A modular synthesizer format developed by Bruce Duncan's Modcan company and used by its A series modules. (Modcan also makes a B series which uses the MOTM format.) The Modcan-A format uses a module height of 9", and a horizontal unit of 2.25". Banana jacks are used for all patch cord interconnects. A unique convention of the format is the use of jacks with different color surrounds to indicate the general function of the jack: in general, a yellow jack indicates an output of some sort; a gray jack is a signal input; a white jack indicates a control voltage input; and a red jack is a trigger or gate input. Because the banana jack patch cords do not carry a signal return conductor, modules which have inputs or outputs intended to be connected to other equipment are equipped with 1/4" phone jacks; there is also an interface module which provides two-way conversion between phone and banana jacks.
The format calls for ±15V power. The power connector used is a 3-pin MTA-156 connector; the means of connecting modules is similar to the MOTM format, in which a distribution board connected to the power supply is connected to modules using short power cords with female connectors on both ends. Adaptor cords are available, or easily made, which allow powering the modules from an MOTM power board.
The other major manufacturer of Modcan-A modules, besides Modcan itself, is Cynthia.