I would like to use my L1 Compact in outdoor venues where 120VAC is not available. I would like to use a "power pack" consisting of a battery and inverter. I know there are a variety of inverter circuits which can produce anything from a square wave to a pretty accurate sine wave. Does the converter in the L1C care about the quality of the input AC sine wave? Is there a specific technical requirement on input harmonics? And, ideally, can anyone recommend a power supply that has been shown to work with the L1C?