released their PS range of semi-modular polyphonic instruments and their MS range of semi-modular monophonic keyboards.

Modular synthesizers have also been distributed in DIY kit form since 1972, when PAiA Electronics released the first of several DIY modular systems, the 2700 and 2720. By 1973, the Serge synthesizer was developed by Serge Tcherepnin, Rich Gold and Randy Cohen