PURPOSE: To prevent an error rate of a reproduced PCM signal from being deteriorated by applying AC bias recording of a QDPSK signal to a depth of a magnetic tape and recording a video signal to an upper layer of the magnetic tape.
CONSTITUTION: The VTR is provided with a band pass filter 34 limiting the band of a bit string DQ from a 2/4 conversion circuit 33 and outputting a QDPSK signal SQ and an oscillation circuit 38 for an AC bias signal SB. The QDPSK signal SQ is fed to 1st rotary magnetic heads 1A, 1B together with an AC bias signal SB to apply AC bias recording to an upper layer part and a depth of a magnetic tape 4, a video signal SV is fed to 3nd rotary magnetic heads 2A, 2B to record the video signal SV to the upper layer while erasing the QDPSK signal SQ at the upper layer part. Since the signal is converted by the 2/4 conversion circuit in a pure digital way, the phase of a carrier signal of an 0-QDPSK signal is not fluctuated due to temperature. Thus, the deterioration in the error rate of the reproduced PCM signal DR is prevented.