Apple Developer Connection. The primary source for technical and business resources and information for anyone developing for Apple’s software and hardware platforms anywhere in the world. It includes programs, products, and services and a website filled with up-to-date technical documentation for existing and emerging Apple technologies. (2) Analog-to-digital converter. Circuitry that converts analog signals to corresponding digital code using sampling and quantization. ADCs are characterized by sample rate, amplitude resolution in terms of bit depth, quantization error and other distortion characteristics, and noise floor. Professional audio work usually employs ADCs with a linear response. Compare DAC. See also quantization, sample.