Is Direct Drive Really Better?

Isn't that backwards? If the lathe slows and the playback turntable also slows, aren't you re-doubling the problem rather than adapting to it?

Raul: I think your focus on speed-accuracy may be overstated. IMO speed-stability is the more important factor, beyond a certain point of competence concerning accuracy. Accuracy isn't that hard to achieve, stability is.

Caterham1700: Those figures would appear to confirm that implementation is a lot more important than classification, but it would be nice to know exactly what those numbers represent of terms of how the test was made and the data assessed. I continue to strongly suspect that the *nature* of a TT's speed distortion has got to be at least as important as its overall percentage level, just as in amplifier harmonic distortion. And that beyond some minimum level of speed-stability competence, resonant behavior might be more sonically significant.

Teres' last post prompted a thought: In theory, shouldn't the ultimate goal for transcribing what's on a record be to duplicate whatever speed distortions are inscribed in the grooves by the cutting lathe? If a TT slows a bit when it encounters increased stylus drag, then a lathe must also slow when it cuts more highly modulated passages into the blank lacquer. To read the information as accurately as possible, the playback should read those grooves with speed distortions that correlate with how it was cut. This would seem to be argument in favor of regarding dynamic stylus drag in TT's as being more benign than is usually supposed, perhaps even beneficial in the right porportion.

Back in the day,Audio magazine regularly performed Speed stability specifications for their reviews-

Belt drives-

Linn LP12 : ±0,385
Maplenoll Ariadne : ± 0,20%
Michell Gyrodec : ±0,12 %
Oracle : ± 0,213%
SOTA Sapphire : ±0,18%
Thorens TD115 : ±0,27%

Direct drives-

Nakamichi Dragon : ±0,13%
Goldmund ST4 : ±0,317%
Technics SP-10 : ±0,19%

Dear friends: The Macrojack start thread question: " Is Direct Drive Really Better? ", it is an open question that has several different stages. Because of that I think there is no single answer of the question.
If we read all the ones posted here in some ways all of them are right answers.

In my opinion we have, at least, two big stages about: one an objective aproach and the other a subjective one and from here we could have another stages like a: objective/subjective one.

From the objective approach what will be tell us which drive TT design is better are: MEASUREMENTS that could be corroborated in a scientific way. What should be measured?, at least: speed accuracy, speed stability ( refered to time ), signal to noise, rumble and woow&flutter.
From the information that I have the DD designs are the ones where we can find almost all those measurements. In the BD designs we can find little info about and in the IW less info.
So with out those measurements info we can't say for sure which drive TT design is better. I posted that the speed accuracy of the SP 10 ( 0.001% ) beats any BD design because searching info about I find that the Walker is 0.002% and the Commtinum 0.006%, but I can't find any info on: Basis, VPI, Teres, Galibier, Simon Yorke, Clearaudio, Transrotor, Brinckman, etc, etc..
Now, for IW the very little info about is really poor.

I have a lot of respect for Johnnantais and when he told us that the IW drive system has a better speed accuracy/stability he don't have a scientific measurement where all of us can corroborate that. So from an objective approach the Johnnantais opinion ( like mine or other people ) has no value at all and can't tell us which drive system is better.
The same is for the " tonearm/cartridge drag " subject: till today nobody can confirm which drive system ( high mass platter or not ) is really better on this subject. All we have are opinions, that's all.

Btw, from the objective approach I think that it is time that the BD and IW defender take their time and money for to have those objective measurements. Johnnantais this is part of your challenge where you can prove you point of view.

Now, if we take the subjective approach then things could be extremely complicated because any one of us could have a different opinion about. Here there is not only our opinion but in which stage are our opinion corroborated, that is, against what: what we like it or against live music?, in which room, with which tonearm/cartridge, which cables, which phonopreamp, wood/acrylic/metal design, air bearing or not, vacuum hold down record?, which mat, which clamp type, which load impedance, VTF/SRA, which records, which speakers, full range system or not, which, which, which and which?, no ended.

With the info that I have ( objective approach ) I confirm that the DD design is the best one. If any of you want to prove that other drive TT designs are better you have to prove it with those measurements not with an opinion, this opinion belongs to the subjective approach and here any of us could be " right ".

Regards and enjoy the music.
Raul.

