![Eurorack Modular Synthesizer](https://upload.wikimedia.org/wikipedia/commons/e/e2/Eurorack_Modular_Synthesizer.jpg)
Eurorack is a
modular synthesizer format originally specified in 1995 by
Doepfer Musikelektronik.
It has since grown in popularity, and as of 2022 has become a dominant hardware modular synthesizer format, with over 15,000 modules available from more than 1000 different manufacturers ranging from DIY kits and boutique, cottage-industry designers to well-known, established synth mass-manufacturers like
Moog and
Roland.
Compact size,
3.5mm mono jacks and cables for patching all signals, and lack of a visual or sonic aesthetic defined by one manufacturer sets Eurorack apart from other modular synthesizer formats, and these factors have contributed to the popularity of Eurorack among both manufacturers and musicians.
History
![Doepfer A-100](https://upload.wikimedia.org/wikipedia/commons/6/66/Doepfer_A-100.jpg)
Before Eurorack, in the late 1970s, several modular systems based on the industrial “Euro” card frames appeared:
* Elektor Formant (3U or 6U x 7HP, 3.5 mm jacks, 31 pin bus, +/-15V)
* BME PM10/Axiom (3U x 8HP,
RCA/Phono jacks, 31 pin bus, +/-15V)
* The Synton 3000 (3U x 8HP,
4 mm “banana” jacks, +/-15V) was of similar format, but constructed more like a modern Eurorack synth.
By the late 1980s, these had all ceased production.
Dieter Döpfer built some Formant modules before producing his own systems. His Voice Modular System from the early 1980s was a Eurocard-based "modular" (the modules were non-patchable voice cards etc.) polyphonic synth, but the front panels look very similar to the later A100 modules.
In 1996, Doepfer Musikelektronik released the first Eurorack-format modular synthesizer system, the
Doepfer A-100
The Doepfer A-100 is an analog modular synthesizer system introduced by German audio manufacturer Doepfer in 1995. Although only 10 module types were at time of release, it currently has more than 120 modules plus several different enclosur ...
, followed by successive new series of compatible modules in 1997 and 1998.
[ In the UK, Analogue Systems had been independently developing a very similar format, with small technical differences such as the power connectors. Analogue Systems would later change their products to offer Eurorack compatibility.
In the mid 2000s, other manufacturers such as Cwejman, Make Noise Music and TipTop Audio adopted Doepfer's Eurorack format and started designing and manufacturing compatible modules.
By 2013, the Eurorack format had gained in popularity. Music technology journalists estimated that there were already at least 80 manufacturers offering over 700 modules, greatly expanding the musical possibilities available from a Eurorack system to include sampling and sample manipulation, West-coast-style wavefolding, DSP-based effects and more.
In the mid 2010s, increasing interest in Eurorack modulars prompted large, well-known music technology manufacturers to start producing Eurorack-compatible equipment aimed at this new market. In addition to modules, manufacturers like ]Arturia
Arturia is a French electronics company founded in 1999 and based in Grenoble, France. The company designs and manufactures audio interfaces and electronic musical instruments, including software synthesizers, drum machines, analog synthesize ...
started producing outboard devices such as the Beatstep and Microbrute
designed to be able to communicate with Eurorack modular synthesizers via 3.5mm jacks transmitting control voltages. In 2015 Moog released the Mother 32, a Eurorack-compatible semi-modular synthesizer.
By the end of fall 2018, the ModularGrid website included more than 316 manufacturers.
Specifications
For synthesizers, ''Eurorack'' is a de facto standard to allow different modules to fit in the same cases and communicate among themselves. The basic requirement is compatibility with the Doepfer technical specifications:
* Mechanical: ''A100 Construction Details''
* Electrical: ''A100 Technical Details''
Physical
The physical specification is based on the Eurocard standard of:
* 3U (5.06 inches or 128.5 mm), where height "U" is measured in rack units, rounded for a lip (nb: 3U in standard rack units would be 5.25 inches or 133.3 mm).
* 1HP (0.2 inches or 5.08 mm), where width "HP" is measured in horizontal pitch
Horizontal pitch (HP) is a unit of length defined by the Eurocard printed circuit board standard used to measure the horizontal width of rack mounted electronic equipment, similar to the rack unit (U) used to measure vertical heights of rack mou ...
units. A card width is generally integer multiples of 1HP, although some manufactures work in multiples of 0.5HP.
Eurorack modules may be further characterized by depth: shallow modules (2.5 cm to 4 c
can fit into "skiff" cases and are casually referred to as "skiff friendly".
