SOTA Star Sapphire turntable J. Gordon Holt, August 1987

J. Gordon Holt reviewed the SOTA Star Sapphire in August 1987 (Vol.10 No.5):

Over these many years of audio testing, I have come to recognize in myself a strong conservative streak. One less-than-admirable manifestation of this is that, when I find a product I really like, I tend to resist thinking about the possibility that another might be better.

A reason for this, I suspect, is that if I cannot actually hear anything the matter with the product, I do not wish to learn that my idea of absolute perfection is flawed. Sure, it's easy enough to say "Go to a concert and compare what you hear there with what you hear at home," but while that may be a great idea in theory, it cannot be of much practical value as long as there continues to be such an appalling disparity between real, live orchestral sound and reproduced orchestral sound. We are, thus, still stuck with the same problem that faced audiophiles 25 years ago: we cannot know what "better" is until we hear it. Sometimes, I think I would rather not know. After all, I keep telling myself, there's got to be an end to this improvement business some time, hasn't there? Things can't keep getting better forever, can they? Well, can they?

At least I'm enough aware of this personal quirk that, although I will not go so far as to try and obtain samples of a new super-cable just because I have heard it may be a hair better than the absolutely perfect ones I now use, I welcome any proffered upgrades to components I currently use. It was different, however, with my SOTA Sapphire.

The Star Sapphire
Having used and loved this turntable for more than two years, I faced Rodney Herman's impending Santa Fe visit with mixed feelings. Would the latest SOTA Sapphire that he was bringing really be better than my present, familiar, reliable one? Would I have to spend a month listening to it before I could pin down its characteristics well enough to be able to judge other components without its prejudicing those judgments? Well...

Visibly, the latest-model Sapphire—the III—is indistinguishable from the original version. It doesn't even have Series III written on it anywhere. With the exception of the Supermat (which I had tried but couldn't use because the clamp wouldn't grip the short spindle of my early 'table), all the "improvements" are internal, consisting of an aluminum armboard, a hard-mounted motor assembly with a new pulley, a new platter-bearing block, and a ribbed platter with "constrained-mode" damping. (I can foresee lots of fun and games when Series I owners wishing to trade up to the new version start offering the old one for sale as the new one. Who would know? (footnote 1) And would it make any difference anyway? (footnote 2) How much better is the new one? (footnote 3)

Frankly, fitted with a Well-Tempered Arm/Ortofon MC2000 combination, there was very little difference. Yes, the Series III Sapphire gave a wider, deeper, and more stable soundstage, better inner detailing, tighter and better-controlled bass, and a generally smoother, more relaxed quality overall. That sounds like a vast improvement, but the fact is that the extent of the improvement in each area was very small. Some of it was due to the Supermat, which, in conjunction with its special clamp, constitutes the only record stabilizer I've seen that will actually make concave-dished records lie flat.

But I doubt that I would have detected the differences at all had I not lived with the original Sapphire for a long time and then auditioned the new one with familiar records. The original SOTA Sapphire set a new standard for turntable performance which had not, to my knowledge, been surpassed at under $5000 until the Series III came along, but I do not feel the difference between them to be great enough to warrant upgrading a Series I to the newest version. Not, at least, unless you feel positively compulsive about owning the very best and the very latest: the platter and motor upgrades cost $200 each; the constrained damping (done by the factory) costs $150.

But the latest Sapphire 'table wasn't all that Rod brought with him. One other item was something SOTA provocatively calls the Electronic Flywheel. This is a medium-sized Black Box, which connects between the 'table's outrigger DC supply and the 'table itself. What does it do? It filters everything but DC from the external DC power-supply source, regulates the output voltage, and doubles the available current. Okay, so we can all see what the filtering and regulation will do: they'll keep potential sources of speed fluctuation away from the drive motor. But what could twice the available current possibly buy you? I still don't have a satisfactory answer to that, because I am not sure I subscribe to the idea that varying amounts of load on the 'table, due to drag from loudly modulated passages, could vary the platter speed enough to be perceptible at any level of consciousness. On the other hand, I am not prepared to dismiss that possibility out of hand.

Particularly after having listened to what the Flywheel does.

The Electronic Flywheel isn't cheap. It sells for a respectable $300, which means it had better do some pretty impressive things to the sound. I really did not believe it could. After all, the table normally gets fed only DC, presumably with a fair amount of filtering, and I have never been able to detect any evidence whatsoever of irregular platter speed. I was fully prepared to hear no difference. But I did.

All the things I mentioned in connection with the Series III Sapphire were improved again, but by a greater amount. No way would I be prepared to say the improvements were "dramatic," but they were unmistakable. A bypass switch on the Flywheel made it easy to conduct comparisons, and to confirm that, yes, those differences were unquestionably quite audible. I have to admit that the Electronic Flywheel is worth the asking price.

