To provide a rotary magnetic head device with which control states of plural MR heads and recording heads mounted on a rotating drum can be switched with high speed.

Plural MR heads (301-312) are configured with a single-chip head assembly, plural recording heads (201-206) are configured with the single-chip head assembly, and characteristics variations for each of the heads are therefore suppressed. Head switching data for recording and reproducing circuits (401-406), bias current setup data for each of the MR heads and record current setup data for each of the recording heads are transmitted as an identical value. This enables the transmitted data, required for the head switching, to be sufficient with one kind for recording and reproducing, respectively, and the transmitted data can be transmitted within a shortest period of time.