FEEDBACK ONLINE - ISSUE 33
TX-1000 Self-Centering Turntable - The Reason Behind the Legend
Amongst turntable aficionados the Nakamichi TX-1000 turntable and its smaller brother, the Dragon Computing Turntable (CT), are legendary. These turntables, like most classics, are rare. Both turntables were sold from roughly 1983 to 1987 before being killed off by the ascendancy of the CD. The TX-1000 sold in the USA for approximately $8,000 and the Dragon CT for approximately $2,000 (including a good tonearm). Estimates of the total number of these turntables sold worldwide range from 200 to 500 for the TX-1000 and 2,000 to 5,000 for the Dragon CT. These numbers are guesstimates as no one really knows for sure. While the TX-1000 and the Dragon CT are both Nakamichi turntables, they actually are quite different from one another in both design, appearance, and materials (cast metal versus wood). These differences are understandable when you realize that the TX-1000 was designed by Etsuro Nakamichi and built by Micro-Seiki, while the Dragon CT was designed by Junichi Okumura and built by Fujiya Audio Ltd. (Courtesy of www.thevintageknob.org)
Despite being so different from each other the TX-1000 and the Dragon CT share one incredible feature. Both turntables have a self-centering mechanism that eliminates the wow caused by the spindle hole being punched off center.(1) All of us who play vinyl records have seen the effect of an LP with an off-center spindle hole—the cartridge and arm swings horizontally from side to side with each revolution of the platter. Likewise, we have heard the pitch of a sustained note rise and fall with each revolution of the turntable. This is particularly noticeable on sustained piano notes contained in the last grooves of a side.
The reason for the rise and fall in pitch and its significance was explained in Dr. Robert Greene's review of the TX-1000 which appeared in issue 54 of The Absolute Sound (July/August 1988). Since Dr. Greene stated it so well, I will quote from his article which is posted at his site.
To summarize Dr. Greene, even if your LP is made with the spindle hole dead-centered, if your spindle hole is .1 mm larger in diameter than your spindle you will most likely have audible wow. Wow at this level will probably not be audible as a rising and falling pitch unless you are very sensitive to pitch instability. However, most people will notice that the inner details of the music will be blurred or indistinct. Also consider what is happening to your stereo image as the stylus is forced against first one side of the groove and then against the other side of the groove with each rotation of the LP—essentially anti-skating gone crazy. For those of us that listen to vinyl on a regular basis we are accustomed to hearing the consequences of pitch instability caused by off-centeredness. We just chalk these detriments up as just some of the inherent differences between digital and vinyl playback. This is what I thought also, until I found a TX-1000 lying on a shelf in the back storeroom of a shop where it had lain covered by dust and debris for eleven years. With some tender loving care and a lot of luck I was able to resurrect the TX-1000 and for the first time was able to hear the dramatic sonic improvement that is inherent with having the LP correctly centered.
With the TX-1000 you can play an LP without using the self-centering feature—this is called nominal centering. And you can switch back and forth between nominal and self-centered. Thus, it is easy to hear the difference self-centering makes. With an LP that is .5 mm off-center, the improvement in sound is very noticeable—more detail, a more natural, relaxed sound, and none of that annoying undulating wow on sustained notes. I never realized how much I hated that sustained note wow until it was gone. With LPs that are less than .1 mm off-centered, the sonic difference between nominal and self-centered is not very audible. However, I think I can still hear the difference down to about .06 mm, though the difference is very slight. As Dr. Greene mentioned in the quote above, the TX-1000 gives a digital readout of the off-centeredness of each LP that it centers. Very few of the hundreds of LPs that I have centered on my TX-1000 are off-center by less than .1 mm. Thus, almost all LPs that I play on my TX-1000 sound better for having been self-centered. There is no doubt in my mind that self-centering an LP can significantly improve the quality of the sound during playback. However, self-centering is meaningless if the turntable itself is not a good sounding turntable. After all, putting delicious frosting on a mediocre tasting cake is waste of good frosting.
The specifications of the TX-1000 as published by Nakamichi in early 1984 (via a Google translated Japanese sales brochure) stated the signal to noise ratio as "above 78dB DIN-B". Wow and flutter were stated at "0.003% (WRMS/FG direct reading method) 0.02% (after WRMS and the center search)". I am not an engineer and I don't know what these numbers really mean. What I do know is that as my TX-1000 is currently set up, with a Van den Hul Colibri XPW mkIII mounted on a Schroeder Reference 9" jacoba tonearm and with the turntable supported on Stillpoints rather than on its original air bladders, the sound with nominal centering is wonderful. The sound is detailed, smooth, musical, has rhythmic drive and arises from a black, black background. With self-centering, things get even better. I wish I had a Teres Certus direct drive or a Walker Proscenium belt drive turntable in my listening room so that I could do a proper A-B comparison. However, I don't. I have heard both the Certus and the Proscenium turntables at audio shows. I suspect that both turntables sound better than the TX-1000 with nominal centering. To say how much better, I would have do an actual A-B comparison. However, if the TX-1000 self-centering feature were used, I believe that I would much prefer the sound of off-centered LPs played on the TX-1000 versus the same LP played on either the Certus or the Proscenium. I admit it. I am addicted to listening to LPs that don't have pitch instability. Having lived for months with pitch stability I really would not want to go back to instability.
