Scratchy sounding CDs

My headphone rig (CAL CL-10>>Granite or Audiovalve amp>>AKG K1000) has developed a "scratchy" sound; intermittent hf distoration, almost like a badly worn record or gunked up stylus. I thought it might be a bad tube, but I swapped out the tubes. Same. Then I thought it might be the amp; so I swapped out the amp. Same. Could it be the CDP? Its an oldie but I love to fill it w/5 disks and put it on full random while I am at the computer working. So I swapped in another CDP. Yep that's it. Any thoughts on what could have gone wrong? Bantam Electronics in CT is one of the folks who fix CAL, but does anyone have any idea what this might be and if its worth fixing?