As soon as I plug in a standard 3.5mm jack cable into my speaker AUX IN port they produce a loud disturbing noise exactly as this one: https://en.wikipedia.org/wiki/File:MainsBrum50Hz.ogg. I don't even need to connect a cable to a computer, it's enough for it to be connected to speakers only. My speakers are Creative Inspire S2 Wireless. When I turn up volume, humming is louder. I tried connecting a power supply to another wall outlet, turning off my router but it didn't help. My current guess is that power adaptor is broken. I could get a new one where I live for a couple of dollars. It's worth mentioning that Bluetooth connectivity works completely fine, there is no humming when a device is connected to the speakers that way.
Does it make sense to get a new power adapter in such case?