What was found
IN CRUISE FLIGHT, BOTH ENGINES STARTED SURGING, EMERGENCY CHECK LIST COMPLIED WITH AND RUN ON LANDING. MAINTENANCE COMPLIED WITH VISUAL INSP OF BOTH ENGINES AND N1 AND N2 CONTROL SYSTEMS, COMPLIED WITH GROUND RUN CHECK AND AFTER ABOUT FIVE MINUTES EXPERIENCED ENGINE SURGE. TROUBLESHOOTING REVEALED THE FORWARD MOUNTED DROOP AMPLIFIER TO BE AT FAULT, REPLACED AMPLIFIER AND DID A 20 MINUTE GROUND RUN AND GROUND CHECK OF BOTH AMPLIFIERS ALL SYSTEMS NORMAL.