A digital-to-analog converter performs a ΔΣ computation process to start the ΔΣ computation based upon the second clock signal with respect to the digital data of music sound if the ΔΣ computation is not under execution when the control signal is outputted by the signal output process, a control process to inhibit the ΔΣ computation based upon the second clock signal from being started with respect to the digital data of music sound until the ΔΣ computation is not under execution when the ΔΣ computation is under execution, and an output process to convert a computation result of the ΔΣ computation process into an analog signal and output the analog signal.