I am experiencing same issue in my system as well. When first connected, everything was great for about a year. Then I began to have the same experience as the OP has been having with the Volume Control.
Over the next few months the issue persisted and started to include the symptoms that Charles1dad described ".. poor L/R channel balance when the Volume Control is severely restricted to the very low positions." In fact I can only achieve L/R channel balance when the Volume Control is at the 5 o' clock position.
I have sent both the CDP/DAC and Pre to their respective manufactures who swear, and I have confirmed, that they are working perfectly fine on their own. When connected - problems. I thought that the problem might be the potentiometer on the Pre -TKD 2CP2511-MC/100K. Would changing this out resolve the issue? Any suggestion that may help the OP and myself would be appreciated.
Over the next few months the issue persisted and started to include the symptoms that Charles1dad described ".. poor L/R channel balance when the Volume Control is severely restricted to the very low positions." In fact I can only achieve L/R channel balance when the Volume Control is at the 5 o' clock position.
I have sent both the CDP/DAC and Pre to their respective manufactures who swear, and I have confirmed, that they are working perfectly fine on their own. When connected - problems. I thought that the problem might be the potentiometer on the Pre -TKD 2CP2511-MC/100K. Would changing this out resolve the issue? Any suggestion that may help the OP and myself would be appreciated.