Hello, i have an old sony stereo sound system with a 2rca port and i want to connect it to my new Samsung tv that has only optical and hdmi ports. I also want to buy an android tv box in the future and i have seen thay many dont have an optical port but they do have av. I would probably need to. Connect the speakers to the tv box from where i will watch content so how will that work? Do i need a DAC to. Make it work with my system? (Also i found some 3rca to 3.5 cables will they work with the 2rca port? )Thanks in advance!