Brand

Used Koss headphones

John C. Koss started his Milwaukee company in 1953 renting televisions to hospitals. In 1958 he and engineer Martin Lange Jr. built a portable stereo record player with a privacy switch for plugging in headphones, and the SP/3 that went with it is what Koss calls the world's first stereo headphone. The Pro/4 followed in 1962, the ESP/6 in 1968 as the first self-energizing electrostatic, the Pro/4AA in 1970 and the Porta Pro in 1984. Koss is famous for its Limited Lifetime Warranty, but read it before buying used. The written terms cover only the original buyer, there's a handling fee, and Koss may replace a discontinued model with a current one instead of repairing it.

5 models we cover.