To establish the level of the digital pulse from an analog signal after conversion system, it is required a digital modulation system with fast and reliable bit rate in every bit build digital stream. Delta modulation is the commonly sufficient technique to produce a long bit stream with a relatively low bit rate. However, one of its weaknesses is that analog input signals as reference signals require a large offset frequency then obtaining small dynamic range so that the resulting noise shape has not maximal; when its sample of rate (SOR) is raised, the floor noise level cannot be controlled. This research aims to study Delta Sigma Modulation concept that has been tested to suppress the noise floor and a good form noise shape while having a stable dynamic range. This basic research will emphasize the comparison of these two forms of digital modulation and their utilization in more effective for signal conversion systems. The results show comparison of noise transfer function (NTF) mean of Delta-Sigma Modulation power spectrum decreased to 10 dB below from Delta-Modulation. Validation of simulation results through frequency spectrum comparison shows that Delta-Sigma Modulation has better noise shaping where noise floor can be easily nulled at position around the desired data channel.