How can I hook up an audio tuner to my computer so I can add remote speakers to it?

Question

well i really mean an amp I guess since most tuners come with an amplifier

Answer 1

Get a "Y" adapter that turns a mini headphone plug into a pair of red and white RCA connectors. Plug it into the headphone/speaker jack on the computer.

Answer 2

So you have a tuner/amp.  I still don't know if you want to play the tuner/amp through the computer speakers or if you want to play the computer audio through your tuner/amp.

To play the tuner/amp though he computer speakers all you need is a patch cord.  One end will have a 3 circuit mini plug which plugs into the computer "Line In"  The other end will have two RCA plugs, which will plug into the tuner/amp "Line Out", left and right.

To play the computer through the tuner/amp, you use the same patch cord, with the 3 circuit mini plug plugged into the "Line Out" of the computer, and the two RCA plugs plugged into the "Aux, or Line In" jacks of the tuner/amp.

The link shows what it looks like.