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by Stephen W. Watkinson
SOTA VACUUM SUPER MAT & ELECTRONIC FLYWHEEL
SOTA VACUUM SUPERMAT
Two-piece turntable mat for SOTA vacuum turntables.
Price: $150.
SOTA ELECTRONIC FLYWHEEL
Solid-state power supply filter and regulator, for use with SOTA turntables.
Price: $300. MANUFACTURER: SOTA Industries, P.O. Box 7075. Berkeley, CA 94707 Telephone (415)632-0394.
I long ago ceased to be amazed at the lengths to which audiophiles will go to achieve perfection, or something close to it. To the uninitiated, it must seem deranged to spend what amounts to the monthly payment on a new BMW for two small items that make what can be described as, at best, a modest improvement in sound quality. Of course, being an audiophile, it seems perfectly logical to me. These two SOTA accessories fall in the category of "needed" system improvements that cause non-audiophile spouses and friends to think you crazy. They make a noticeable, though minor, improvement; they lift one more veil, bring your system one step closer to perfection.
After reviewing SOTA's standard Super mat (Vol. 8, No. 3), I was eager to try the vacuum version. I must confess to some disappointment in the limited improvement it made. I suspect that much of the improvement afforded by the standard Supermat results from its unique "Herman curve" (the slightly convex surface of the mat, developed by Rodney Herman) and effective clamping system, which allow the record to be pressed tightly against the mat-something already accomplished with the vacuum clamping system of the Star Sapphire. Thus, the improvement offered by the vacuum Supermat results ex elusively from the inherent qualities of the mat, not the increased intimacy of disc contact.
Like the standard Supermat, the vacuum Supermat consists of two pieces: a hard acrylic top mat and a soft, compliant inner mat. The hard top mat fits into a lip on the outer edge of the inner mat. The inner mat's lip rises up over the outer edge of the top mat to serve as the sealer gasket for maintenance of vacuum. The glazed texture of the acrylic top mat over the black inner mat resembles the surface of a frozen pond. Unlike the standard SOTA Supermat, which is compatible with most conventional turntables, the vacuum Supermat can be used only with SOTA vacuum 'tables.
The vacuum Supermat makes several subtle changes in the sound. Most of these changes are clear improvements, but some may not be beneficial on certain systems.
On the unquestionably positive side is better high frequency performance. At first I thought the mat was extending the frequency response at the top end. After more careful listening, however, I began to doubt my original conclusion; the highs were no more prominent than before. They were simply cleaner and clearer. I was hearing more detail, less extraneous noise. Detail also improved slightly in the midrange. The difference was less noticeable than in the upper octaves, but was still an unmistakable improvement.
The vacuum Supermat also made a rather unusual improvement in the soundstage: the height of microphone placement be came much easier to discern. With the Supermat, one hears the performance on simply miked recordings from the perspective of the microphone, making soundstage height more realistic. The improved HF performance also seemed to make specificity of HF sound sources slightly better.
SOTA claims that the vacuum Supermat also improves the soundstage width and depth, and provides better segregation of individual instruments. I noticed no improvement in these areas on my reference system.
The value of one change occasioned by the vacuum Supermat is system-dependent: it produces a slightly warmer overall sound, caused, I suspect, by a simple amplitude increase in the lower midrange and upper bass. On a system that sounds thin or analytical, this will generally be an improvement, but might be too warm on well-balanced or slightly "musical" systems.' The Supermat also cleaned up the very low bass region, providing much better detail in the bottom octave.
Perhaps the best evidence of the vacuum Supermat's value is its ability to reveal the problems which plague all too many records. The increased detail and cleaner bottom octave show that not only are most records not flat (a problem solved by the vacuum turntable), many are not of uni form thickness. Also, I kneu. there was a lot of garbage in the bottom octave of many records, particularly those of European origin, but the vacuum Supermat and the Dayton Wright ICBM subwoofers disclosed that I had underestimated the enormity of the problem. Dutch pressings of British Decca recordings were the worst (or at least the most consistent) culprits.
