Not sure if this is in the right forum or not, so if it isn't, could a mod please move it.

I have an old Technics SA-GX390 (I think its an amp) and I am wondering if it would be possible to use that to hook up to my computer if I add some speakers from an old home hifi setup?

The object is to be able to play music etc through my computer with much better than tinny computer speakers.

Obviously the idea is to do this on the sub$ cheapo.

I would have no idea how to set it up as I have never used an amp before.

Is it possible or is this SA-GX390 the wrong type of equipment?