My tv only has an optical out for a choice of audio out. I bought a OREI digital to analog convertor to hook up a powered speaker. I found out it does not work with digital "over the air" signals. That is my only source for tv. Please help. p.s. the convertor went from optical in to RCA out which i then used a 3.5mm audio jack into the speaker. The sound coming out of the speakers was awful digital scrambling white noise.