So I recently bought xonar u7 and whilst using it with my headphones is awesome I wanted to see if I could use it with my speakers. I'm not entirely sure what I should plug in where due to the weird plugs on my speakers. Here are some pictures I took to give you a better idea how the back of the sound card looks and what kind of plugs I'm dealing with. I was going to try using the spdif but my computer only has an optical out so I would need a converter, does that damage the sound and/or is that my only solution to this?
Sorry if I'm breaking any rules here, this is a repost from /r/audiophiles but nobody there responded. Any kind of help is greatly appreciated.