Now I will qualify that last statement. For rock, heavy metal and certain percussive soundtracks pitch stability or instability is not really that noticeable. For this type of music I use my Garrard 401turntable with Moerch DP-6 12" arm and Empire 750LTD (moving magnet) cartridge. I find that this combination of table, arm and cartridge to be highly synergistic and produces music that has more pace and rhythmic drive than the TX-1000, Schroeder, Colibri combination. On the other hand, for classical music, small ensembles, and vocals the TX-1000 combination is, for me, the only way to go.
Now the above two paragraphs are not much of an equipment review. Besides how many readers of this article will ever see a TX-1000 in the flesh let alone be able to purchase one? The answer is - not many. Under the guise of a review, this article is really an editorial. Vinyl is making a resurgence. New turntables are coming to market and many of them are quite expensive—much more expensive than either the TX-1000 or the Dragon CT, which would have cost roughly $16,000 and $4000, respectively, when their original purchase price is adjusted for twenty years of inflation. Modern day turntable manufacturers are reluctant to publish the flutter and wow specifications for their turntables. However, the rule of thumb is that current belt drive turntables have flutter and wow of less than .1% and current direct drive turntables have flutter and wow of less than .05%. The inexpensive ($399 street) Technics SL1200 has published flutter and wow of .035%. So let us be generous. Let us say that your new $30,000 turntable has flutter and wow of only .015%—an incredibly low number. Now you put your audiophile approved $40 LP (with the spindle hole being .25mm off center) on your new turntable. Per Dr. Green's figures above, your flutter and wow just went up to .345% (.015% from the turntable and .33% from the off centered spindle hole). The manufacturer of your turntable just spent $1 million in research and development to bring the flutter and wow down to an incredibly low .015% and you just paid a portion of that R & D with your purchase. My question to you and the manufacturer is: Who cares if flutter and wow of the turntable is .015%? What is important is not the flutter and wow of the turntable by itself, but the flutter and wow of the turntable and LP combined. If the flutter and wow of the turntable was .05% that would mean the flutter and wow of the turntable with the LP would be .380% (.05% + .33%). Audibly, .380% is not much different from .345%. The difference between .380% and .345% may not even be audible because the .035% difference is being swamped by the .33% LP wow. To my way of thinking, the purchaser of a turntable would be far better off if the turntable manufacturer spent his R & D money on developing a self-centering mechanism for his turntable. That would dramatically lower flutter and wow on playback for the purchaser of the turntable. Who listens to a turntable spin with no record on it? What is important is the flutter and wow with the LP spinning and the stylus in the groove. This is the real world situation. Even if all of our LPs were off center by only .1 mm and all spindle holes were the exact diameter of the spindle, neither of which is the case, the .380% versus .345% flutter and wow would only drop to .180% versus .145%. This is still audible and the LP flutter and wow is still dominating the turntable flutter and wow.
So what does all this mean for the average vinyl lover. It means nothing if you are not going to buy a new turntable at some time in the future. However, if you might be buying that one last turntable some time in the future you might want to have a little chat on the phone or at the next audio show with your favorite turntable manufacturer. You might want to give him copy of Dr. Green's article and point out to him that while Mr. Manufacturer is spending all his time trying to drop his flutter and wow from .05% to .04%, there is a 400 kg gorilla rampaging though the listening room that is making so much noise that all of Mr. Manufacturer's time and money spent on achieving a .04% flutter and wow is meaningless and wasted. If enough of us talk about self-centering, maybe one manufacturer will actually do it. And if one manufacturer does it, many more will follow due to competitive pressure. If a dealer is demoing a self-centering turntable and a non-self-centering table and the tables are anywhere close in price, I believe the customer will choose the self-centering turntable the majority of the time. Building a self-centering mechanism is not as difficult or as expensive as it was in the 1980s. With current micro processors and servo motors the design and manufacturing of a self-centering turntable is easier and cheaper (in inflation adjusted dollars) than ever before.
If you love listening to your vinyl, do yourself and the rest of us vinyl lovers a favor and talk to turntable manufacturers about getting rid of the 400 kg gorilla and giving us true pitch stability by building a self-centering function into their turntables.