I’m currently trying to figure out the amperage or (ah) / wattage of my system. I have been adding up all the dc. Now I have a fender guitar amplifier that takes 40 watts and 120 volts to get going. I used the formula 40w/120v=0.33a, which seems like a very low draw for such a big piece of equipment. I also have a music mixer that runs on 16 Watts and it can run from 100volt to 240volts, together they would draw about 1 amp according to my calculations. so then I wonder Is it less or more draw to run a larger inverter rather than a smaller inverter? I’d like to use both at the same time if I could, how can I do it most efficiently?