Telecommunications technology specifically in the transmission of electromagnetic signals is needed efficiency, and good quality. Digital signal transmission is able to fulfill this, namely an efficient system and good quality. An information signal in the form of an analog or continuous signal cannot be transmitted with a digital system, it must be processed first, namely changing the analog signal to a digital signal before being transmitted digitally. Therefore we need a tool that can convert analog signals into digital signals, namely the Analog to Digital conversion system (ADC). Desain build digital modulator systems, namely: Delta Modulation, this system will use the prediction modulation method or approach between the information signal and the comparative signal in the form of a step ladder. The output signal is logic 1 when the information is greater than the step ladder, and logic 0 when the information signal is smaller than the step ladder signal. Step ladder is good for Delta Modulation when the sampling frequency is high, with high sampling the noise reduction will appear. Digital transmission can serve high speed transmission. Digital systems have a signal regeneration process, ( a system that generates pulse signals at the same receiver as the transmitted / transmitted signal) so that the system becomes reliable. Delta modulation will generate bits / pulses from analog signals. Delta Modulation forms several circuit blocks, namely differential amplifiers, comparators, clock and pulse generators, integrators and low pass filters. Delta modulator circuit will display the signal change process simply. Generate an A / D and D / A system, which is the prototype of the Delta Modulation system.