Get the full report on the classic Koss Pro4AA Stereophone, from audiophile writer Steve Guttenberg:
CNET - Back to the Future: Koss Pro4AA headphones
Blog posts
History: The Koss SP/3X
In 1958, John C. Koss invented personal listening with the World’s First SP/3 Stereophone. Koss sought to replicate the excitement of a live musical performance and the original SP/3 stereophone al... more
Headphone School: The World's First Koss SP/3 Stereophone That Started It All
In 1958, John C. Koss invented personal listening with the world’s first SP/3 Stereophone. Koss sought to replicate the excitement of a live musical performance and teamed up with engineer Martin L... more
Koss Clear Transparent Headphones
Explore the wide range of clear and transparent headphones from Koss in both Over ear and On ear including KPH30i Clear, Porta Pro Utility, CL/80, CL-20, CL-5 and CL-2. Shop Now more