A data storage device is disclosed comprising a head actuated over a magnetic media, wherein the head comprises a write element and a first read element. A preamp circuit comprising an interface includes at least a write line associated with the write element of the head and a first read line associated with the first read element of the head. A first read signal is received from the preamp circuit over the first read line during a read operation, and configuration data is transmitted to the preamp circuit over the first read line during a write operation.