I’ve been using my Bose Companion 2 Series II speakers for years with no problem. I recently moved and when I plugged the speakers in, there is a very noticeable high-pitched whine coming from the speakers. It’s not constant, it’s sounds like feedback of some sort, but it’s not in any sort of patterned way. Turning the volume up or down doesn’t change anything about the whine and brining it close to other electronics also doesn’t seem to change anything. I plugged them into different outlets around the apartment and some have less of the pulsing whine than others, but it’s always still there. Unfortunately the one area that I need the speakers for is the worst. Any suggestions? The AC adaptor is a replacement, is there any chance that could be a reason? Thanks for any and all help.
Since this started happening after you moved into the new apartment and it varies depending on the outlet used I'd suspect an electrical issue within the suite or the building itself. I would take your speakers to a friend or relatives place and see if the issue continues there. I also wouldn't rule out the possibility the replacement adaptor is faulty or poorly made. It could be picking up electrical interference that wasn't present in your previous residence. As its easier to replace the adaptor than move, see if you can get a new adaptor from Bose. Someone from here from Bose or a Bose retailer can likely help you with that.
Thank you for taking the time to post and welcome to the Community!
I'm sorry to hear of the issues you are experiencing with your Companion 2 speakers I'll be happy to help you!
I think is on the right lines, as your whining sound varies dependant on the outlet, I think you could be suffering from some kind of interference.
I would recommend testing the system with your electrical devices switched off to see if this improves, better still, as suggested by , take it to a friend or families house to test.