Chasmal,
A sporadic problem like this points to the need for a holistic approach, first ruling out something further down the chain, like a driver or preamp tube, oxidized RCA connector or bad voice coil. If everything is fine with line-level/CD playback (meaning no noticeable distortions or problems), then move on to the LP chain.
Doug's responses regarding phono chain diagnosis are spot on. My only comment would be that if one uses a cartridge with a somewhat exotic stylus profile, (like the Dorian), alignment becomes extremely crucial. Check, double check and check again. Remember, not all protractors are created equal, and you may have difficulties trying to implement a Baerwald alignment on a Rega, which favors a Stephenson alignment. Also, since you're using an LP12, I would recheck your arm cable dressing through the P-clip. Any hang or drag on the arm cable will cause grief, and can certainly result in the type of distortions you are hearing. The Linn can be funny that way...while you're at it, double check suspension set-up and make sure the platter is level.
-Richard
A sporadic problem like this points to the need for a holistic approach, first ruling out something further down the chain, like a driver or preamp tube, oxidized RCA connector or bad voice coil. If everything is fine with line-level/CD playback (meaning no noticeable distortions or problems), then move on to the LP chain.
Doug's responses regarding phono chain diagnosis are spot on. My only comment would be that if one uses a cartridge with a somewhat exotic stylus profile, (like the Dorian), alignment becomes extremely crucial. Check, double check and check again. Remember, not all protractors are created equal, and you may have difficulties trying to implement a Baerwald alignment on a Rega, which favors a Stephenson alignment. Also, since you're using an LP12, I would recheck your arm cable dressing through the P-clip. Any hang or drag on the arm cable will cause grief, and can certainly result in the type of distortions you are hearing. The Linn can be funny that way...while you're at it, double check suspension set-up and make sure the platter is level.
-Richard