Jack .. there's a Technics SL-1000 (consumer version) and a couple of SP10 Mk2s on ebay right now, for between $400 (no plinth) to $800 (plinth and arm).

I vote you buy one and report back to us in a month or so :-)

I don't purport to know anything about idler wheel drive systems and I would be very open to trying one. My principle hesitations are first that I wouldn't know how to acquire a Lenco and I don't have any mechanical skills whatsoever. Mounting a cartridge is on the outer reaches of my adroitness so the prospect of keeping a mechanically complex drive system operational appears discouraging.
What do you say to people like me?

John, I have not personally argued that belt drive is superior. I would truly love to hear a 3 way shootout between a Lenco, an SP-10, and a Teres, Galibier or similar belt drive. I haven't the time, the will or the money to do so.

I have read posts from many who say the Lenco is the best. I have also read posts from people who have heard Lorricraft Garrards and like the bass, but find them lacking in subtlety and detail in comparison to a Nottingham Hyperspace.

I fully agree that your ears are what matters. You should buy what sounds best to you. What I DO NOT agree with is that you are able to declare the Lenco the best turntable, because you and some others like the sound the best. Does this prove that it has the best speed stability ? Not at all, it proves that you like the sound best.

My experience is that the torture test for speed stability is solo piano, preferably a slow movement, like a Beethoven sonata. Yet whenever people describe the strengths of the Lenco or Garrard the first word is always BASS. That does not correlate with my personal experience where a turntable can produce articulate and deep bass, but have terrible speed stability when it is introduced to solo piano.

So, in summary, there may not be a one-size-fits all best in terms of what sounds the best, because we all have different interpretations. There may be a best in terms of measured performance, but using your ears might not be a good way to come to a conclusion.

I see here a lot of simple prejudice: belt-drivers argue what things "should" sound like and why certain aspects "should not" make any difference, in the absence of having seriously tested and heard the alternatives, if at all. These defend their system simply because they own them and not the alternatives. Direct drivers - like Psychic animal - continue to declare DD the best, in the absence of having heard idler-wheel drives, though they feel free to make use of my findings and reasoning, to defend their own system, which they have invested in. In the absence of having heard the alternatives, like belt-drivers, they prepare to make major investments in their chosen system. Chris Brady continues to casually lump idler-wheel drives with belt-drives in the Inferiority Sweepstakes, again I suspect in the absence of having heard the reality, and he is coincidentally preparing to release a DD.

Theories must be tested empirically to verify the truth of a matter: if experiment contradicts a theory (i.e. proves it wrong), then theory must be abandoned or seriously altered. What I wrote up above: "Then there is your message here - "The best of our efforts will compete with turntables costing many times more, and we have friends that can attest to this fact. In some ways, they sound better, especially in the lower end and in that indefinable “pleasure” factor. I am neither an engineer nor a psychologist so I will not try to explain the “boogie factor” these tables seem to have." The fact that you can hear this, and it is repeatable from Lenco to Lenco despite differences in plinth materials, design and weight, points to something in the Lenco proper which accounts for this: it is superior speed stability, which in its turn underlines lack of same in belt-drives. It is, being audible, an empirical fact, and being audible there is a physical reason for it, no need for psychology beyond the human ear's EXTREME sensitivity to pitch (speed stability). It has speed stability which is superior to that of the belt-drives you have heard or compared it to." What Chris Brady then posted: "I have concluded that speed stability is one of the most important factors in turntable sound quality. For that matter it is also one of the key performance factors in digital audio. It is well known and accepted that digital jitter significantly degrades sound quality. What is remarkable about digital jitter is that such extraordinarily small timing errors could be audible at all. The message here is that our ears are far more sensitive to timing errors than with amplitude errors. With analog the principle and effects of jitter/timing errors are essentially the same. In both cases waveforms are being reconstructed and timing errors create similar distortions. Distortions that for some reason are much more audible than one might expect." Same thing, I have known about this since I frst heard an idler-wheel drive and have been promoting it ever since: i.e. I was confronted by the evidence, which is why I harp on about empirical science and experiment, not on-paper theories, which must bow to empirical realities, and not lead them.

