How do I get my audio from my laptop to a PA system.?

How do I go from either HDMI/3.5mmheadphone/optical cables to a PA system using speakon/1/4in/XLR cables. I really dont want to pay for an expensive mixer. I would prefer just some sort of box that converts the audio without any bells or whistles. I run my HDMI into my TV and an optical out into my surround sounds but I want to do some DJing and surround sounds arent exactly portable or reliable. What will give me the best quality. Feel free to elaborate.