Mulveling, Are you saying that your platter in effect bounces up and down on its magnetic suspension when sufficiently disturbed?

@lewm It does so visibly, in the extreme case when I walk by heavily (I’m > 200 lbs) on a bouncy floor with unbraced rack. And in the slightly less extreme case, when playing back at loud SPLs (mid-90 dBs average), large woofers can visibly "flap" - this flapping is NOT present on a rigid bearing non-suspended design like VPI - same room, rack, everything. Of course, those tables have their reactivity in the audible bass range - the feedback even sounds similar to ground hum at times.

Every model of CA Innovation is susceptible to this - I’ve had them all - Compact, Wood, Master. It you push down on the platter it feels "springy", albeit less linear than with actual springs.

The SOTA can cause big trouble too, if the suspension is excited by significant event. But THAT is relatively easy to solve with rigidity in the right places - and the suspension provides a ton of value in its massive isolation of frequencies above resonance.

Yes, I’m aware stacking suspensions is bad news - I’m sure SOTA’s very gifted engineer/designer is aware of that and made sure to avoid deleterious overlap of resonance. I’m just curious about the design of SOTA’s bearing solution compared to the Clearaudios I’m familiar with.

Audiophiles who keep their volume levels below 85dB, and those on concrete slab, will probably never experience the issues I'm talking about. 

There was a bass extender module for them, which this pair has. Makes them look like Wilsons or those LS3/5A with their bass modules. Has a 7" Focal woofer in each cabinet as I recall. 

@neonknight Yes- no that you mention it, we had that at CES. The bass cabinet helped a lot.

FWIW, In any proper turntable you don't want any play in the platter bearing or tonearm bearings- and the coupling between the mount of the platter bearing and the base of the amp must be as rigid and 'dead' as possible. In this manner it makes it more difficult for the cartridge to pick up vibration at the platter since it will be common to the tonearm as well.

Sorry I do not see a magnetic bearing storing energy and act as a suspension. Have you ever tried holding two strong magnets and then compressing them together? Takes a lot of force to do this. Now this bearing rides on a fairly complaint suspension tuned to 3 Hz. Any force that tries to compress the bearing is just going to move the suspension. The platter weighs 9 pounds, so its going to take a lot of energy to make it change position relative to its stationary position created by the two magnets. I don't know about you, but I don't beat my turntable hard enough to do that while playing. And the suspension isolates it from outside forces. 

@atmasphere There was a bass extender module for them, which this pair has. Makes them look like Wilsons or those LS3/5A with their bass modules. Has a 7" Focal woofer in each cabinet as I recall. 

Mulveling, Are you saying that your platter in effect bounces up and down on its magnetic suspension when sufficiently disturbed? So far as I know, the first fully maglev bearing is on the Verdier.  SOTA have it now I think. My Kenwood LO7D platter is partially suspended  in the vertical plane by magnets.  There are others besides the Clearaudio.  Anyway, the Verdier bearing is solid as a rock.  So is my Kenwood bearing, albeit it should be as the platter does make contact with a solid thrust pad while the magnets just reduce the burden. I don't actually know of any maglev bearing that has much give in it so as to allow the platter to move up and down with room disturbances.  Nor can I really say that is a horrible thing. I just ran it up the flagpole to see who would salute it.  But you can imagine that the SOTA mag bearing ought to be solid, because the Cosmos also has a spring suspension. You would definitely not want the platter to be excited while also the spring suspension is excited.

A well conceived magnetic bearing should have no "bounce" in response to external energy like footfalls, etc. If it did, you could have the above problems, especially on a TT with a spring suspension.

@lewm Do you happen to know how this is achieved (a well-conceived one, that is)? I’d be real curious to learn. The benefit of a vertical-thrust magnetic suspension is the reduction in friction. The downside being you now have a suspension that can trap energy when excited. And most mechanisms to damp that energy would create far more friction than was saved in the first place.

