Up to this point, Miller had produced only AC welders, but Miller engineers had long recognized that DC weld output produced a smoother arc. By the early 1950's, DC welders came onto the market that used a selenium rectifier to convert the AC power supplied by the utility company into DC weld output. But those first rectifiers weren't very reliable -- they were made for TV's and radios and couldn't stand up to a weld load.

Miller officials decided to manufacture their own, and in 1956, introduced the Gold Star® SR welder, utilizing a Miller-made selenium rectifier. Miller rectifiers had a failure rate of less than 1/4 of one percent - an amazing quality standard at that time. Business boomed, and almost overnight, Miller Electric became the largest selenium rectifier manufacturer in world.