Those who continue to blindly promote their own systems in the absence of experience are cheating themselves of an ear-opening experience, and those who invest in a system in the absence of context may find themselves backing the wrong horse, find themselves in financial difficulties, and with serious egg on their faces. Consider the following scenario: with much foofarah an expensive DD is released on the market, and a DIY Lenco shows up which simply crushes it at an audio show, thus crushing any hope for a financial future. Now you may doubt this, but such demonstrations are coming, and you'd better be prepared. I advise you to listen to the alternatives (making every effort to optimize and not rig the experiment by casually and sloppily setting up one system and perfecting the other) before making any decisions. Now, when I was converted to idler-wheel drive, I already owned two highly-regarded belt-drives, I had no reason to convert (in fact the reverse considering the investment in expensive belt-drives). I went out of my way to purchase and restore a Technics SP10 MKII, one of the best DDs ever made, and compare it to the Lencos. The differences were not small, and I have since heard comparisons several times. I have also tried several other heavy statement DDs. Has anyone here done the same?

From a similar discussion a year ago:

"In a word, the sound is "magical", and because, in two words: "speed stability". I will here plagiarize my own text under my "system": "The idler-wheel-drive Garrard 301 grease-bearing was the 'table used by Sugano in the design of his Koetsus, and the Lencos are far easier to repair and restore, and may in fact sound better (more refined while preserving the traditional idler-wheel strengths of unparalleled attack and bass speed and power), for a variety of reasons. Idler wheel drives in general were originally designed to overcome stylus force drag, as in their day cartridges tracked at 10 grams. As tracking forces diminished, idler-wheel drives became more refined, but retained their resistance to stylus drag. As time went on and VTF dropped to below 2 grams, it was thought stylus drag could be combated by the simple use of mass, and not the brute force of rumbly idler-wheel drives, which were discredited, even though their rumble figures were in fact better than those of the then-rising Linn LP12. If you remember your history, you will remember that CD as well was touted by the majority of the press and the industry as superior to the previous technology, vinyl. The Lencos do not rumble, and they prove that in fact it does take a certain amount of (refined) brute force to counteract the all-too-audible problem of stylus drag, which belt-drives are ill-equipped to combat, their Achilles Heel being their belts and weak motors. This is clearly audible in the attack of a Lenco (or large Garrard), the tremendous bass reach (bottomless) and bass detail of a Lenco (which affects both air and imaging), and of course its perfect timing and speed stability under real-world conditions (actually playing a record)."

Now I do not tout the Lenco and the idler-wheel technology it represents merely because I own one, I also own or have owned both high-end belt-drives (Maplenoll Ariadne, Audiomeca) and direct-drives (Technics SP10 MKII, Sony 2250) and a host of others, and so I have actually bought and owned the various drive systems available out there, at very high levels of performance: and the Lenco beats them all by a wide margin, which you should pause to think about, given the Law of Diminishing Returns (should high-end 'tables be so easily and completely and without sonic price beaten?). I am being very scientific, enlisting the world in a global empirical experiment, to decide the issue of which drive system is in fact better. Now while it is politically correct and nicey-nicey to go around saying there is no superior system and it is a matter of taste because there are always compromises and so forth, I say that's all very well, but is it true? Is no system in fact superior? Participants from around the world have declared the Lenco superior to a host of current high-end belt-drives which they in fact owned, and so like me had no reason to declare inferior. The experiment continues. It's cheap to participate and have fun with it! Cost of entry is minimal, give it a try!"

And before you proceed to crucify me, remember my messsage is simple: I do not blindly claim the Lenco is the best, I challenge the world to hear one for themselves and let their ears decide, I put my money where my mouth is, and I make gargantuan efforts to help people in the execution of the experiment so they can decide for themselves. My message is simply : try it first, and THEN decide. This is the heart of empirical science, the search for truth. Or you can continue to argue the superiority of your systems without actually investigating them.

Good enough that a direct drive offering from Teres is in the works.

I've said before and it is in the archives: the Teres is a direct drive in drag.

With psychic power and primal intensity,

About stylus drag. I am unaware of anyone who has actually measured it and can certainly agree that it seems far fetched. However, we should not underestimate the audibility of timing errors. Digital jitter on the order of tens of picoseconds has been shown to be audible. A pico second is one trillionth of second! At the 44 Khz sampling rate this is less than one part in a billion. It's easy to imagine that 2 grams of tracking force might have a one part in a billion effect even with a 100 pound platter. Measuring such a small effect would be difficult but not impossible.