Clearaudio’s implementation has the downside that they pile LOTS of platter mass on top, and then the magnetic thrust is only "just enough" to oppose this, plus a few pounds for clamping. So when the platter gets disturbed, there’s quite a bit of displacement and visible low-frequency oscillation (and in your woofers if you’re unlucky enough).

@neonknight That was a long time ago! It was not a large speaker though and IIRC was a 2-way.

@atmasphere Any chance you can provide any details about their build or sound? 

One interesting tidbit in this letter is the mention of the Panorama speakers SOTA released. There is an ad out there for a pair of the speakers on the other side of my state, and they have been listed for quite a while. If I were a collector the speaker would be worth seeking out...but I do not have room for them. Still they are tempting!

@neonknight When SOTA was marketing that speaker was during the early-mid 90s, during the short period when Allen Perkins was with them. We showed with them at CES; I think that was about 1991. Allen had moved from Minnesota to California to work with Sumiko (SOTA); he had been previously employed at House of High Fidelity here in St. Paul, who was a SOTA dealer. IIRC Allen had a lot to do with the design of that speaker. 

A well conceived magnetic bearing should have no "bounce" in response to external energy like footfalls, etc.  If it did, you could have the above problems, especially on a TT with a spring suspension.

@mulveling I have a Cosmos Eclipse and the magnetic bearing works well. No issues with suspension interaction or anything else. Now is it a sonic improvement over the sapphire bearing? That I do not know. But given what I see turntables selling for, a completely updated Sapphire for $3K seems like a lot of table.

The magnetic platter is cool and eliminates most of the shipping problems, but I have to admit the practical performance of the sapphire bearing is pretty darn remarkable. It sure was a sensible solution for its time period, and still viable today. If I was buying a turntable I would think long and hard about either buying a used SOTA and having it restored or getting a refurbished one from them. Apparently Christan at SOTA is producing some videos to document the process of doing spring restorations in the field.

@neonknight I’ve been wondering about that as well. The old sapphire thrust plate and zirconium balls perform SO well, I’m not sure I understand the move to magnetic. It’s also not hard to ship the former correctly.

I’ve had many year now on various Clearaudio Innovations, with their own version of magnetic thrust bearing, and they are VERY reactive to any stray subsonic energy (right in the woofer-flapping range). It can be a huge problem in some systems (and if you think that's bad, the magnetic bearing arms made it even worse). Not sure if SOTA has mitigated this somehow; the further interaction with springs could make it better or worse. I suppose it’s also possible to use magnetic thrust just to *reduce* the load on a traditional bearing, rather than providing 100% thrust / suspension.

Agreed that modern SOTA prices & services are quite dear. When I see a clean SOTA on the secondary markets, it always seems like a smokin’ deal to me. Recently picked up a mint Cosmos that the owner had recently serviced by SOTA (still in their sealed packing) and am grateful to have it. Wonderful table. It’s a series V that has the traditional bearing, but was upgraded to new Condor motor & PSU. I’m not even sure I’d want a SOTA with magnetic bearing, and now I hear their new / upcoming top table is not even suspended? I have to scratch my head at some of the new directions.

We just got back from Puerta Vallarta for an enjoyable trip for el Día de Muertos and this is my first weekend getting to sit back and listen to some music in the morning. The weekend is when I spin most of my vinyl, and for the past few weeks I have been using this early SOTA a fair amount. I am pretty impressed on how good it is even after all these years. Further up in this thread @petaluman posted a review of that early SOTA table and its speed tests were pretty darn good. 

Now I have never been a big vintage-head audio guy, even though I have used what is now considered vintage electronics in the past, like a Rowland Model 5 amplifier, a N.E.W. amplifier, a Superphon pre-amplifier, and a couple of other things. Heck I owned my last DAC for 15 years, from new to vintage. But I would have to say that there is real value in vintage tables. I have had a Thorens TD124, Garrard 401, Technics SP 10 II, and Denon DP75. I would say in the world of analog there is a lot of value in vintage. 

