Abstract: Monitoring the performance of recording channels during the write mode is accomplished by available read preamplifier circuitry, and a write monitor channel. During the read mode, the read preamplifier functions conventionally. During the write mode, the write signal is attenuated and monitored. The monitor circuit senses failures in the write operation and can detect the absence of write current transitions. Isolation between the non-selected channels and the selected channel is effectively provided. A detection circuit is coupled to the preamplfier for detecting electrical shorts in the magnetic heads and wiring.