SOTA admits that, under some conditions, the Flywheel won't make any difference. As long as your AC supply is clean—free from spikes, glitches, RF, and voltage fluctuations—the Flywheel should accomplish nothing. If such clean-line conditions are the norm in your household, the Electronic Flywheel could be a very expensive door stop. But even though I have never had reason to believe my AC supply was contaminated, the Flywheel effected a significant improvement in sound. Perhaps it makes sense to think of it as being like a lightning arrester: it may not be needed most of the time, but when it is you'll be glad you have it.

The other upgrade that Rod had brought was one he requested I defer listening to until I had become thoroughly familiar with the sound of the new 'table with its Black Box. This was the so-called "Star" vacuum upgrade, which replaces the entire platter, spindle, and bearing assembly with SOTA's vacuum holddown system, bringing the basic Sapphire up to full Star specification.

Now this I fully expected to bring about an appreciable improvement, particularly at the low end, because I had used Audio Technica's vacuum stabilizer for a while some years ago and had observed a tremendous improvement in all things LF. (Unfortunately, the A-T's high vacuum pressure seemed to provoke conical fracturing of the grooves in playback; it damaged a number of my discs.)

Installing the Star upgrade looks like a major operation but isn't. First, if your tonearm uses viscous damping, remove the arm and set it aside where it won't get knocked over. Then stand the whole 'table up on its motor side and remove, in this order, the platter transit screws (they have nuts on them), the large center bolt, and the three Allen-head screws around the perimeter of the bottom metal disc. The only things that require care are making sure the whole player doesn't fall over while you're unscrewing, and holding the platter in place when you remove the last Allen screw so it doesn't come out until you pull it out.

The special vacuum platter is fastened to a wooden platform in its shipping container. To unpack it, turn the container upside down (platter down), preferably on top of a sofa cushion to catch it when it comes loose, and remove all the visible screws on its bottom plate—the large center bolt last. You'll see a ¾"-thick metal disc under the platter with a T-shaped pattern of small holes in it. Line these up with the matching holes on the bottom plate of the 'table base and, being careful not to rotate the platter, insert it into the base. (This takes a slow, careful action so as not to knock the base over. An assistant holding it would be valuable insurance.) Use a large nail through the base bottom to line up the holes, align the thin metal bottom disc over them, and replace the three Allen-head bolts. In place of the original large central bolt, you must now attach the vacuum fitting provided with the upgrade kit, using a wrench to draw it firmly, but not too tightly, up against the bottom disc. Finally, replace the transit screws, drive them in until they come to a stop, then back each one out ¼" and tighten its nut against the bottom disc. Attach the free end of the vacuum tube to the nipple on its fitting, lay the 'table flat, and you're ready to connect the power-supply cables.

First, you discard the Sapphire's old DC supply and, if you already own the Flywheel, discard also the adaptor previously used to connect them together. The short cable with the multi-pin plug goes from the Flywheel to the pump, the long one (from the vacuum controller supplied) goes to the Flywheel, and the 'table's power-supply cable goes into the vacuum controller. That's all there is to it.

Well, not quite all there is to it. Because the vacuum platter is higher than the standard one—why, Rod?—you will need to readjust the height of your tonearm to preserve proper VTA. And that may pose a small problem. Because the Sapphire's tonearm board was already about 1½" below the top of its platter, my Well-Tempered Arm was close to the limit of its height adjustment before I installed the vacuum platter. The Star platter added an additional ¼" of height, and I had to slide the arm to the very top of its track to get it close to the proper VTA for my Ortofon MC-2000 cartridge; I still could not quite reach the optimal point. The solution with this particular arm was a simple one, because it has a single-hole mount: I just added a thick metal washer between the arm's pillar and its mounting board. Other arms may not be nearly so easy to shim up, and for these SOTA offers a special stepped aluminum arm board.

I fired all this up with some misgivings, as I have used vacuum devices which required a motor-driven pump in the past and, their merits notwithstanding, found I could just not tolerate the pump noise. (My listening environment is extremely quiet.) When I turned on the SOTA Sapphire system, there was not a trace of pump noise. Absolutely none. Not even with my ear pressed against the pump case! There was also no vacuum.

Some creative diddling revealed that the vacuum controller adjustment apparently had a "dead spot" at each extreme of its rotation. All the way CC, and the pump would just run out of sauce. Advance the control, and the pump could be heard speeding up until, in the fully CW position, it would cut out again. Not a serious problem, but one I told myself I would have to bear in mind in future. (And one that SOTA's instructions should address.)

I mentioned pump noise. Yes, there is some. But it was barely audible from two feet away in my quiet room, and was not audible at all from distances of more than about four feet. In short, this is the first motorized vacuum-operated audiophile device that doesn't come with a noise price attached. SOTA really did a job on this design!

