Weight of my cartridges: 2m bronze: 19.615 g Grado m+ mono: 15.21 g AT 120eb: 12.71 g My pioneer pl600 works fine with the 2m. Hard to adjust the counterweight when there is that big of a difference in headshell weights. Dimes are 2.2 g each. Add a couple dimes on top of the headshell to test the weight? (2 for the mono and 3 for the 120eb?). That would make them each weigh approximately the same. Is there a reason that adding headshell weights wouldn't work?