Hi, I am running this amp with 2x 10" Boston subs. Every now and then the amp will stop playing music, and I can hear a popping sound. It is as if the amp is turning on and off a lot. This will happen at any time, hot or cold, amp running a while or when first turned on. Turning it off does not always stop it when turned back on. The volume has not effect either. I have moved the amp to a different position in the system running different speaker, different power connections and different RCA cable & input. But the same problem happens. I have changed the trigger wire and internal relay,both made no difference. Can anyone suggest where to look next? All other amps in the system are working correctly.