Koss
4 verified products
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Read our full verification: Is Koss Made in USA?Est. 1958
Koss has been manufacturing products in Milwaukee, WI since 1958. We carry 4 verified American-made Koss products.
The Invention of the Stereo Headphone
John C. Koss founded Koss Corporation in Milwaukee, Wisconsin in 1958, and within months introduced the SP-3 stereophone — the world's first pair of stereo headphones. Before that moment, headphones existed as telephone and radio monitoring tools, not as consumer audio devices. Koss changed the category entirely, giving listeners a way to experience recorded music with the spatial separation that stereo recordings were designed to deliver.
The technology that made it possible was Koss's Temporal Pressure Gradient driver design, which uses the interaction between the ear and the air pressure around a dynamic driver to produce a wider soundstage than conventional headphone designs. That same underlying principle drives the Porta Pro, the collapsible on-ear model that has been in continuous production since 1984 and remains one of the most-recommended headphones in any price category.
Electrostatics Made in Milwaukee
Koss's most technically ambitious products are its electrostatic headphones, the ESP-950 and ESP-95X Plus, both hand-assembled at Koss World Headquarters in Milwaukee. Electrostatic drivers use a thin charged membrane suspended between two conductive stators rather than a conventional voice coil and magnet. The result is a diaphragm so light that it can follow extremely fast transients — the attack and decay of notes — with accuracy that dynamic drivers can only approximate.
The ESP-95X Plus uses an advanced diaphragm coating and damping materials refined over decades of electrostatic development. It achieves a frequency response from 8 Hz to 35,000 Hz — well beyond the range of human hearing at both ends, but relevant to the accuracy of in-band reproduction. Each pair is assembled by hand in Milwaukee, a process that reflects the precision required to match two electrostatic panels to each other within specification.
A Milwaukee Institution
Koss has remained headquartered in Milwaukee for over sixty years, through the transformation of the audio industry from vinyl to cassette to CD to streaming. The company has held its ground on domestic manufacturing for its flagship products even as most consumer electronics production moved offshore.
The lifetime warranty that Koss introduced in 1989 — covering all North American headphone purchases indefinitely against defects and failures under normal use — remains one of the strongest commitments in consumer audio. A pair of Porta Pros purchased in 1989 can still be sent to Milwaukee for free repair or replacement today. That warranty has been honored through multiple ownership changes and market cycles, making it a credible signal of manufacturing confidence rather than a marketing pledge.
Frequently Asked Questions
Is Koss made in the USA?
Yes. Koss manufactures 4 verified products in Milwaukee, WI. Koss Corporation invented the modern stereo headphone in 1958 and has assembled its flagship electrostatic models by hand at its Milwaukee, Wisconsin headquarters ever since, earning a permanent place in the audio equipment hall of fame.
Where is Koss manufactured?
Koss is headquartered in Milwaukee, WI. Manufacturing takes place in Milwaukee, WI.
What Koss products can I buy?
We carry 4 verified Koss products across Electronics. Every listing links directly to Amazon with verified American manufacturing.
When was Koss founded?
Koss was founded in 1958. Koss Corporation invented the modern stereo headphone in 1958 and has assembled its flagship electrostatic models by hand at its Milwaukee, Wisconsin headquarters ever since, earning a permanent place in the audio equipment hall of fame.