In order to improve dullness of waveform of a drive signal having high slew rate necessary to jet ink droplets, which is caused by an influence of a low-pass filter formed by a resistance of a cable for connecting a power amplifier of an ink jet printer to piezo-electric heads of the printer, which are remote physically from the power amplifier, and a capacitance of the piezo-electric actuators, the ink jet printer includes intermediate circuit board 22 mounted on a carriage, control circuit board 11 having power amplifier 111 and cable 13, wherein a negative feedback loop is provided from inputs of transfer gates mounted on intermediate circuit board 12 through wiring 114 to power amplifier 111 mounted on control circuit board 11.