Direct Drive turntables

Dertonearm, Have you seen the photos of the new "direct idler-drive" turntables to be marketed by TT Weights? There are two models, one megabuck and one for under $10K. But both sport VERY heavy platters in the 30-lb range and higher. I thought that would make you happy. (Unless your minimum criterion for Nirvana was >30kg, not >30lb.) Still, those are fascinating products.

Dear Alec:+++++ " Hi, has DD a "theoretical" advantage over belt drive that will translate into better sounds? " +++++

IMHO the opinion on DD advocates can tell you " several " advantages " and in the other side the BD advocates can tell you too the " advantages " on this design and maybe and only from the theoretical point of view both ( some way or the other ) can/could be right about each single advantage.

Now, a TT audio item is not a set of " single/aisle " advantages/disadvantages but a whole finished audio item with intrinsic trade-offs ( there is no perfect TT. ).

Where reside ( mainly ) those trade-offs? ( certainly not on the TT drive design. ) and this is a hard question with many answers, example: type of bearing, TT plinth, kind of motor choice, platter build material, arm board build material, TT " system " vibration/isolation ( external/internal ) mechanism, whole TT quality/build execution,.

These and many other factors are the ones that makes the " differences " and IMHO you can get/have the quality performance you are looking for with either TT drive mechanism.

Some people here and there try to put " things " in a very simple manner/way but the TT ( stand alone ) quality performance can't be judged in aisle way because this audio link is only a part ( important one ) of the whole analog chain where our ears and music/sound priorities are part ( too ) of that analog chain.

I'm almost sure that if you/we take a top BD ( like the one you own or a Walker. ) and a top DD ( say Mónaco ) with a matched tonearm/cartridge and care to set up ( the same for both TTs. ), same arm board build material, same suspension/isolation mechanism, same mat and an un-biased attitude you /we can't hear any detectable difference other that what we " want " to hear.
Now if both TT are designed the same ( mainly on build materials ) my " almost " sure can convert on a simple " sure " no detectable differences only because the TT drive system.

The Jfrech comparison help to tell us that the differences ( IMHO ) comes mainly for the TT design differences more than for the TT drive mechanism and in the case of his friend due that the tonearm in the TT's were different!!!!

The analog imperfections like an audio chain makes extremely complex to have a " simple " answer to your question: the whole subject is very complex and till today I don't read/know ( anywhere ) a precise answers that can be corroborated in a scientist/theoretical/mathematics model. Till this happen the best way to go is to have first hand experiences and decide ( take action ) in consecuence.

Btw, a good alternative is to own/run BD and DD in the same audio system and forgeret about useless " controversies " on that subject.

Regards and enjoy the music,
Raul.

Lew, TTW do look interesting and are located to the south of where I live ,sometime into the New Year I plan on a visit for a look & listen.

Dertonarm your point about platter mass on this Denon Cotter table, could a re-fit platter with a much heavier design work without damage or modify the existing platter in some other way?
Also when do you plan on releasing your turntable onto the market?

One final question, anyone here Albert Porters Panzerholz plinth design?

Stiltskin, I believe that a high mass (whatever high mass may mean in the individual case...) platter can be fitted only to a direct drive if the heart of the drive - motor and axis - is designed with the respective resulting inertia and pure vertical mass in mind. As the direct control is in most cases an essential design parameter of a direct drive.
I for one wouldn't dare putting a 30 lbs (but I would favor 30 kgs anyway Lewm....) platter on a Denon drive coming originally with a 6 lbs platter. At least not for very long.
A direct drive working with a high mass (and resulting very high inertia) platter has to feature other design parameters in some key components than the average dd from the 1970/80ies.
Aside from that - not the material of the plinth is the core issue, but the internal damping (not bad with Panzerholz, but even better in composite materials) and most important the resonance frequency of the suspension.
I can not stress that point hard enough. Please remember that it was AR with its very first suspended TT which single-handed put in motion record playback high-end (a decade and more later adapted by Linn with their LP-12).

A happy new years eve and a healthy, peaceful and prosperous 2010 to all analog A'goners!
Cheers,
D.

Dertonearm knows I do not necessarily concur with his gross generalization regarding platter mass, as it may apply to anything other than a belt drive turntable. But we have beaten the subject to death on another thread. However he is quite right; it would be folly to add a high mass platter to any direct-drive system that was designed for a relatively low mass platter, based on my reading of posts by other more knowledgeable persons (specifically "Steerpike" and Mark Kelly, over on DIYAudio, who were discussing the design of a modern controller for an SP10 MK2 or Mk3).

The Kenwood L07D is interesting in this regard. It has a "relatively" high mass platter, much of which mass is concentrated at the periphery of the platter, and the servo system is designed to cut in and out once the platter is up to speed, so in part it depends upon platter inertia to maintain stable speed, like a weak belt drive with a massive platter. In addition, the magnet assembly that forms part of the motor is actually affixed to the underside of the platter, as in the SP10 Mk3. Thus the platter is in effect part of the motor and in theory the only "noise" injected into the playback could be that from the bearing itself, much like any belt-drive. I hope to have my L07D up and running by the end of January.