No idea about the modern Rega decks, but the old Planar 3/RB300 can be improved by a quite startling amount by simply loosening the big nut holding the arm onto the plinth. Just set it to the point that armbase doesn’t move when you use the cueing device, and no more than that. You don’t need a spanner to tighten it, just your fingers is more than enough. That done the thinness, leanness and any tendency to sibilance is reduced and the deck starts behaving like a far more expensive one.
PS I’d love to study this as it applies to so much audio and seems consistent in effect across most decks, arms, speakers, speaker stands etc. My best guess (and without access to proper lab conditions, accelerometers etc that is all it can be) is that loosening this joint helps prevent a resonant reflection from the mass of the plinth that otherwise echoes back up the arm tube to the cart like a tuning fork. Rega’s recent approach, which I’m sure is grounded in the same phenomenon I’m hearing, is to remove as much mass as they possibly can from the plinth. That makes a lot of sense to me and I suspect this tweak won’t work with their modern foam-laminate plinths, which are likely very lightly torqued by design. In fact it wouldn’t surprise me if their current three-screw arm fitting was designed to allow far lower torque settings, i.e. the armbase can’t rotate when using the cueing arm at all now.