4yanx, I have never thought of myself or my customers as being supporters of belt drive. It's what we have used and it has and continues to be a very good drive system. I suspect that our customers are not married to a particular methodology and will accept whatever delivers the best sound. But I hasten to add that Teres Audio is NOT abandoning belt drive. The new Teres DD setup will be considerably more expensive to produce and required a much bigger development investment. And while it does deliver considerably better performance it does so at a price. I think it unlikely that we will ever be able to come up with DD system that will compete, at the same price point, with our current belt drive motors. Of course we will try, but don't hold your breath.

So is DD superior? I think that the answer can only be yes and no. When it comes to the best money can buy, then yes I believe that DD has the potential for performance that cannot be matched with either belt or idler drive. But be prepared to spend a lot to get there. When it comes to more reasonably priced turntables then it comes down to the quality of implementation and also personal tastes. As a generality I think that belt drive tends to offer better sound for the money at all but the highest price points.

I would add, at what point does the stylus drag and micro speed variations in a high end turntable fall below the speed stability of

a) The cutting lathe
b) The master tape recorder
c) The 2" multi-track tape source

so that the turntable is now more accurate than the LP it is playing ?

I must admit Chris's post comparing analog speed variation to timing jitter in digital is quite thought provoking ... I'd never thought of them in the same way, but in retrospect it's obvious that they cause similar distortions to the waveform.

"For that question to be meaningful one would also have to know what the threshold of perception is for this phenomena. Measuring something is often easy. Correlating that measurement to perceived differences is often fraught with difficulty."

True, and not true. It is still a valid question, because I hear many people refer to stylus drag, but nobody offering proof that is it
a) Occuring measurably
b) Occuring at a level that we might expect the ear to be able to resolve.

Digital jitter has been accurately measured, and then somewhat correlated with audible effects. It's not too unreasonable to expect turntable manufacturers to do the same ?

Since Teres makes one of the leading belt drive tables and has made quite a name for itself in so doing, I would say that their announcement weighs heavily in favor of DD superiority.
Again the question ------ at what price point?
Like Viridian, I value actual experience over projections and calculations and I suspect Chris at Teres has experimented with and tested turntables more in the last several years than all of us put together. For him to change directions so radically, I have to assume that he found more than just a likelihood that DD has greater potential than the belt drive with which he has enjoyed so much success.

Mr. Chris Brady, you are obviously free to develop and produce any type of table you wish (I am all for research and development), and you may not know the answer to this question, but do you know how the owners of your current belt drive tables feel about the development of a direct drive table as your top-o-the-line model (assuming that means it’ll be the BEST table you'll make)? I only ask because I know from experience on this and other boards that many of the Teres owners are some of the most ardent supporters regarding the superiority of belt drives, in general, and of Teres tables as a leading example of same, in particular.

Jejune, Not even close to the 1200. The Teres DD table will be flagship offering. It's both difficult and expensive to do DD right.

I thought the big belt drive Teres tables were flagships. If this DD thing is even more expensive then mebbe the 4yanx was right but sooner than he thought.

Is there a paper anywhere that has measured the effects of stylus drag on a turntable with a massive platter ? It seems almost infeasible that a 2gram tracking stylus would have any perceptible effect on 10+lbs of spinning platter.

Dan_ed, We have an early prototype now and hope to have a better version in time for the open house.

Jejune, Not even close to the 1200. The Teres DD table will be flagship offering. It's both difficult and expensive to do DD right.

Gosh and we thought that digital wasn't as good as analogue! Why digital even manages to 'create' the same speed problems as vinyl LP turntables, as jitter!
Bob P.

Will the Teres offering be anywhere near the 1200 price point?

Chris,

do you think you'll have a DD prototype ready for next month's open house? That would make for some more fun!

Turntables drive systems is an interesting topic and one that I have been contemplating and experimenting with a great deal lately.

I have concluded that speed stability is one of the most important factors in turntable sound quality. For that matter it is also one of the key performance factors in digital audio. It is well known and accepted that digital jitter significantly degrades sound quality. What is remarkable about digital jitter is that such extraordinarily small timing errors could be audible at all. The message here is that our ears are far more sensitive to timing errors than with amplitude errors. With analog the principle and effects of jitter/timing errors are essentially the same. In both cases waveforms are being reconstructed and timing errors create similar distortions. Distortions that for some reason are much more audible than one might expect.