Electrical
The Eurorack electrical specification defines a common bipolar 12V DC power bus (+12V, 0V, -12V). This can be distributed by one of two connectors with a standard 2.54 mm (0.1 in) Pin header, pitch:
* 10-pin ribbon cable, with +12V, ground, and -12V pins
* 16-pin ribbon cable, with Gate, CV, +5V, +12V, ground, and -12V pins
Audio and control signals are exchanged between modules via 3.5mm mono jack cables. The electrical characteristics of signals are split into three loosely defined categories:
* ''Audio signals'' are typically a maximum of 10V peak-to-peak (i.e. between -5V and +5V)
* ''Control voltage
CV/gate (an abbreviation of ''control voltage/gate'') is an analog method of controlling synthesizers, drum machines, and similar equipment with external sequencers. The control voltage typically controls pitch and the gate signal controls note ...
s'' can either be unipolar or bipolar. Bipolar control voltages are typically 5V peak-to-peak (i.e. from -2.5V to +2.5V), unipolar voltages between 0V and 8V. The V/Octave scale is used for pitch information
* ''Trigger, Gate or Clock signals'' are digital 0V to 5V pulses typically used for timing and event signalling.
1U Modules
Several manufacturers offer Eurorack-compatible modules in a smaller 1U tall format, sometimes referred to as "tiles". As of 2018 there are two competing standards for 1U modules, differing mainly in their height. 1U modules manufactured by Intellijel are 39.65mm high, whereas 1U modules manufactured by Pulp Logic and other manufacturers are 43.2mm high. Pulp Logic also proposes a more compact power connector for 1U modules, consisting of only three pins.
Module types
Voltage-Controlled Oscillators (VCOs)
The most common source of sound in any modular synthesizer is a Voltage-Controlled Oscillator. They depend on a Control Voltage, a lot of times routed from external hardware (for example, an analog synthesizer with a CV output, or MIDI signals processed on a MIDI-to-CV converter), to both control pitch, and output different waveforms.
There are various Control Voltage standards for determining the Voltage/Pitch relationship. The most popular ones are (1) Volts-per-octave, where 1 V equals one octave, and (2) Hertz-per-Volt, where each octave equals doubling or halving the voltage.
Noise Source
They still under the category of source modules, these modules are responsible for producing different “types” of noises (or colors
Color (American English) or colour (British English) is the visual perceptual property deriving from the spectrum of light interacting with the photoreceptor cells of the eyes. Color categories and physical specifications of color are associa ...
). They can output (1) white noise — where all frequencies in the spectrum are equally powered, (2) pink noise — where there is more power to the lower end, due to its logarithmic nature, (3) brown noise — similar to pink noise, but steeper slope, (4) blue noise — oversimplified, the opposite of the pink noise, with more power concentrated on the higher frequencies, among others.
Modulators
Under the category of processors, modulators will modify an incoming signal. The effects produced are widely varied and a lot of times, modules will be built for a specific function, for example:
* LFOs (Low-Frequency Oscillators) will produce a inaudible frequency (usually below 20Hz), that will be used to modulate the VCO, and produce a vibrato-like effect by varying the pitch.
* Tremolos will affect the loudness of a signal producing a similar effect of the LFOs.
Filters
Another kind of processor, filters are modules shaping the sound by attenuating specific frequency ranges. These modules will contain all or a selection of the following: (1) a high-pass filter (where anything above a certain frequency can “pass”), (2) a low-pass filter (anything below a given frequency can pass), (3) a band-pass filter (where anything “in between” two frequencies can pass), and (4) a notch filter (where one cuts a specific range of frequencies out allowing everything else to pass).
Sequencers
Essentially, modules that can both operate as a source or a processor of musical content in the form of CV or MIDI messages. The most common kind are step-sequencers, where each individual musical event is triggered in a “step” of a bigger sequence (or loop).
Utilities
Utility modules are the ones responsible for expanding certain capabilities of a specific setup. They can be used to combine, split, divide, multiply, quantize, or offset a signal. One example of a utility module is a multiplier, that allow one to send any CV output to many other inputs. Another example are the attenuators responsible for scaling the CV signal with a control knob (much like faders in a mixing console).
Effects
A lot similar to the concept in a guitar pedal, effects modules are used to change the sound of an incoming signal. They can be (1) dynamic processors, used to control the level of a signal (like compressors, or limiters), (2) equalizers, used to change the frequency characteristics of a given sound (sometimes in the form of a eurorack mixer module), or (3) special effects, like delays, reverbs, or choruses.
DIY and open source
The technical and modular nature of Eurorack often attracts people who are interested in modifying or building their own modules or cases. Many Eurorack manufacturers started off as individuals building " do it yourself" (DIY) modules or offering DIY kits before expanding into production. Building DIY modules can be a gateway to learning more about electronics and physical manufacturing, as well as being satisfying and developing a more intimate connection with the synthesizer as a personal musical instrument.
Some manufacturers such as Befaco, Bastl Instruments and Erica Synths offer some or all of their modules both as assembled products or as kits to be assembled by the buyer. Doepfer
Doepfer Musikelektronik GmbH is a German manufacturer of audio hardware, mostly synthesizer modules (modular synthesizer), based in Gräfelfing, Upper Bavaria and founded by Dieter Döpfer. The product range covers analog circuit, analog modular s ...
offers a case and power supply kit, as well as 'low cost' cases designed to be customised and finished by the buyer.