Star Sound
But how did it sound? sounded fabulous. Every aspect of the sound was at least noticeably improved, by a margin that was rather significantly greater than the improvement effected by the Flywheel. Except at the low end. There the improvement with some discs almost defied belief! With others it was only very impressive, depending on their shape before the vacuum grabbed hold of them. The greatest improvement, predictably, was with discs that had bad coolie-hat dishing, when they were flipped concave-side up. These are usually real troublemakers, whose completely undamped surfaces ring like the proverbial bell, and which defy the efforts of even the most effective clamp-type stabilizers to get them to lie down and behave. (Only the Supermat will help these, and not even it can cope with the worst of them.) A few such discs, particularly badly deformed, needed to be gently pressed down with the fingers around the perimeter in order for the vacuum to grab hold, but once clamped, they stayed clamped.

From all discs, the immediate impression was of greatly improved solidity across the board. Stereo images were more tightly bunched and stable, the soundstage boundaries became more definite, and inner details I had thought were superbly reproduced before became better focused and more sharply delineated. But most dramatic was the amount of tightness, control, and extension added to the low end. Even the WTA's slight but persistent tendency toward midbass boominess at high listening levels was diminished, if not all that much. I was impressed!

Incidentally, the vacuum pressure (de-pressure?) is quite low, even at the highest setting of the controller. It is widely theorized that excessive vacuum was the reason A-T's vacuum stabilizer damaged discs. Because there was no way it could be evacuated while playing a disc, the space between the disc and the platter had to be evacuated before each play. And because there was always a certain amount of leakage during play, the initial vacuum had to be quite high so there would still be some left at the end of the side. That, apparently, was its fatal flaw.

The physical properties of vinyl relate to the presence in it of what is called a plasticizer—a volatile liquid which gives the material its flexibility. Over time, this plasticizer tends to migrate into the air, at a rate which is inversely dependent on the pressure of that air. A drastic reduction in air pressure will cause a rapid loss of plasticizer from the vinyl molecules at the disc surface, creating a brittle "skin" which will remain that way until more of the plasticizer from deeper within the vinyl migrates to the topmost layer. This may take several days, and if the depleted side is played before the plasticizer has been restored, the "skin" will be less able to dissipate surface-friction heat, and conical fracturing will be exacerbated (footnote 4).

Rod Herman claims the maximum vacuum obtainable from his system is well below the danger point, but nonetheless urges using the least vacuum you can get away with. I think he is being overly conservative. Several times, I tried playing the reverse side of non-LASTed discs immediately after playing side one with the vacuum up full, and got no more surface-noise increases than is normal: an addition of about one tick per five minutes. The amount of vacuum you use does affect the sound slightly, but it is my feeling that, regardless of what sounds best to you, anything less than maximum stabilization can only increase the amount of ringing from the disc, and that the most is the best in terms of accuracy.

Even at the maximum vacuum level, there is never the slightest perceptible resistance to the removal of a disc from the platter (partly because finger pressure at the edge of the disc breaks the seal immediately), and this may give the impression that the system isn't working. There's an easy way to check for a good seal, though: with a fingernail, gently tap the rim of the disc, diagonally from the cartridge, while playing the lead-in grooves. A dull "thud" is a sign that everything is battened down; a "pock" means it isn't, and you should check to find out why.

Incidentally, the Star system also comes with a soft rubber spindle cap, which prevents air leakage from through the center hole. I did not find this to be necessary with most discs, which is a good thing because the cap is difficult to remove, clinging so tenaciously to the disc label that it makes a little POP when it finally lets go.

Summing up the Star
All of these mods, then, are very worthwhile additions to the standard SOTA Sapphire. If you are now using a Sapphire I or II at the head of a system having high enough resolution for you to hear differences between good interconnects, all three of these upgrades (the third being the Series III mod) are well worth their not-insubstantial cost in terms of improved sound quality. The fully loaded SOTA Star Sapphire is well worth the asking price.—J. Gordon Holt

Footnote 1: By getting its serial number and telephoning SOTA to ask.—J. Gordon Holt

Footnote 2: Yes.—J. Gordon Holt

Footnote 3: Enough.—J. Gordon Holt

Footnote 4: The late Dr. Edward Catelano, founder of LAST, was first to document (with electron microscope photographs) and explain conical fracturing: Stylus/groove friction due to the very high contact pressure (several tons per square inch) causes an instantaneous drastic increase in temperature at the contact surface. As long as the vinyl is completely homogeneous, the heat is absorbed harmlessly by the underlying vinyl. Any discontinuity in the structure of the vinyl, however, will inhibit this absorption, causing the contact point to overheat and to expand to the point where it can no longer fit the space it previously occupied. As a result, a tiny conical bit of material is expelled from the groove wall, leaving a hole that forever after will produce a surface-noise click.—J. Gordon Holt