ground loop issue bluetooth receiver

Hello everyone I am using a project about a Bluetooth speaker that I saw on the channel and I wanted to adapt the idea to my own project I am reviving an old Philip CD player including a Bluetooth receiver I was able to get it to work but it has this annoying noise ground or noise I used a small ground loop isolator, exactly this one that I show in the photo from the video on the channel and I had no success separating the 5V signal from the power of the Philip equipment board to the isolator And then to the Bluetooth receiver and then the Bluetooth receiver sends the audio signal directly to the RCAs of the equipment. It works I listen to the music but it has this background noise impossible to enjoy the songs.