PURPOSE:To eliminate the drum assembly interchangeablity noise by transmitting the reproduced and demodulated sound signal through a filter circuit having the comb-shaped chracteristics that produce a bottom part in response to a frequency of an integer multiple as much as the switching frequency of a rotary magnetic head. CONSTITUTION:The drum assembly interchangeability noise nDA having the periodical performance is contained in the sound signal SA obtained by a changeover switch 16. The noise nDA is produced in response to the switching of heads HA and HB and has a frequency of an integer multiple as much as the switching frequency fS. The sound signal SA is supplied to a filter circuit 17 which has the comb-shaped characteristics that produce a bottom part at bands less than 1-2Hz and in response to the frequency of an integer multiple as much as the frequency fS of the heads HA and HB. Therefore the signal SA containing no noise nDA is obtained from an adder 19.
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