RY13, RY11 and RY10 RY13 The fail-safe signal from the reproduce amplifier in use is connected through the contacts of changeover relay RY13 to the input of the failsafe amplifier. the presence of the fail-safe signal on the channel selected for connection to the reproduce amplifier indicates that the recording/ reproducing cycle is functioning normally. RY11 The output signal from the fail-safe amplifier energizes failsafe relay RY11. RY11 also outputs -20vdc to RY13 which in turn outputs -20vdc to light the safe light. RY10 RY11 energizes holding relay RY10. In the event that the failsafe signal fails to appear at the output of the failsafe amp, the FAILURE indicator lights and the alarm is sounded automatic changeover is accomplished with the loss of the failsafe signal.