magnetic drive turntables

Do Grados hum on these TT's?

Hiho, The turntable you describe is actually less like direct drive than belt drive. The advantage of direct drive is that there is no compliant medium between the motor and the platter. In this case you have a traditional belt driving the sub-platter and then the addition of another compliant medium between the sub-platter and platter. The magnetic coupling, while interesting, behaves just like a belt. It "stretches" to filter out cogging and noise (good) like a belt. But it also delays delivery of torque (bad) just like belt.

So what you have is essentially a belt drive table with the equivalent of an extra belt inserted between the motor and platter. While this may sound fine to some it is really the opposite of direct drive

Best you couple your 'magnetic drive TT' with an electron microscope base, only course if you have the $50,000. Don't fall for the hype, and stealing, that these hi end TT promise.

I'd think a DD table on a magnetic suspension would be better. Would all that magnetism effect the cartridge?

Teres, you are right about it being more like a double compliant system, closer to belt-drive than direct-drive. I guess I was intrigued by the idea of the platter being center driven. Using the same set up and if I replace the motor pod with a stator, coils, then it will act like a direct-drive table except the stator is decoupled from the main chassis to avoid back torque energy (good). For yucks, just an idea...

Thanks for chiming in.

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I believe Transrotor uses a similar system.

http://www.transrotor.de/code/de/produkte/plattenspieler/tmd.html

Technics SL 1200 has a magnetic direct drive mechanism that sandwiched between the platter. It is not priced at 50k.