Since 1999, the year of establishment, Digital & Analog Co., Ltd. (also know as D&A) has been providing class D I. C.s to various audio OEM companies. And D&A started to make its own high-end audio products since 2008. As a result, they succeeded to build audio products with excellent measured performance which any other amplifiers were not able to reach so far. Calyx is the by-product of such an effort based on D&A’s many experiences like designing, manufacturing and selling of class-D IC’s and supporting its customers to make their audio products using D&A’s I.C.s. Calyx has been tested subjectively as well as objectively under a lot of test circumstances.