Get the weekly hi-fi digest — new gear, best reads, and deals.
Founded in 1953 by John C. Koss in Milwaukee, Wisconsin, Koss Corporation began as the J.C. Koss Hospital Television Rental Company when Koss used $200 intended for a sofa to purchase broken TV sets for rental to hospitals. In 1958, Koss teamed with engineer Martin Lange Jr. to develop a portable stereo phonograph player, inadvertently creating the world's first high-fidelity stereo headphones, the SP/3, which revolutionized personal audio by delivering stereo sound without speakers. The legendary Porta Pro, introduced in 1984, became one of the most iconic and enduring headphones in audio history, setting performance and comfort standards worldwide for decades. After John C. Koss passed away in December 2021 at age 91, his son Michael J. Koss, who became president and CEO in 1991, continues leading the company from their Milwaukee headquarters. In 2024, Koss celebrated the 40th anniversary of the Porta Pro with the launch of the Porta Pro Wireless, maintaining their legacy as the granddaddy of audiophile headphones. Today, Koss remains committed to their Milwaukee roots and American manufacturing heritage, continuing to innovate in personal audio technology while honoring their founder's vision of accessible high-quality sound.