@o_holter I have been using a long-in-the-tooth Clavis DC on and off for years. I have not experienced any woofer pumping in my system. If I may make a suggestion (I'm assuming you are using sorbothane pucks in your HW-19) you might consider using a different Duro rating, maybe softer. Another potential culprit might be the bearing. An "oil change" and cleaning may help. Check the best to see if there is any obvious wear that could be getting into the platter assy.
I used the Clavis DC briefly in my VPI HW-19/III (spring sprung, not pucks) until changing to a modified TNT and then to an Aries Extended. Arms used include Premier FT3 with Sumiko Analog Survival Kit arm wrap, Jelco 750D and JMW Memorial 12. Never an issue.
I used the Clavis DC briefly in my VPI HW-19/III (spring sprung, not pucks) until changing to a modified TNT and then to an Aries Extended. Arms used include Premier FT3 with Sumiko Analog Survival Kit arm wrap, Jelco 750D and JMW Memorial 12. Never an issue.