Using the example of the spectrometer based on acousto-optical (AO) cell with jump phase manipulation developed at the Scientific and Technological Center of Unique Instrumentation of the Russian Academy of Sciences, the possibility of creating a new class of instruments, i.e. differential AO spectrometers with arbitrary addressing working in real time, is shown. In the paper it is calculated how the error value determining the maximum position changes when the position of the combined peaks changes, as well as the dependence of this error on the peak width and height.