaxMSP
 * Moog Modular V by Arturia
 * pure data
 * Reaktor
 * RolloSONIC
 * SpiralSynthModular
 * SuperCollider
 * SynFactory
 * SynthMaker
 * Tassman by Applied Acoustics Systems
 * Vaz Modular

Semi modular synthesizers
A semi modular synthesizer is a mix between a modular and a non-modular synthesizer. The different modules of a semi modular synthesizer are wired together, but can be re-wired by the user. Some examples are the Moog Voyager, Anyware Instruments Semtex, the Cwejman S1 and the Korg MS-10, MS-20 and MS-50.

Hybrid modular synthesizers
Hybrid synthesizers use hardware and software combination. In alphabetical order:
 * Clavia Nord Modular and Clavia Nord Modular G2 by Clavia