Direct drive vs belt vs rim vs idler arm

Perhaps I missed it in the six previous pages of this thread, but there is an issue with belt drive suspended tables that is often overlooked. If the motor is mounted somewhere other than the subchassis along with the platter, then belt tension varies with suspension movements. There's no getting around this. Even if the belt has less stretch than rubber, the belt becomes part of the suspension. It's part of the suspension anyway in this case.

Suspensions are designed to compensate for acoustic impact on the table and they're tuned to a low frequency. When one sets up a suspended table it's made to bounce straight up/down. This straight bounce only occurs if you push on the suspension precisely, and in the right place usually equidistant from the springs. Hit the suspension in the "wrong" place and the perfect bounce becomes imperfect. Sound waves don't obey the rules dictated by a suspension and will hit the table in unfortunate ways.

I read a diatribe here about the Goldmund Studio and how the Delphi was so much better. It's true that the Goldmund DD's had an unfortunate suspension, but at least there was no belt involved. This was something that everyone came to realize and it became di rigueur to defeat the suspension.
Okay, we're not talking about the stock table any longer, but a Goldmund thus modified was far superior to a forgiving Delphi with its mushy sticky mat and speed variations. Even without the suspension defeated it was a more precise deck capable of extracting more information. The methacrylate platter was a prototype for platters/mats that are designed for physical properties compatible with vinyl.

It's no coincidence that Japanese statement decks of the late '70s early '80s were virtually all direct drive. When the CD was introduced in '80 they were phased out. The "superiority" of belt drive was sold to the public because that was the only option for a small manufacturer. They didn't have the technology or the motors to duplicate the Japanese decks, so they did what they could.

Belt drive has come a long way and some are much better than those offered in the '80s. Now, well into the resurgence we come full circle. Before '90 VPI had the HW19 and the TNT was just introduced. Now their top deck is Classic Direct, go figure.

Fleib, Your points are well taken; I am no fan of suspended tables, but suspension vs no suspension is yet another choice, in addition to, not instead of, belt-drive vs DD. As you note, a suspended DD turntable would not be subject to the belt stretch you mention. But in fairness to TT's of the suspended/belt-drive class, none of the current examples that I know of still mount the motor on the base, rather than on the suspended element. The old SOTA tables were guilty of that flaw; my Star Sapphire Series III was just awful on sustained piano notes, as a result. For years, I thought the muddy piano sound was part and parcel of vinyl reproduction. Modern SOTA tables are no longer built that way, and old ones can be modified, according to my reading.

Lewm, I don't know what you think of my SME 30/12, but it is a modern belt-drive, and the motor is mounted on the sub chassis which is separated from the platter by the four suspension towers. This prevents motor vibrations from effecting the platter and arm.

The owners of these SME tables with whom I have spoken do not hear issues with sustained piano notes. Perhaps others have had different experiences.

I have not heard the GP Monaco turntable, but one owner I know regrets having sold his SME.

Fleib, I believe the SME suspension is designed to be effective in all directions, not just the straight/perfect up and down movement.

Lewm, Peterayer,
I believe the 30/12 was introduced sometime near the beginning of this century and is example of what I meant by "having come a long way".
Sota on the other hand, like Oracle, seem to have their heads buried in the sand. My apologies if these have been redesigned, but you simply can't have a suspension, especially a bouncy one, and a fixed motor not moving with that suspension, without serious consequences. They might work pretty good until the suspension is excited, then speed variations and/or sideways forces on the suspended parts wreck havoc.

When I was a high end "turntable guy" I was always amazed by some people's inability to hear speed variations. This can be learned just like perfect pitch is now taught in music schools. It can be a two edged sword though, you might not like what you hear from your rig.

The Sota Sapphires were a mess. The motor was fixed to the plinth and a heavy subchassis/platter hung from the same plinth made out of 1/2" MDF. The three feet that support the whole affair were also attached to that plinth. The belt was replaced (90's ?) by an even flimsier one that insures poor speed stability. The subchassis was made of 1/2" MDF with a lead sheet laid on, and weight blocks on the corners except the arm area that had a reservoir for lead shot.

I still have an old Sapphire I took in trade. It sits in a corner looking pretty. I never could listen to it for more than a short while. I started to redesign it, but the subchassis is warped and azimuth is crazy. I like the platter and I'm thinking of a more extensive redesign with a metal chassis and Verus motor w/o suspension.
It's my understanding that Sota is basically the same today, except the Cosmos which has the motor mounted on the subchassis. I'm no longer familiar with Sota top models, but I imagine it could be looked up. Sota was always very secretive about their designs. They seem to be the only company to disallow their info in the VE database. Wonder why?

Regards,

Lewm -
There are no sides here. I am reminded of the old doctor who unfortunately misunderstood a lady who wandered into the clinic and complained of acute angina.

I have been fortunate to acquire an exceptionable turntable that still outperforms anything I've heard, which includes the SP10's, L07D's and the big Micro Seikis. Ironically HP described the sound of the Final Audio VTT1 as "sounding like a direct drive TT" when he auditioned it in the 70's.

Artisan Fidelity does a fantastic job restoring and improving turntables. In my view the old direct drives need to be blueprinted and recalibrated in every respect, both electrically and mechanically, due to age.

The weak point of the SP10mk3 is a substandard plinth system that does not provide loop rigidity between platter/bearing/arm/cartridge. Artisan Fidelity build a new plinth with both far superior loop rigidity and and If you examine the Artisan Fidelity SP10mk3 upgrades - rigid plinth, energy drain to ground, copper record interface mat - the Final Audio had these attributes as standard back in 1971.

In 1971 the Final Audio had a rigid skeletal plinth, the base of which is 40kg slab of Superplastic Zinc Alloy, at room temperature this material grain slides at a molecular level when excited between 10-100hz. The gunmetal arm pod is bolt to this energy sink as is the inverted bearing. A platform made by Otai composed of a constrain layered structure of hardwood plywood and crushed stone ( used as a base under the bullet trains ) was the recommended interface to sink any residual noise to ground (earth).

The platter system uses 4.5kg copper mat and 18kg aluminium platter ( solid profile, not a ring bell shape ) and a gunmetal clamping system to drain unwanted energy from the stylus/record interface to ground. Final claimed at the time that even the shape of the underside of the platter had been designed to squeeze noise out.

The Artisan Fidelity Statement 301 - has a 19lb platter composed of aluminium/copper with an inverted bearing - again the Final Audio had this back in 1971.

As far as drive train goes - the Final implemented, back in 1971, a regenerated power supply that included sine and cosine wave generator, with infinite control of speed ( not stepped ) and control over the level of torque applied. The AC motor locks precisely, if an AC motor lags at all, it corrects sinusoidally, in a very benign manner.

This drive train is more sophisticated than any of the big Micros and Melcos that came about in the late 80's, some years after the Final was built. The energy drain design of the Final again is far more sophisticated the the big Micros and Melcos as is the speed stability ( the Micros use DC motors )

So I am not anti drive of any kind - it is more about implementation. There are only a handful of exceptional turntables out there in my experience.