Eurorack is the most widely used modular synthesizer format. Dieter Doepfer introduced it in 1995 with his A-100 system, and it has since grown into a market with many manufacturers.
Eurorack modules mount on rails in a case. Panels are 3U tall (128.5 mm), and their width is measured in HP. Modules connect with 3.5 mm patch cables and take power from a supply that provides +12 V, -12 V, and often +5 V. Because the format is shared, modules from different makers can be combined in one case.
