hi everyone i've built myself a sequencer for my synth (little phatty) using an arduino mega. it's an analog (sort of) sequencer that outputs voltage from 0 to 5 v. everything works perfectly exept for when i hook up the seq to the synth. The phattys leds start flickering and moving by them selves and weird stuff happens. but this only happens when the mega is powered by a transformer, because if i power it using a usb cable everything works perfectly. googling i found out that the synth behaves weird due to a ground loop. (i had to google what a ground loop was) anyways i can't find a way to power the arduino using the ac to dc transformer . i thought of hacking a usb cable into a power cable but i'm not completely sure it is a good idea, plus i think i've read somewhere that the usb port on the arduino can only feed the board 5 volts or so, thus not enough for the arduinos needs (7-12 volts), and the last thing i would need is an arduino running low on electricity (it has 36 outputs to feed!). can anyone please help me? it is only my first project so i might even be missing something very obvious..and it is also the first time i use the forum, so please tell me if i'm doing something wrong.