Hardware Sound card question

Hey, its been a while since I last posted on this site. Upgraded my computer like crazy, but now I have a question before I finish what is left to be done.
My sound card is a built in one, so it can’t be taken out. But thats ok, because even if I wanted to use another, I know how to disable it. I also got a new 500 watt power supply, and that is where the problem comes from. My new power supply works great and all, its just it didn’t come with a cord that fits my sounds card. The plug it has for a sound card is different and a bit larger.
So my first question is, is there such a thing as a adapter to change the plug style so it will fit?
If not, what are some recomendations to get sound going again (I may just have to buy a new sound card, though I don’t like spending any more money since it was already alot).