I always knew SOTA refurbished their tables, but their services were not cheap. However, someone in our local music group bought a refurbished Sapphire from SOTA and it is a very nice table. Given what turntables cost new today, the price does not seem terribly unreasonable. Now the used tables out on the second hand market seem to be a bit undervalued in my opinion, although the prices are rising. I do see on their website they have restored Sapphires for about $3K with Series 6 motor and electronics and the magnetic platter.  The magnetic platter is cool and eliminates most of the shipping problems, but I have to admit the practical performance of the sapphire bearing is pretty darn remarkable. It sure was a sensible solution for its time period, and still viable today. If I was buying a turntable I would think long and hard about either buying a used SOTA and having it restored or getting a refurbished one from them. Apparently Christan at SOTA is producing some videos to document the process of doing spring restorations in the field. 

Anyways, this has been a fun table and I am sure a lot of people would enjoy it. I wish it had the full wood top and the acrylic platter. But for a casual table its really all I need. It sounds pretty darn good, even though there are "upgrades" that came down the road. 

I have a Sapphire, Gen 1, that I purchased new, and (like the rest of my high-end system) haven't used since moving to New Jersey and getting married. I don't know what tone arm this is, and it has a Grado cartridge mounted on it. There is also a spindle clamp. And in a cabinet drawer, I have an equally old Koetsu Rosewood with the stylus missing. The SOTA shipping box (I remember, it was a robust piece of work) was destroyed in a nor'easter years ago.

After all these years, I don't dare turn any of this equipment on. Probably catch fire. I'm just saying, I appreciate this thread.

Had a Sapphire mk II bought new 1986 with a Sumiko MMT tone arm.  Had the 4 point suspension and standard wood arm board.  Sold it to my roommate in 1990 to partly fund purchase of a Star Sapphire mk III in 1990.  This latter table has an SME V arm with a multilayer Cosmos arm board.  Both tables were representative of the original company and were built in Oakland, California.

Both still in use today and function very well with minimal maintenance.

@dover I got some paperwork with the SOTA and one of the documents was a SOTA newsletter that laid out the upgrade path. It was postmarked Nov 27,1989. One section discussed the SOTA upgrade path to current generation tables. The Gen 1 model was from July 1, 1981 to 1986 and up to serial number 15167 for the Sapphire. My table is 15013. While this table looks like it has been lovingly cared for, I would guess it has never been back for upgrades since it still has the aluminum platter. 

I doubt many of the mats have survived for this table, and if they did I imagine they are compromised. I will search for an appropriate replacement, and for now the cork and rubber one will work fine. 

One interesting tidbit in this letter is the mention of the Panorama speakers SOTA released. There is an ad out there for a pair of the speakers on the other side of my state, and they have been listed for quite a while. If I were a collector the speaker would be worth seeking out...but I do not have room for them. Still they are tempting!

Do you remember what they used on the Gen 1 table then? A rubber mat? This one came with a felt one but I fitted it with a rubber and cork one I had available. 

 

Depends what you call Gen 1.

 IIRC the original mat was acrylic.

Definitely not rubber, for sure.

That's not correct - some time pre 1984 the original Sota came with a lossy blue mat - with the sponginess and feel of wet rubber.

The acrylic mat came somewhere around 1984, I remember the first supermat system ( for non vacuum Sotas ) which consisted of a revised acrylic mat (slightly translucid) with a rubber underlay introduced in 1985.

I was a distributor for Sota at the time.

The acrylic mat has since been through many revisions from the mid 80's.

Definitely not rubber, for sure.

@neonknight IIRC the original mat was acrylic.

Oracle makes an excellent patter pad that would be well suited on there.

@atmasphere  Do you remember what they used on the Gen 1 table then? A rubber mat? This one came with a felt one but I fitted it with a rubber and cork one I had available. 

