hi, just a quick one, my car stereo stopped working the other night so i have been using my kaboom with a dc-ac inverter ie turns 12v into mains, works ok but there is an audiable hum through the speakers (only slight) doesnt do it when its on real mains.

could this do any damage do you think or should it be ok?

It has more to to with feedback noise from the electrical system of your car.

The cigarette lighter and inverter are unfiltered. Your car stereo has a noise filter for the power supply for sure.

Most Kabooms have a DC input that will work from a car cigar-lighter 12V socket. Maybe try that?

when I had my GF-777 booming on the back seat of my mate's car, it was plugged into an inverter. The Sharp made a slight humming, but it was fine.