So I have an LG TV and a really old Panasonic unit that controls sound plugged into two even older speakers (50+ years old!). The Panasonic uses RCA input and then I run speaker wire to the speakers. I have a optical to RCA converter. The audio works great if I am using a device that I connect to the TV through an HDMI cord such as my PS4. But if I use the smart TV apps, I get loud buzzing. Any ideas on how to fix?