A modular synthesizer format created by PAiA and intended to be a low-cost format. The format uses a module height of 5.25" and a horizontal unit of 3", although most modules are at least 2U wide. 3.5mm jacks are used for patch cord interconnects. As originally specified by PAiA, the format called for ±18V unregulated power, with voltage regulators on each module. However, Blacet, which currently offers the largest selection of modules in this format, specifies ±15V regulated power, using the same four-pin MTA-156 connector as the MOTM format. The current PAiA 9700 series boards can be modified to use this power by bypassing the regulators.
In 2006, Synthesis Technology began offering modules in the Frac format. In addition, Cynthia and Bridechamber offer some modules in this format.