Garrard plinths are evenly dished from the edge to the center so a record clamp-weight actually pushes the record evenly onto the whole plinth and doesn't lift the edges. if you put something under the center to lift it, it will only cause voids in the middle of the record as just the edges and center is suspended. I also found a ring had no effect on my table in conjunction to the clamp-weight in the center.
This concave platter helps hold the record evenly across the whole surface. so you do not need to raise the center of a record on a Garrard 301-401 table when using a clamp-weight. think of it as pushing a disc into a coned surface the coned surface causes the disc to cone as well and in the process causes a greater contact area in the disc to cone interface. of course this is a very small amounts on your table but the physics are the same.
I would also recommend a good mat and ditch the old rubber Garrard mat. I tried felt, leather, gunmetal-copper (best but expensive as ^%#) and Herbies way better mat (that's what I use now). the Herbies has a cut out for the label if that concerns you.
Glen
This concave platter helps hold the record evenly across the whole surface. so you do not need to raise the center of a record on a Garrard 301-401 table when using a clamp-weight. think of it as pushing a disc into a coned surface the coned surface causes the disc to cone as well and in the process causes a greater contact area in the disc to cone interface. of course this is a very small amounts on your table but the physics are the same.
I would also recommend a good mat and ditch the old rubber Garrard mat. I tried felt, leather, gunmetal-copper (best but expensive as ^%#) and Herbies way better mat (that's what I use now). the Herbies has a cut out for the label if that concerns you.
Glen