High pitched noise Roland KR-5000

I have a Roland KR-5000 that makes a high pitched noise which gets louder as I turn the volume up. It’s in the speakers and headphones (both)

Very occasionally it stops but not often.

Reminds of a sound I get with my MacBook which only stops if I unplug the charger and just run the battery. This sound on my Roland doesn’t sound like a connection or bad wire analog audio issue. Thoughts???