Rosac Electronics was a short-lived guitar effects company based in Bakersfield, California, formed in 1969 from the partnership of Morris Rosenberg and Ben Sacco — the company name being a contraction of their surnames. The brand grew out of an earlier venture, Sierra Electronics, which had been founded by Rosenberg, Sacco, and trumpet player Ralph Scaffidi together with Ed Sanner, the engineer who had designed the original Mosrite Fuzzrite. After a trademark dispute forced Sierra to abandon its name, the operation rebranded as Rosac and continued producing fuzz pedals derived from Sanner's circuits.

The company's two best-known products are the Nu-Fuzz and the Nu-Wa Fuzz. The Nu-Fuzz was a silicon-transistor variation on Sanner's Fuzzrite, replacing the depth control with a tone filter to produce a sharper, mid-forward voice distinct from the era's Big Muff-style fuzzes. The Nu-Wa Fuzz combined that fuzz circuit with a wah, allowing players to engage either effect independently, run them together, or pass a clean signal through. Rosac also produced a small number of guitar combo amplifiers.

Production wound down by the early 1970s and the company was no longer building pedals after that point, leaving only a modest number of original units in circulation. The Nu-Fuzz and Nu-Wa Fuzz are now collector items on the vintage market, and the circuits have inspired a number of boutique reissues and clones from other builders.

Rosac has 2 products cataloged on Equipboard, including Multi Effects Pedals and Fuzz Effects Pedals. Their gear is featured by 2 artists, with the strongest followings in Rock and Folk, World, & Country. Notable users include Dan Auerbach and Jake E. Lee.