So when it comes to turntable speed stability it is a much more complex issue than many would think. Technically there is no such thing as “constant speed”. Any drive system will have micro variations in speed. As with digital jitter, both the frequency and amplitude of these variations are important. Wow and flutter measurements only quantify large, low frequency variations and don't seem to correlate well with sound.

The main source of speed variation is the motor. All motors cog, or have variations in torque as they rotate. The correct term is torque ripple. In general it is beneficial to isolate the torque ripple to reduce the effect it has on platter speed. Belts and idler wheels provide some degree of isolation. How much of course depends on how compliant the material is. At the same time it is beneficial to have the motor tightly coupled to the platter and rely on the motors torque to keep the platter speed constant. Tight coupling of the motor is best way to reduce the effects of stylus drag. So we have two opposing objectives, coupling and isolation. It would seem that for any motor, platter combination there would be an ideal compromise between isolation and coupling. For example AC motors have a lot of torque ripple so the best compromise is usually a lot of isolation using a stretchy belt. DC motors have far less torque ripple so they typically sound better when used with more rigid coupling (½ tape). With direct drive there is no isolation so the torque ripple must be very low to get acceptable sound.

Beyond the isolation and coupling issue belt and idler drives are both are susceptible to oscillation. We end up with two rotating masses connected with a compliant medium. The worst case is when both the motor and the platter have the same inertia. At first glance it would seem that the inertias are quite different. However, the motor typically spins much faster than the platter so that the inertia actually ends up being similar despite very different mass. Increasing platter mass and decreasing motor inertia helps reduce oscillation. I believe that this is one of the reasons that heavy platters tend to sound better.

As I said earlier both the frequency and amplitude of speed variations is important. There is considerable evidence that very small, higher frequency variations are particularly audible. Power regenerators for AC motors and batteries for DC motors have consistently provided better sound. My own experimentations has also shown that efforts to reduce high frequency noise results in better sound. This would indicate that higher frequency speed variations are more detrimental to good sound. This kind of error sounds remarkably like digital jitter. It sounds harsh, edgy and smeared. Not an artifact that would typically be attributed to speed stability.

Various techniques may be used to reduce these effects but they are never completely eliminated. A heavy platter will reduce high frequency variations more than a light platter. However, lower frequency problems are less effected. For example the effect of stylus drag is different but not less with a heavy vs. light platter. With a light platter a heavily modulated passage will reduce the speed but because of low inertia it will quickly recover. On the other hand a heavy plater will be slowed less but it will take longer for the speed to recover. So platter mass only changes the frequency of stylus drag effect and does not eliminate it. However, it would seem that lower frequency variations from a heavy platter would generally be more benign.

So after all the ramblings the question is what is the best approach? As many have surmised it mostly boils down to implementation. It also is a matter of compromises. Some will prefer one set of compromises over another based on their tastes. However, I do believe that direct drive has the greatest potential. With careful design and implementation direct drive can result in less compromises. With sufficiently low torque ripple and noise the results are remarkably good. Good enough that a direct drive offering from Teres is in the works.

Here's something that's always made me wonder. Folks talk about quartz/PLL-controlled DD as constantly "hunting" for the correct speed, or attempting to compensate for deviations after they've happened.

What I'd like to know is this: In a BD, I'd assume that the "kick and coast" action of the motor, or any dynamic drag flucuation caused to the platter, would cause the elastic belt to be stretched a bit on one side and relaxed on the other, because then the drive-pulley and the platter would be turning at slightly different speeds. The belt of course would attempt to regain a state of equilibrium in tension, but this would set up an oscillation between sides that would take a while to die out, before which another disturbing discrepancy would have come along, etc. So the belt would constantly be in a state of "hunting" for the correct speed, n'est-ce pas?

On an SL-1200 there is a built-in strobe, so you can see speed deviation and recovery behavior. If you use your finger or a brush to momentarily apply some extra friction to the turning platter (enough to noticably slow the platter -- in other words hundreds of times more friction than a stylus playing a record could ever apply), it will come back up to speed in a controlled, deliberate fashion without visible overshoot or oscillation.

If you put a strobe on a BD and do the same thing, does it appear to behave the same way, or is there some degree of "bouncing around" visible in its recovery behavior? This may be a "trick" question -- any differences might well be too small and/or fast to be visible either way.

I don't think a SL-1200 has a "looser bearing structure" than a BD. I haven't used an SP-10 in over 20 years though, and never looked under the hood of one.