@neonknight  @lewm  That would make two of us. More than anything vacuum clamping results in amazing pitch stability and lower low frequency background noise as long as the record is reasonably concentric. There is no other downside. I will never buy a turntable without vacuum clamping. Sota's current system is extremely quiet. In my set up it is totally inaudible. The only kinks in operation are you have to turn the table off to remove the record and the vacuum generates an amazing amount of static charge on the bottom of the record. I deal with this problem by using my own formula of record cleaning solution that will not allow the record to collect a charge. This fluid is currently being evaluated by Sota. The only solution to stopping the table for every side is to get use to it. 

My memory is not the greatest, but I do think the initial vacuum tables were regular Sapphires before the Star was released. I never used any of the early vacuum tables. My first vacuum table is my current Cosmos which is only about three years old. The only time the Cosmos has trouble clamping a record is if the record is dished. It will clamp the concave side, but not the convex side even with help. With the use of Sota's reflex clamp I have yet to have a record not seal with the exception of dished records. 

If all aluminum I think there was a Supermat that was used to damp it.

@neonknight The Gen 1 Sapphire did not use the 'Supermat' as I told you earlier. Here is more information:

The Supermat was designed by Warren Gehl of Audio Research (although years prior to his employment there). Sumiko owned SOTA at the time they acquired rights to his platter pad, which was dubbed the 'Supermat'.

Its first appearance on a SOTA product was on the Cosmos. After serial number 100 they changed the formula.

The Gen 1 Sapphire predates this period so did not use the Supermat.

In terms of who did vacuum clamping first, what about Micro Seiki, and what about the Audio Technica vacuum mat? Where do they fit in historically? There’s also the Victor TT801. Most likely that latter TT predates SOTA, but I don’t know for sure.

Incidentally, I think the vacuum strength on my Series III was already internally regulated. I don’t recall being able to adjust it.

@lewm Ah yes! That was an observation that others had about the early tables. I do remember one reviewer mentioning this also, and he found the best setting for him was 1/3 of the dial on vacuum pressure. 

The new tables do not allow you to adjust pressure, there is a factory algorithm followed. There is an initial pressure applied to clamp the record and seal it, and then it is reduced to a maintenance level. On my Cosmos you have to remove the air hose to get the table to play without vacuum and I did that early on. I never noticed a degradation due to the clamping of the record, if anything I achieved improved resolution and fine detail in playback. I am satisfied with how the system works. 

Except in the case of my Star Sapphire III, the vacuum clamp introduced a faint dull haze over the music. Sounded better with vacuum off.

@mijostyn Some sites show 1980 some 1981

General

• Manufacturer: Luxman
• Model: PD-300
• Type: Turntable without tonearm, with built-in manual vacuum platter suction
• Years of manufacture: 1981 - 1985
• Made in: Japan
• Color: Silver, Wood
• Remote control: -
• Power consumption: 15 W
• Dimensions (WxHxD): 490 x 200 x 390 mm
• Weight: 18 kg
• New price approx: 163,000 yen (Japan, 1981), about 2,500 DM without tonearm and without system, with Elac ESG-796 H 30 (according to Stereoplay 11/81 + 1/83 top class group 1) 3,150 DM market price.

Vinyl Engine says

Luxman PD 300

Belt Drive Turntable (1982-1984)

An AI search engine gives this answer

You’re right; there seems to be some confusion around the release date of the Luxman PD-300. While many sources cite 1975, others indicate it was introduced in 1980. It’s not uncommon for vintage audio equipment to have discrepancies in dating. If you have a specific source in mind, I’d be happy to help clarify further!

So far even the latest search date slightly predates the SOTA Star Sapphire which is 1984.

Steven W. Watkinson, Various | Sep 5, 2008 | First Published: Feb 5, 1984 The SOTA Sapphire was the first, and the most successful in terms of sales, of the new generation of high-end American turntables.

AI Search engine shows

You

release date of sota star sapphire

Copilot

The SOTA Star Sapphire turntable was introduced in 19841. It was an advancement over the original Sapphire model, featuring vacuum clamping to further reduce vibrations and improve sound quality.

