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