@agharion "I get the rumble when the turntable is not in use."
You've got me confused. Until now I thought the thread was completely about rumble while playing LPs. Here's a line from your original post: "As soon as a signal was passed from the phono, the sub went crazy, it produced some subsonic noise that made the room shake. I then connected the phono to a tube integrated amp and I heard a loud distorted noise through my LS 3/5A."
So, I'm not sure where you go from here. You've got a ton of suggestions so guess you just keep experimenting. Have you brought in a different phono preamp to find if the issue is still present?

