Modular synthesis has grown in popularity over the past few years. The flexibility of a modular system allows for the creation of complex and dynamic sounds that aren’t achievable on most subtractive synthesizers. However, the flexibility can also add confusion. Below are some common questions that beginners might have when exploring modular synthesis with the SYSTEM-1m PLUG-OUT Synthesizer, SYSTEM-500 Modular Series and AIRA modules.
What is a Modular Synthesizer?
As the name suggests, modular synthesizers are made up of individual modules that each perform a limited number of specific tasks. An individual module does little or nothing on its own. They must be patched together using cables in order for them to perform a complete function that produces a sound.

What is a Semi-Modular Synthesizer?
A semi-modular synthesizer is pre-wired internally so that no patching is required in order to create sounds. However, patch points are provided to extend the capabilities of the synth. When patching takes place, the signals are either mixed or the default wiring is disconnected internally.
What is Eurorack?
The most widely used modular format is called Eurorack. It outlines the physical sizes allowed for modules, as well as power specifications.

SYR-E84 Eurorack for modular synthRoland SYR-E84 Eurorack Case

What is Control Voltage?
One of the signals sent over patch cables are called Control Voltage (CV). It is a voltage that allows one module to control another. For example, the pitch of an oscillator module will increase as the CV is increased at its input.

CV is often used for voltage controlled oscillators (VCO), voltage controlled filters (VCF) and voltage controlled amplifiers (VCA). Common module types that generate CV include MIDI to CV converters, low frequency oscillators (LFO) and envelope generators (EG).

What is Gate and Trigger?
A gate is a signal where the voltage goes high when a note is played, and then returns to zero after the note is released.  A trigger is similar, but returns to zero immediately after the initial rise in voltage – it does nothing when the note is released.
What is a Clock?
A clock is an on and off pulse. It is used to sync modules together. Since the pulse is any voltage signal that goes from low to high, a square wave LFO is often used to create a clock signal.

A common example of where a clock is used is with a sequencer. Each pulse in the clock signal advances the sequencer by one step. If the same clock is sent to a second sequencer, then both will advance at the same time.



  Jacob Watters is the Synth & DJ Product Sales Specialist for Roland Canada.