@neonknight The PD300 was produce from 1982 to 1984. I do believe that SOTA beat it out but it was close.

It is entirely possible for a suspended turntable to take multiple arms, the Dohmann Helix 1 is an example. Sota could easily make one on the basic Cosmos design. They are turning the Millennium into a multiple arm turntable, but by removing the suspension, mounting feet on the chassis and a heavy base under the feet. No dust cover. Not my cup of tea. You could take the chassis and place it on a MinusK platform. Then you would have to concocted a dust cover.  

I am sure the platter speed was well beyond 78 rpm by the time he yanked the plug out of the socket.

@lewm I bet that was amazing to see! Guess the pitch controls were not going to have enough range to dial that down!

I think the Gem post dated the early years and was an attempt to appeal to budget conscious buyers. My anecdote about the platter taking off was intended as humor, but the platter speed was truly out of control and gaining in velocity. My friend discovered he had failed to connect a feedback loop that was key to speed control. The platter did lift up off the bearing just before he cut the power. Believe it or don’t.

@mijostyn It appears that Luxman introduced vacuum clamping on the PD300 in the late 1970’s. Sota released the Star Sapphire in 1984. Apparently, there is also a SOTA GEM which was a precursor to the Sapphire and the first table released by SOTA.

The arm for a SOTA needs to be under 2.2 pounds and fit the landscape of the arm board which precludes these VTA tower type arms such as Wheaton or Reed. Unless you cut and modify the top of the plinth. These suspended tables will never be multi arm ones, I don't know of a suspended table that is easily fitted that way. 

On My SOTA Cosmos Eclipse I put an Origin Live Agile, and Christan built a custom arm board for it that looks like a breastplate underneath in order to make the weight requirements and still be non-resonant.

@lewm I have never heard of a Sapphire being offered as a kit. Nor could I think that motor could spin a 1 inch aluminum platter fast enough to give the impression its coming off the turntable. That sounds like a runaway direct drive motor. But perhaps it was the GEM, as there is so little information out there about it.

As far as this Gen 1 SOTA Sapphire, it certainly is playing well. It makes a great casual table for me. I had a Gen III Star Sapphire a few years back that I got as a proof of concept before I bought my Cosmos, and I used an Audiomods Series Six arm on it with great success also. To be honest, I liked the Audiomods over a SME V that I eventually put on that table and my Cosmos. I am quite tickled with the improvement in sound quality I get with the OL Agile arm over the SME V I had initially mounted.

Now its time to shop for an appropriate platter mat. I have a rubber and cork composite one that does a respectable job. I wish i could find one that is a bit more tacky, something like a modern equivalent of the Platter Matter or even the original Audioquest Sorbothane mats. That would quiet down that aluminum platter nicely.

The version that Mijostyn describes is probably the one my friend purchased as a kit and assembled himself.

OK, David Fletcher was behind both Sumiko and SOTA. The first table Marketed by SOTA was the Sapphire. I had an original one with a Syrinx PU3 Tonearm for almost 40 years and it is still in use in a young audiophiles system. All I ever did was replace belts and lube the bearing. I never had any problem with stretched springs and can only assume these turntables were misused perhaps by using tonearms that were too heavy. The PU3 was a perfect arm for that table. The motor was an AC synchronous with a synthesized drive. You could adjust pitch. The bearing was inverted with a hardened steel ball on a sapphire thrust plate. The platter was aluminum and rang like a bell. I used a felt covered glass mat which was very effective in controlling the ringing. 

This was a landmark turntable. It was the first stable suspended turntable effectively isolating the cartridge from everything over 3 Hz. SOTA would become the first to provide vacuum clamping in a consumer turntable. Through the years the table has maintained it's essential character, but with steady evolution in bearings, platters, mats and drives culminating in the current Cosmos which has a 1" thick sub chassis like an SME. 

