Legit question, why would you use a receiver with a soundbar? What are you trying to achieve? Best use of a soundbar is HDMI from the TV to soundbar. I just can't understand why you would want to us an amp to another amp (powered soundbar)
RCA to Optical Converter
I have an older Onkyo TX-8050 receiver. I want to connect the speaker output (left & right, each with a red & white RCA female connector, total of 4) to my Bose soundbar. The only option I have for input on the soundbar is an optical female. How do I do this?