Hello, I have had this issue with my LuxPower SNA5000 and an Onkyo receiver. It was suggested to me that I make use of a https://www.apc.com/za/en/product/LE1200I/liner-1200va-automatic-voltage-regulator-230v-emea/. I have since purchased a unit and theoretically, it makes sense that it should work, however, I still need to repair my receiver and test it out. I was concerned about potential noise but this unit is fairly silent except when the inverter switches between mains and battery and then there is some noise for a brief moment.