Abstract: A digital audio tape recorder for processing input signals in a predetermined manner and for digitally recording the processed signals on a recording medium or reproducing digital signals recorded on the recording medium by a rotary head has a time base compressing unit and a time base expanding unit for time base compressing signals supplied to the rotary head or time base expanding signals reproduced from the rotary head for recording and reproducing data at a high transmission rate on or from the recording medium. Time base compression/expenion and the rotation of the rotary head at a number of revolutions in conformity to the high transmission rate are achieved.