Modular synthesizer

A modular synthesizer is an electronic musical instrumentconsisting of various modules that can be connected to each other to create and modulate sounds. Complex sound generation and manipulation can be realized through the flexible patch connection of the modules.

Structure and technology

There are modules for sound generation (e.g. VCO), modules for sound modification (e.g. VCF) and modules for control (e.g. ADSR). The individual modules are connected to each other via cables (patch cables) or switches, sometimes also via sliders and patch panels. For a given number of modules with inputs and outputs, there are therefore a large number of connection options. The final signal is usually output via a loudspeaker or forwarded to a recording device.

A key feature of analog modular synthesizers is the voltage control of individual parameters of a module. The control voltage (CV) can be generated by a keyboard or a sequencer, for example, and applied to the CV input of the VCO, whereby a change in the voltage causes a change in the generated frequency. Other important parameters are the filter cut-off frequency of the VCF or the gain of the VCA, which in conventional patches are usually controlled via the ADSR (often also called EG for “envelope generator”). The control voltage range of 0 to 10 volts introduced by Moog has become the industry standard.

An exponential curve of the control voltage is also used to control the VCO and VCF, which leads to a doubling of the frequency per volt. There are also deviating control voltage standards, e.g. at KORG (MS-10, MS-20, MS-50 etc.) or Yamaha. Eurorack also has modules that operate in the range from -5V to +5V at both the output and input. With some of these modules, the voltage range can be switched between -5V to +5V and 0 to +10V, mainly via jumpers on the rear panel, and with many modules also via the digital configuration, e.g. with some MIDI-to-CV/Gate modules.

Other control voltages are referred to as “gate” and “trigger” and do not cause a continuous change in the parameter, but are used to switch events. The gate signal influences the duration of the event by keeping the parameter switched for a certain time. This duration can, for example, be the time a key is pressed on the keyboard. The trigger signal is a pulse of the same duration that triggers a signal once without influencing the rest of the process. This can be, for example, the start parameter of a sequencer, which starts its function independently after a single “trigger”. These control voltages are usually generated by a change from 0 volts to 5 volts.

Modules

Modular synthesizers are complex electronic musical instruments that consist of a large number of basic elements. These include voltage-controlled oscillation generators (VCO), amplifiers (VCA), filters (VCF), phase shifters (VCP) and low-frequency oscillators (LFO). Envelope generators (ADSR), sample-and-hold modules, noise generators, mixers, crossfaders, sequencers, wavefolding and modulator modules as well as wavetable synthesizers and dynamic range compressors (DRC) are also important. The diverse possibilities for patching and connecting these modules allow musicians and sound designers to create unique soundscapes.

To give modular synthesizers a structured form, the individual modules are often mounted in racks. These racks usually conform to the 19-inch standard and offer a practical way to organize and connect the modules. However, modular synthesizers also offer the flexibility to combine and customize different modules to achieve the desired sound and functions. Although theoretically any module that can handle voltages can be used in a modular synthesizer, modules designed specifically for these instruments are often used. The result is a fascinating combination of electronic creativity and musical freedom.

Creative work with modular synthesizers

Live performance and improvisation:
Immerse yourself in the exciting world of live performance and improvisation with modular synthesizers. Use the variety of modules to create unique soundscapes in real time and enrich your performance with improvisational elements. The flexible patching options allow you to experiment spontaneously and keep discovering new sounds that will fascinate your audience.

Sound design for music productions and film scores:

Give free rein to your creativity and design individual soundscapes for music productions and film scores. Modular synthesizers offer an incredible range of sound generation possibilities, allowing you to create bespoke sounds. Whether atmospheric textures, captivating effects or striking leads – the flexibility and versatility of the modules allows you to shape the sound exactly as you want it, giving your musical works a very special touch.

List of well-known modular synthesizers

• Moog Modular: Known for its warm and full sound, the Moog Modular was used by artists such as Emerson, Lake and Palmer.
• Roland System 100M: A modular system from Roland that was popular in the 1970s and offered versatile sound generation possibilities.
• Roland System 700: A larger and more complex modular system from Rolandwhich was known for its flexibility and variety of sounds.
• E-Mu Modular: A modular system from E-Mu Systems that has been appreciated for its high sound quality and extensive modulation possibilities.
• ARP 2500: A modular system from ARP Instruments that was used by many musicians and bands of the 1970s, including well-known artists such as Stevie Wonder and Herbie Hancock.
• EMS Synthi 100 and Synthi AKS: Modular systems from Electronic Music Studios (EMS) that were known for their unique sound characteristics and creative patch possibilities.
• Buchla modules: Buchla Electronic Musical Instruments produced a variety of modules that were prized for their experimental and avant-garde sound production.
• Formant: A modular synthesizer that became known as a DIY project. The building instructions were published in the electronics magazine “Elektor” in the 1970s and provided amateur musicians and beginners with an affordable alternative to commercial systems.

Although some of these modular synthesizers are no longer produced today, they have had a significant influence on the development of electronic music and are firmly anchored in the history of music.