Atma-Sphere logo
  • Atma-Sphere Music Systems, Inc.
  • 160 South Wheeler St. Paul, MN 55105 USA
  • Official website
  • +1 651 690 2246
  • +1 651 699 1175


Equipment[add model]

Atma-Sphere manufactures or has manufactured the following equipment (click to expand models list):

Dynamic Speakers
Valve Amplifiers

General information [contribute]

Atma Sphere web site (December 2003): We are the world's premiere OTL and triode amplifier manufacturer. Electronics for those who prefer music! All our amplifiers feature Balanced Differential Design. Balanced Differential Design is a total design philosophy. Our Circlotronic circuitry offers the simplest audio circuit path from the source to the loudspeaker. The year 2003 is our twenty-fifth year! We are the oldest manufacturer of Output TransformerLess (OTL) and triode amplifiers worldwide.

Atma-Sphere Owner's Group An independent organization, the site features a BBS, reviews, news, articles and more. To my knowledge the very first independant owner's group for a high end audio manufacturer in the world.


Atma-Sphere website (September 2000): Atma-Sphere was started in 1978 by Ralph Karsten and is the oldest manufacturer consistently producing OTL (Output TransformerLess) and triode amplifiers.

Ralph designed and patented the music producing circiut which makes our products the best in the world. Atma-Sphere's claims to fame are:

We also make unique preamps:

Forum topics on Atma-Sphere

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