The Mk.II pictures on this page, though clearly not the same as my SL-1200, still look to me as if there is a conventional central bearing and no drive-shaft. But on this one, there is a difference noted between the SP-10 Mk.II and Mk.III, with the Mk.II described as having an enclosed motor with what sounds like a sub-platter, vs. the Mk.III's construction which is more similar to the SL-1200.

It's still not clear to me, however, whether in the Mk.II the power is actually applied to a drive-shaft, or whether there is more than one central bearing. My assumption is that in any case where torque is transmitted via a shaft, there must be at least two bearings (as in a BD TT, a motor bearing and a platter bearing).

I'm inclined to view the subplatter as being a part of the top platter, and regard the spindle shaft as not being called upon to transmit the twisting force, but I could be wrong, or the difference could be mostly academic. Maybe the more important point is that the motor turns at a low 1:1 speed (33 1/3 or 45 RPM) and is a rigid part of the chassis. The latter means there can be no relative motion between the motor and the platter. The former means torque will be naturally high and vibration naturally low.

Here is an archived thread that has some more interesting comments, including from Twl.

Zaikesman,
My SP-10 MK II has a motor assembly with a top plate and the platter is fastened to that top plate by 3 flat head screws. On my SL 1100A, the arrangement is similar but the platter simply rests on the top plate without any fasteners. I also have an SL 150 MK II and that is similar to what you describe in the 1200 where the platter is an integral part of the motor.
The question remains however whether these DD models remain perfectly concentric in response to stylus drag or are spun off kilter by their looser bearings structures. I think that was what TWL was saying.
I questioned him about this because it appears that my DD tables are not vulnerable in the way he described. Maybe they are.
I also have a Luxman PD 441 and it has a magnetic mechanism which reduces the platter weight on the bearing by 80%. Is this better or worse in relation to Tom's premise?

Hold up, I think both both TWL and Macrojack have a couple things wrong here (not that I don't agree with most of the gist of what Tom has said -- I think I said some of the same stuff myself above :-)

"...direct drive motors generally (and I use that word advisedly) use their drive shaft as the main bearing, which typically does not have the precision tolerances of a belt-drive system's main bearing..."

I believe this is a common misconception, which I talked about in my first post to this thread. I may not always know about "generally", but specifically, a DD like my SL-1200 >>does not have a drive shaft<<. The main bearing is similar to the main bearing in any conventional BD, passive meaning unpowered. The motive force to rotate the platter is applied purely by touchless electro-magnetic impulse -- no shafts, wheels or of course belts involved. (Please also see my first post.)

"...Upon looking at the design of my Technics DD, I see that there is no main bearing per se but rather a broad based rotor/stator interface. The notion of that being rocked or deviated from its center seems remote given its diameter, mass and magnetic hold. After all it isn't a pencil point on a hard disk balancing a 12 inch diameter spinning disk. With the Technics table the motor is about 4 inches in diameter and in the case of the SP-10 it is screwed to the motor assembly..."

I think maybe you're being fooled by the appearance of the TT with the platter off. If the SP-10 is anything like an SL-1200, the platter fits over the conically-tapered brass sleeve which forms the base of the spindle, which is integral to the main bearing. When you remove the platter, the spindle is therefore left behind -- you can rotate it by hand. That is the main bearing. What you're describing as 4" in diameter is the stator assembly, which is not "screwed to the motor assembly" as you put it (not sure if you meant to write it that way, since it does't make much semantic sense), but bolted to the cast aluminum chassis, the bearing housing of which you can see centrally located within the stator ring at the base of the spindle/bearing. (Again, if it's anything like the SL-1200 -- please let me know if I am wrong in anyway in translating this arrangement to the SL-10.)

I would recommend anyone fuzzy about the details who really wants to get a feel for how this works to take a trip down to your local pro-sound shop that sells DJ gear and ask to see their display SL-1200 with its platter removed. (With the power turned off, place thumbs or fingers in the opposing holes provided for this purpose, alternate gently lifting one side and then the other to unseat and then carefully lift straight up). Everything I'm talking about should become very clear.

