I would use a HumX to safely lift the ground on the CD player.
https://www.musiciansfriend.com/accessories/ebtech-hum-x-hum-exterminator/150452000000000?cntry=US&cur=USD&source=3WWRWXGS&gclid=CjwKCAiArIH_BRB2EiwALfbH1K6ykXemTzgNJvS--eC7o0tXROx2fCxP7g2t5fY23ti5t-BBIfBuFBoCPE4QAvD_BwE
https://www.musiciansfriend.com/accessories/ebtech-hum-x-hum-exterminator/150452000000000?cntry=US&cur=USD&source=3WWRWXGS&gclid=CjwKCAiArIH_BRB2EiwALfbH1K6ykXemTzgNJvS--eC7o0tXROx2fCxP7g2t5fY23ti5t-BBIfBuFBoCPE4QAvD_BwE