Frac rack

Frac is a modular synthesizer format. Frac is sometimes referred to as "Frac Rack". Like the Euro format, Frac is considered a 3U format. The height of most modern modular synthesizer modules is measured by the number of vertical units it consumes in a standard 19" equipment rack. Modules conforming to the 3U format, for example, will take up three vertical units in a 19" equipment rack. Frac format modules typically use 3.5mm connectors and plugs for patching, although there are several companies that offer banana jacks (BugBrand, Metalbox). Power requirements for Frac modules are typically +/-15VDC.

Manufacturers
Ad Infinitum

Analog Metropolis

Bananalogue

Blacet Research

BugBrand

Cyndustries

Encore Electronics

Future Sound Systems

Livewire

Metalbox

MOTM

Oakley Sound Systems

STG Soundlabs

Synthasonic

Wiard Synthesizer Company