hey, it isn't always a good idea if the voltage is lower, the device might not start then
and, it may depend on the particular device but my 720 can take a higher voltage, even 14.6 V instead of 12... i didn't intend to give it that much voltage, those universal adapter are just crappy
(luckily i acquired an original adapter since then
). also that's why you can go a little lower with the nominal voltage, as it will still put out a voltage that's high enough. for example my universal crap puts out 12V when its at the 9V setting..
so don't go for universal ones! buy one that can put out only one amount of voltage!