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 (1/8") connectors and plugs for patching, although there are several companies that offer banana jacks (BugBrand, Metalbox).

Manufacturers
Ad Infinitum

Analog Metropolis

Bananalogue

Blacet Research

BugBrand

Cyndustries

Encore

FutureSoundSystems

Livewire

Metalbox

MOTM

Oakley

STG Soundlabs

Synthasonic-MFOS

Wiard