[xfortrenox]

I'm pretty sure there has to be electrical current coming out of a 3.5mm jack in order for sound to come out. All the jack is doing is closing the circuit, therefore power, however minimal, is coming out of the jack. There have been very low powered add on devices, such as non-powered speakers, that used to be made for small radios and other devices of that nature. The louder the volume the more current is being put through the jack into whatever device is plugged into it. Therefore power DOES come out of the jack.