Scratchy Volume Control for Analog

This is strange and I admit that I haven't spent hours traking it down, but maybe someone's run into the same thing. I have a turntable and a cd player plugged into my integrated. On the input with the turntable, the volume control on the integrated sounds scratchy when I turn it back and forth, but if I plug the cd player into the same input, the noise is gone and the noise moves to the input with the turntable. There is no noise while I'm playing records - just when I move the volume up and down like when you turn them to clean the controls. How can this be?
It could be DC on the potentiometer. If you're using a phono pre-amp (or your turntable has one built-in) it could be outputting some dc voltage which can make the pot sound dirty when it is moving. You may need some fresh caps in the phono pre. I suppose it is also possible that there is a voltage differential between the chassis of your turntable and your integrated that is putting some dc in the circuitry.
Without more info on the components in your system, I can only guess. The problem seems to follow whatever input you use for a TT. I would start there. The first thing I would do is check the settings on your phono preamp. Too much gain will cause all kinds of problems. Its very common to have a high output MC phono cart and use it with regular MC settings on your phono preamp. If you do have a high output MC cart, you will probably need to use it on the MM setting, even though you don't have a MM cart.

Aside from that, something may be broken. A soldier connection that is starting to fail can make the noise you hear. I would start replacing components, one at a time until you isolate the one that is causing the problem. Start with cables first, just because they are the easiest and go from there. You should be able to figure it out it this way.