Yes, you can replace it. It's called a Transformer
. It's actually a coil
. They do go bad. Yours looks like it's one of the smaller ones that fit in power adapters.
Take a look here:http://www.radioshack.com/search/index.jsp...CatId=&pg=1
I'm not sure, but this transformer you should ask about:NXG NX-70VTR 70-Volt Line-Matching Transformer
As far as your wire goes... that's the RCA wire I was talking about. All you need to do is cut off one end of the wire, and replace it with the 1/8" plug that fits into the back of your computer, and you'll be good to go.
I didn't mention it before, but you'll also want to get a "Y" adapter
. That will allow you to plug your sub, and your computer speakers up at the same time.
adapter and the "Transformer"
will cost you probably around $20 or less for both. Although you may have some spare transformers lying around, I'm not going to get into salvaging any. Plus you'll need to know the correct amperages, and so forth.
But, your setup is exactly as I thought it would be. Worse comes to worst, you'll need to contact that speaker company to get a replacement transformer.
If you go to Radio Shack, take your speaker circuit board with you. By the way, that circuit board is your amplifier, or a pre-amplifier.