Releasing modules exclusively as open source designs and DIY kits allows designers such as Music Thing Modular to design and release popular modules such as the Turing Machine or Radio Music without having to run a company or invest in manufacturing. Open Source licenses for both hardware and code allow individuals to build the modules from scratch, and companies such as Thonk to offer kits.
Some manufacturers do not offer kits or intend for end users to build their products, but release the code, schematics and layout under open source licenses. Émilie Gillet of Mutable Instruments cites transparency and the possibility for customers to customise or modify their modules as driving reasons for this decision.
Notable users
* Alessandro Cortini
Alessandro Cortini (born 24 May 1976) is an Italian musician best known for being the keyboard, guitar, and bass player in the industrial band Nine Inch Nails. Cortini is also the frontman for the Los Angeles-based electronic-alternative band ...
* Andrew Huang
* Aphex Twin
* Beirut
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* Blush Response
* BT
* Celldweller
Celldweller is an American electronic rock project by multi-musician Klayton. Celldweller songs have been featured in many films, movie trailers, television shows and video games.
Career Precursors: Circle of Dust and Angeldust (1992–1999)
Th ...
* Coldplay
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* Covenant
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Religion
* Covenant (religion), a formal alliance or agreement made by God with a religious community or with humanity in general
** Covenant (biblical), in the Hebrew Bible
** Covenant in Mormonism, a sacred agreement b ...
* Daedelus
* Deadmau5
Joel Thomas Zimmerman (born January 5, 1981), known professionally as Deadmau5 (stylized as deadmau5; pronounced "dead-mouse"), is a Canadian electronic music producer and DJ. He mainly produces progressive house music, though he also produce ...
* Depeche Mode
* Emily A. Sprague (Florist
Floristry is the production, commerce, and trade in flowers. It encompasses flower care and handling, floral design and arrangement, merchandising, production, display and flower delivery. Wholesale florists sell bulk flowers and related sup ...
)
* Erika M. Anderson (EMA)
* Rayna Russom
Rayna Kirilova Terziyska ( Bulgarian:Райна Кирилова Терзийска) is a Bulgarian pop-folk singer and singer of traditional music. Rayna was born on 30 September 1981 in Sandanski
Sandanski ( bg, Сандански ; el, Σ ...
* Geologist
A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, earth science, or geophysics, althoug ...
( Animal Collective)
*Jake Williams
Jake Williams (born 1974) is a British electronic music producer and remixer, who currently records as Rex the Dog. Rex the Dog currently releases on Kompakt Records. As Rex the Dog, Williams is a proponent of DIY electronics and performs liv ...
* JunkieXL
* Kaitlyn Aurelia Smith
* Keith Fullerton Whitman
Keith Fullerton Whitman (born May 29, 1973) is an American electronic musician who has recorded albums influenced by many genres, including ambient music, drill and bass, and krautrock. He records and performs using many aliases, of which the ...
* Kyteman
* Lady Starlight
* Luke Abbott
Luke Abbott is an English electronic music producer from Norwich, Norfolk. He records and performs extensively under his own name, under the alias Earlham Mystics and as one third of electronic jazz group Szun Waves. His work has been describe ...
* Martin Gore
Martin Lee Gore (born 23 July 1961) is an English songwriter, musician, singer, record producer and DJ. He is one of the founding members of the electronic rock band Depeche Mode and is the band's main songwriter. He is the band's guitarist a ...
* Nine Inch Nails
* Orphx
Orphx is a Canadian music duo made up of Rich Oddie and Christina Sealey who perform techno, industrial and experimental music. They have performed worldwide and have numerous releases on CD, vinyl and cassette through independent music labels ...
* Richard Devine
Richard Devine is an Atlanta-based electronic musician and sound designer. He is recognized for producing a layered and heavily processed sound, combining influences from glitch music to old and modern electronic music. Devine largely records for ...
* Robert Aiki Aubrey Lowe
* Surgeon
* The Blow
The Blow is an American electro pop band, comprising Khaela Maricich and Melissa Dyne. Maricich and Dyne write, compose, produce and perform all the music. It was formed as a solo project by Maricich in 2002, and she was joined by Jona Bechtol ...
* Venetian Snares
Aaron Funk (born January 11, 1975), known as Venetian Snares, is a Canadian electronic musician based in Winnipeg, Manitoba. He is widely known for innovating and popularising the breakcore genre, and is one of the most recognisable artists to b ...
See also
* List of synthesizer manufacturers
Notable synthesizer manufacturers past and present include:
{{div col, colwidth=33em
A
* Access Music
* Alesis
* ARP
* Arturia
* Akai
B
* Behringer
* Buchla and Associates
C
* Casio
* Clavia
* Crumar
D
* Dave Smith Instruments ...
References
External links
{{Commons category, Eurorack
Eurorack
on Synth DIY wiki
Eurorack Rails DIY Guide
ModularGrid
— an interactive database of modules and manufacturers
Modular synthesizers