"""" Now and this is something that almost no one take care when talking of the FR 66/64 and is that that touted ( @lewm ) high mass is the other serious problem of those arms other than the main non-damped design.
In those old years tonearm designers and TTs ones were in favor of high mass to damps its products. On tonearms was SAEC whom publicited " papers " explaining the tonearm advantages of high mass designs as their models but were totally wrong because they don’t took in count how it really works the cartridge/tonearm combination along the spining LPs.
Exist no single LP that comes with precise/perfect concentric hole for the TT spindle to avoid the normal " excursions " during playback. Those " excursions " ( lateral movements. ) along the other characteristics for the cartridge very hard work ridding the LP grooves means that as higher the effective tonearm mass as higher problems to " stop " the inside/forward to the spindle natural path of the tonearm because of those movements.
Lower mass tonearm has lot lower problems to stop that natural inside inertia to follow in better way the LP grooves.
That dynamic mass/high inertia goes against a precise and clear sound and per se produces distortions ...........""""
Here you can read what explain in better way the very high problems of high mass tonearms like the FR/SAEC ones. What you read is an explanation how it works dynamic mass/inertia with cartridges I took the information from SS site and the explanation comes from PL owner/designer. ) that is similar what happens ( one way or the other ) with high mass tonearms designs. No it’s not exactly but you can have the whole idea of what I posted not only here but years ago in this same forum:
"""
On the left is a relatively SMALL Moving coil armature, the right is our LARGEST tiny permeable flux modulator. You can see by the obvious size differences that the moving-coil system has far greater mass, which means much higher inertia. That is a bad thing.
A large amount of mass in the moving system is greatly detrimental to the performance of phono cartridges. One obvious reason is the simple aspect of just getting the mass moving; moving this mass and then reversing its direction quickly as described above. The more mass, the more stored energy, and the longer it takes to get it moving (and the more difficult it is to reverse its direction).
One of the most important problems that arises from too much mass (or inertial problems) is what is the path of this "stored" energy? Where does it go??
The simple matter is that once you store energy in the moving system the stored energy must go somewhere to be dissipated or gotten rid of. Some of this energy gets damped, but a very large amount of this energy reflects back down the cantilever and into the stylus – which tries to put this energy into the record. This is extremely bad.
Since cartridges are designed to receive energy from a record, and not put energy into a record, large problems occur when this issue emerges. When there is an attempt to try to put energy back into the record the result is that the stylus jumps horribly within the record groove, and does not stay in intimate contact with the groove walls. Its like a badly designed sports car on a bumpy road. The resulting signal that is created is not entirely representative of what is recorded in the groove. Becasue it behaves like a tire on a bumpy road it spends lots of time in the air, and not much time in contact with the road surface. The stylus’ attempt to put energy into the record results in what is technically called a “mechanical impedance mismatch” – lots of energy being driven into a small mass (the stylus), which cannot “move” the massive record groove. The result is “groove jitter” and poor statistical-contact with the groove walls. If you cant stay in contact, you cant hear what is truly on the record! After all, if you don’t read all the words, you wont get the story ! Our job is to get you the entire story, not bits and pieces of it ............so how do we make this happen?
If you lower the generator mass, two important things happen: Less effort is required to move it, and less energy is stored by inertia, which results is far less energy reflecting back down the cantilever and into the stylus. This means less jittering of the stylus in the groove, because it has less energy that it is trying to put into the record. """"
That's what happens too in all high mass TT platters designs: storaged energy. For year too, I spoke and posted that that very high dynamic mass on TT platters induce distortions/resonances/micro-vibrations because every " body " in movement has it. We can't go against Physic Laws.
If it's true that on BD designs some kind of mass is need it ( higher than in DD designs. ) the high mass design path makes more harm than improve any single high mass platter design.
All today followers of that kind of wrong strategy that started the Japanese TT manufacturers are not only wrong but in worst condition that those very old Japanese TT designs because today BD TT platters comes with even 10 times more higher dynamic mass than the old designs. ! ! ! !
Yes, we have to stay aways of high mass tonearms and high mass TT platters design. Goes against MUSIC.
Regards and enjoy the MUSIC not distortions,
R.