Atma-Sphere

About Atma-Sphere

Atma-Sphere, founded in 1978 and based in Saint Paul, MN, is renowned for pioneering and producing world-class vacuum tube amplifiers, especially Output TransformerLess (OTL) and triode designs. Under the leadership of Ralph Karsten, the company has introduced multiple industry firsts, including the first reliable and practical OTL amplifiers, balanced-line preamps, and fully differential zero-feedback tube amplifiers. All Atma-Sphere products are hand-crafted, often custom optioned, and use proprietary components to deliver unmatched reliability and a uniquely transparent musical experience, upholding the highest standards for high-end audio systems.