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
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
Introducing: Koss Official Standard and Oversized Colored Cushions for Porta Pro
Looking to give your Koss Porta Pro® a fresh new look? Now you can personalize your favorite headphones with official Koss Standard and Oversized Cushions, designed for comfort, style, and the perf... more
Porta Pro Utility: Connect to Anything
SHOP PORTA PRO UTILITY The acclaimed Koss Porta Pro continues to be one of the most popular headphones around the world and Porta Pro Utility takes things even further by adding the power of Koss... more