A digital signal recording apparatus includes an amble generator for generating an amble signal representing a bit-sequence amble pattern. The bit-sequence amble patter can be detected and reproduced by a partial-response detection system "PR(1, 0, -1)" as a detected amble pattern having a period of state inversions which is shorter than a period of state inversions in a detected amble pattern corresponding to a recorded amble pattern of alternation of "1" and "0". The amble signal generated by the amble generator and a first digital information signal are combined into a second digital information signal on a time sharing basis. The second digital information signal is recorded on a magnetic recording medium. For example, the bit-sequence amble pattern represented by the amble signal has repetition of six bits of "111000".