In contrast to my mild disappointment at the modest improvement made by the vacuum Supermat. I was pleasantly surprised by the Electronic Flywheel. I have always been in the camp that believes that powerline conditioning is beneficial: all of my equipment is isolated from the house AC by high-current computer-grade filters.
You have to be intimately familiar with the system, though, to notice the improvement in sound quality made by such devices.
Also, their benefits seem to depend on the time of day: on a midsummer afternoon, with air-conditioners running and factories working, an improvement can be heard; at 2:00 AM on a pleasant fall night there seems to be none. ,
-------------------- 1. To some extent the increased upper bass and lower midrange energy can be ameliorated by increasing the amount of vacuum. In fact, regardless of the other components used. I found that a slight increase in vacuum when using the Supermat compared to the level used with the standard mat) improved the sound.
2. The better line current in the wee hours of the morning may explain why many audiophiles find their system sounds hest late at night. Of course. a few glasses of brandy may also help things along.
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The SOTA 'tables use servo motors which should not, in theory, be as susceptible to irregularities in house current as the synchronous variety. Therefore, I expected any improvement made by the Electronic Fly wheel to be very slight and hard to detect.
I also anticipated that friends who heard my system only every few weeks would be unable to hear the difference.
I was wrong. The effect of the Flywheel is easy to detect on high-resolution systems, and is, without a doubt, an improvement. I picked up the Flywheel at the SOTA factory while on a trip to the San Francisco area. It was presented to me as something that might make a very slight improvement, especially if I lived in an area with line-current problems; it was clear that Rod Herman believed the vacuum Supermat would be the more prized up grade. Later that day, while visiting a manufacturer in the Bay area who uses a SOTA 'table as his reference, I mentioned picking up the Flywheel. He snickered. We nevertheless decided to give it a try in his sys tem-and were both startled at the degree of the improvement! The change was not dramatic, or of the scale of a major system upgrade, but it's more than a fine-tuning tweak. The improvement manifests itself as a sense of purity of tone and detail. Sustained notes, particularly on piano, are the best example.
Not so obvious is tighter bass, and better separation of massed instruments in orchestras, particularly the higher strings.
For example, acoustic bass on jazz recordings sounded tighter and better focused. In symphonic works, the attack of the double basses had a more distinct "dig." The better separation was also noticeable on choral works, individual voices being easier to discern.
The Flywheel did not affect the tonal balance or general character of the sound, not as if you had changed components.
Rather, it seemed as if the system had been thoroughly fine-tuned from top to bottom.
The Electronic Flywheel is a must for SOTA owners with high-resolution systems. With the possible exception of put ting Tweek on your contacts, I can't think of a better improvement you can make to your system for the price. The only bad news is that the Flywheel breaks with the SOTA tradition of universal upward compatibility. Older SOTA models with an internal power supply (those made before mid-1982) won't accept the Flywheel.
These older SOTA’s can be converted to the external power supply, but the cost is $200, plus freight to the factory. That brings the total cost to over $400, and I suspect there are greater improvements you can make to your system for that amount of money.
I can also recommend the vacuum Super mat as a worthwhile and cost-effective upgrade for owners of the SOTA vacuum 'table, but the Star Sapphire is already so good at disc damping that the improvement wrought by the vacuum Supermat is somehow less compelling. There's also the caveat that in some systems the added lower midrange and upper bass warmth might prove undesirable.
--
[based on a March 1986, Stereophile review article]
Also see:
THE WIN MC CARTRIDGE AND PREAMP
THE CONRAD JOHNSON MV-50 AMPLIFIER
THE NEC CD-705E COMPACT DISC PLAYER
THE INFINITY IRS-III AND RS-IB: STILL FURTHER CONSIDERATIONS
THE RAUNA TYR MARK II LOUDSPEAKER
THE SYNTHESIS LM-20 AND LM-250: A NEW LINE OF TOP QUALITY SPEAKERS
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