In ink jet system printers of charge amplitude controlling types ink drops issuing from a nozzle and rapidly traveling in their path toward a record receiving member are subjected to air resistances. Particularly the individual charged ink drops serving for printing purposes are under influences of air resistances which are different in accordance with the presence and absence of preceding charged ink drops and such differences result in faulty printing.In order to minimize the occurrence of distortions in the recording as described above the control system disclosed herein produces correction signals in accordance with the conditions of presence charged and absence of the preceding ink drops to adjust the amplitude of charges on the individual ink drops, thereby obviating the distortions in the recording due to the air resistances.