Quote: The only thing I have connected to the card is the Sennheiser 558s.   Edit: Well this is strange. I had done a little research and was preparing to order a ground loop isolator from Amazon. I wasn't sure whether it would solve the problem or not, since most of the situations...

I recently bought a Xonar DGX soundcard to accompany my Sennheiser 558s, and they seemed to be working well for the most part, but now the DGX is emitting a strong, constant humming sound. I don't think it was there for the first few hours or so of testing, because it's so loud that I can't...