I'll partially agree with Albertporter about conditioners as many just compress the sound.
I have not tried regenerators such as PS Audio so I can't comment on them.
I have used transformers in isolation and balanced setups that have given mixed results from worse to better. As isolation only and properly sized, they have not been any worse. Typically, a small isolation transformer would supply the CDP as backflow protection, in plumbing terms.
If you got noise coming from the speakers when the music stops, isolation might be the simple answer. Unfortunately, the problem may be more complex.
I have not tried regenerators such as PS Audio so I can't comment on them.
I have used transformers in isolation and balanced setups that have given mixed results from worse to better. As isolation only and properly sized, they have not been any worse. Typically, a small isolation transformer would supply the CDP as backflow protection, in plumbing terms.
If you got noise coming from the speakers when the music stops, isolation might be the simple answer. Unfortunately, the problem may be more complex.