Over the years the company has passed through two different owners, the current being Christan Griego. Christan is starting to move the company away from it's core product in a direction some of us might not like. The New Millennium will not be suspended and will allow the use of three arms of any weight. Sota is also working on a direct drive turntable which is also not suspended.  David Fletchers main contribution to turntable design was the hanging suspension tuned to 2-3 Hz. This was a far more stable design that was eventually copied by Avid, SME and Basis. The problem is heavy and /or multiple arms upset the suspension. It would have to be retuned and possibly re springed to accommodate arms of various masses and numbers. Therein lies the real challenge, developing a suspended turntable that will allow the use of heavy and multiple arms without having to resort to major restructuring, something the owner could manage at home. 

Make sure you get a new belt and clean the rim of the platter with brake cleaning fluid until you cloth or paper towel does not turn black. A worn belt will cause a marked increase in wow and flutter. Be very careful with the arms you try. Stick with 9" arms of intermediate to lower mass. The SME IV and V are good examples. Origin Live and Rega arms work well and IMHO the Schroder CB is the best arm for that table unless you can find a Syrinx PU 3 in good condition. I thought so much of my Sapphire that I now own a Cosmos Vacuum table handily the best value in a high end turntable even with the new price increases. 

In theory, shouldn’t a 3-point suspension be more stable than a 4-point suspension, all other things being equal? I guess all other things are never equal.

I don't know much of the history, but older Sapphires started out with a 3-point suspension. Late models (V and up?) use a 4-point suspension. 15 years ago, I briefly borrowed an older 3-point Sapphire (w/ the gold colored platter), along with the Koetsu-branded Jelco arm, and my very first Koetsu (Onyx non-platinum short body = samarium-cobalt).

The 3-point suspension seemed more "springy" and less stable than 4-points - thus it also seemed more sensitive to footstep disturbances / etc. Star (later called Nova) and Cosmos models always used 4 points. Cosmos is most stable of all (more than my Nova), probably due to the aluminum subchassis' extra mass. But any 4-point SOTA is really, really good. The 3 point tables are still very good, but this is an important distinction IMO. I assume the 4-point might also handle a little more arm mass - though my FR64fx's 2.2 lbs is near its limit (I was told 2.5 lbs max).

Are you the same individual who posted this question on AA a few days ago? I responded under the signature Low IQ. I am getting a bit more info from these replies to help fill in some missing links.

I don’t use these AI programs very often but I decided to try ChatGPT and Co-Pilot and see what I could find. They found references I did not in my searches. Co-Pilot says 1" thick 6061 aluminum plate laminated with Baltic Birch ply. Other AI and search engines say its made of aluminum with no reference to Baltic birch. I wonder if they are mixing up the sub chassis in this answer.

For motor Co-Pilot says

The SOTA Sapphire Gen 1 turntable uses a Papst motor.The motor typically requires an unregulated power supply with an output of 28 to 36VDC, 0.15A or greater. Chat GPT was less useful.

The first generation of the SOTA Sapphire turntable typically used a high-torque, low-speed AC motor.

The condition of this table is excellent. The suspension is level, does not have any sag and meets the specs for Sota set up parameters. The finish on the top plate is a perfect matte black, and the frame looks like it might have a polyurethane finish, which makes me think someone has done some level of restoration on this table.

Since the platter is aluminum, I am using a rubber and cork mat on it, with a Sota I-Clamp. I also put on a Cosmos acrylic arm board I have in place of the original MDF one. The arm and arm board allows the table to balance with only a minimal amount of shot needed in the arm board cup. The suspension needs 2.2 pounds at the tonearm spot to balance, so I doubt many arms from back in the day were out of spec for what a SOTA could accommodate.

I have a Cosmos Eclipse with vaccum here, so I know how a Sota should set up. This table is meant for casual use, and for a low mass version of the Audiomods Series Six arm so I can use my Ortofon MC2000 on it. I have one that is OEM minus a new diamond, and one with a boron cantilever that is my casual use cartridge. I paid a modest amount for this table, and I do not expect it to keep up with the Cosmos or my Scheu, but I will say its very respectable in most ways, and an enjoyable table to listen to.

