Acronym for "Moog Console Panel", an oddball module format used in some vintage Moog modular synths. The larger Moog modular synth modules had, at the bottom of the cabinet, a row for modules that were roughly half of the height of the standard Moog modules. It was originally intended as a space to mount the synth's power supply and its control panel, but Moog reasoned that the extra space could be used for utility modules. Moog produced a handful of modules that fit in the MCP space, most of which consisted of passive mixer and signal routing modules. Over the past three years, a few modular manufacturers, including Moon Modular and Club of the Knobs, have produced a few new modules in this format.
There is some controversy about what the proper dimensions of a MCP panel should be, caused by the fact that on the original Moog modulars, the console panels were mounted on a piano hinge so that they could be swiveled up away from the surface, in order to access the power supply and other components mounted behind the panels. Although the space in which the panels mount is 147 mm high, the panels themselves are 5-5/8", or 143 mm, high. This is because the piano hinges take up some of the space. Also, the mounting hole pattern on the edge of the panel that attaches to the piano hinge matches the hole pattern of the hinge, which is different from the standard MU hole pattern. Some of the current manufacturers of MCP-format modules fabricate the panel for mounting in a hinge, and some for mounting on standard MU mounting rails without a hinge. Before buying a MCP module, check to see which one it is.