I have a fairly warped LP that when observed as playing causes the tonearm to seesaw a bit, affecting piano harmonics to be "watery" as this tonearm action rides the wave. Of course that was through my Dual 701 turntable which I thought was Dual's flagship in 1974.

Now I play the same warped record on my Denon DP 62L with the Dynamic Servo Tracer Tonearm. Not quite sure on its claim but according to my research, Denon's Servo-Tracer tonearm is a decided help in coping with warped records. This unique arm is guided by an electronic device which compensates for the seesaw motion caused by the record warp and keeps the stylus pressure constant despite these up-and-down undulations.

Wow, I noticed the difference in sound reproduction immediately! The distorted harmonics played through my Dual 701 was nowhere to be heard through the Denon. It's totally clear as if the record being played was totally flat (even though you still see the seesaw action happening!). Not a hint of distortion whatsoever! I am very impressed by this feature, yet quite unclear yet as to how this arm compensates. Has that something to do with the "Q Damping" adjustment knob? Anyone have some insight??