I wonder if many of the faults/limitations about sound referenced in this thread come down to other aspects of analog. Whether it be tonearms, cartridges, phono stages, or perhaps even the arm board materials. As the first one was MDF, and then they made a thin aluminum one before moving onto acrylic/aluminum. Because I think this table sounds pretty respectable as it sits, and I can spend the night listening to it.

Had a Star Sapphire in the late 80's, with the sapphire bearing and aluminum platter. Swapped out Sumiko arm for Eminent Technology straight-line tracker and that made a dramatic difference.  Light weight tonearm probably a good bet. l spoke with the designer, Alan Perkins, back then who then started Immedia where i had their TT and arm. Now he's been involved with the design of the MoFi TT's so that might be a source of sorts.  It's true the SOTA was very vibration resistant and the speed was steady. 

link to 1983 Audio review of original SOTA Sapphire

It mentions the Sumiko Gem also, but not the back story I remember.  My understanding is that the Gem design was a prototype for most of the ideas incorporated later in the Sapphire, including the inverted sapphire bearing.  It was pitched to Sumiko, who added it to their product line.  I don't know if Sumiko, SOTA, or a pre-SOTA company manufactured the Gem.  The above story suggests that Fletcher et al formed a company to build the Gem.  It may have started under a different name, but at some point became SOTA.  SOTA has changed hands a few times over the yeas, but would be worth contacting to see if they can answer your questions.

After seeing how the Gem worked in the marketplace, the more refined Sapphire came into being and was sold direct from SOTA.

I had an early Saphire.....be sure to use a light arm with it.   My Sota couldn't hold an old SME...the springs gave out.

I also owned a Sapphire in about ‘86 w/ a Souther Linear Tracking Arm. It had excellent resistance to foot falls w/ it’s then unique hanging suspension. The platter was all aluminum. The arm board was just cheap MDF secured / basically dry wall screws & overall quality of construction not great. I sold it for the newest VPI at the time which had noticeably better pace & dynamics.

The Souther Arm was a bear to set up & align; when you changed one parameter, they all changed! It was a good concept & could sound very good. Lou Souther sold the rights to Clearaudio whose linear arm  today is based on it. 

I owned two Sapphires in 1985-7.  I had trouble with hyperextended springs with both, and moved on to a Well Tempered TT/TA, which was new then, and kept it for 30+ years.

you could call them up. I think they are in WI, assuming you are in the US.

@lewm That is interesting, I don’t believe I ever heard that bit of info. I know there was a SOTA Gem turntable that predated the Sapphire model.

Removing a platter on the earlier SOTA is not a straightforward task. You have to unbolt the bearing assembly from the bottom and lift the platter and well out as one unit. Then if you want to get to the thrust plate you have to unbolt the clamshell that holds them together. Taking one apart is not much fun.

I have taken a stethoscope to the table and listened to the motor and main bearing. Both are dead quiet, I cannot even hear any residual noise at all. It is really quite impressive. 

I am curious to know if the first generation platter is all aluminum or if it was a composite. If all aluminum I think there was a Supermat that was used to damp it. I find it odd that a google search brings up next to nothing on the early generation tables.

I think in their earliest days, the Sapphire was marketed as a kit. A friend of mine who was technically savvy bought the kit and assembled it. He invited me over for its inaugural spin. This was just a test to see whether it would come up to speed and hold speed. He pressed the start button, and we both watched as the platter spun up faster and faster, far exceeding 33 rpm. In fact, the platter began to lift up off the bearing well, and I feared it was about to take flight, whereupon I ducked under the table. He pulled the plug at that point. Turns out he had neglected to connect something in one arm of the servo system. That early Sapphire was a bare bones TT with a nice wood plinth, not unlike that of the current Sapphire. I think it had the sapphire bearing, but I have no idea about the platter. Anyway, you own one. You are in the best position to assess the build quality and technical aspects.