A former modular synthesizer manufacturer based in Glendale California, and named after its owner, Cynthia Webster. (The company is actually named Cyndustries, but Cynthia is the brand name that appears on the products.) Cynthia got its start designing specialized modules that filled in gaps in the Modcan-A module lineup, many of them based on circuit boards from Catgirl Synth. As Modcan expanded its model line, Cynthia turned to offering a smaller lineup of specialized modules which were available in all five of the most popular formats -- Dotcom, Eurorack, Frac, Modcan-A, and MOTM. One notable product was the Zeroscillator, a VCO with through-zero modulation capability; this kicked off something of a fad for through-zero oscillators.
The company ceased doing business in 2017.