Newbie to DAC's

Okay, so I have not moved into the world of DAC's. I still rely on my Marantz CD Player for my best sound. However, like everyone, I own a laptop with 2 hard drives of music. I am looking for some suggestions on how i can use my IPOD or PC to play through a vintage Pioneer SX-780 and speakers(did not buy new monitors yet). Please Help an older guy understand how this can be done on a modest budget.

Thank you!