TWL -- Glad you could make it. Upon looking at the design of my Technics DD, I see that there is no main bearing per se but rather a broad based rotor/stator interface. The notion of that being rocked or deviated from its center seems remote given its diameter, mass and magnetic hold. After all it isn't a pencil point on a hard disk balancing a 12 inch diameter spinning disk. With the Technics table the motor is about 4 inches in diameter and in the case of the SP-10 it is screwed to the motor assembly. Very stable.
I also wonder to what extent the gyroscope effect might assist in stability in both designs. Does the platter spin too slowly for that to be meaningful. I have observed that a spinning top is rather stable at high speeds but loses that stability as its rotation slows. Does diameter of the top add to its stability to overcome slowing? Is 33 1/3 fast enough to have this influence?
Time for Seandtaylor and the physicists to come back to the discussion. I'm just tossing out questions that I can't answer.

David12, if I read your post correctly, you seem to be saying that the Garrards are direct-drive (DD) turntables. They're idler drives.

If I may be permitted to point out something that seems to have been missed here, there is more to a turntable than speed stability, although speed stability is a very important requirement.

Another factor which comes into play is the effect of vibrations or other potential movements in the main bearing assembly(and thus the platter).

If stylus drag can affect the speed stability of a heavy platter or even a motor's torque, then it can also generate lateral movements of similar proportions, due to the angular nature of it's movements as it traces the groove. Externally generated vibrations can affect this also. Since any lateral movement allowed by the bearing/platter can materially affect the amplitude of the groove modulation being traced at the time of that movement, it can cause information loss or modification, based on that unwanted movement of the platter relative to the stylus. But wait, you say, the arm could be moved more easily because it has less mass, and I say that if the arm deflects, then you get similar information distortion as well.

Now, how does this affect our discussion?
Quite simply because direct drive motors generally(and I use that word advisedly) use their drive shaft as the main bearing, which typically does not have the precision tolerances of a belt-drive system's main bearing in a good turntable. In addition, making the platter part of a motor which has inherent vibrations as a natural characteristic is not conducive to ideal conditions for the stylus/groove relationship.
So, even if a direct drive does exhibit a slightly better measured speed stability, there are other factors involved besides that.

Also, wow and flutter are very different speed variations, and to lump them together as "wow and flutter" is deceiving at best. Wow is much less easily perceived by the ear than flutter, and 2 tables with the same "wow and flutter" specification can sound quite different, especially if one has mostly flutter, and the other has mostly wow component in that spec.

To sum up, all methods of analog drive systems have their pros and cons, and none is perfect, and implementation may be more important than basic concept.

To focus in on speed stability alone, with no discussion of other meaningful design aspects is incomplete and useless. I've heard very good sounding turntables of varying drive system designs, and also some terrible ones too.

Tunnel vision is not the most productive way to analyze componentry.

Macrojack, I question your conclusion. I think a better read is that both belt and direct drive can work wonderfully, but it really depends on the implementation. One is not really better, each simply has a different set of compromises.

Why is that the wisest answer to so many questions, be it CD/speaklers, cables, tube V SS above all. It is all in the implentation. There are many more belt tables, but some excellent DD ones. being from the UK and a few miles from Loricraft, Garrard springs to mind. It is hard to beat a well renovated and plinthed 301/401 and a 501 would be my ideal, if I could afford it. They seem particularly hard to beat for base response.
A different and more interesting question would be, if you were going to make an ultimate, cost no objest turntable, would it be belt or direct drive? They all really are belt drive, but is that because the extra tooling costs of DD, make it prohibitive when you are going to be selling 10's or 100's, but not 1000's of units. I think that is the reason and it would be possible to match the ultimate belt drive decks, but who knows as there are'nt any to audition.

For people like Raoul, don't forget EMT idler drives.

So...now I have to look into DD or Idle-wheel drive TT?

Here I am ready to upgrade my TT and arm with a VPI, Galibier or Teres and a Schroder or Tri-Planer. Now we have the Garrard 301 Idle-wheel......and Lenco.....OH MY!!!! Now you have force me to read the entire "Home Depot" thread :(!!!

Rick (RWD)

It would be very hard to find an SP-10MKIII for 1200.00 in any decent condition. The last one I saw on eBay went for well over 4000.00.

Raul: I wouldn't know about the sound quality of relatively inexpensive DD's competing beyond their price range (though you might), I was only stating about their speed accuracy and precision. But a caveat has to be acknowledged: published speed distortion specs only deal with combined gross levels, leaving us in the dark about spectral and temporal character. The possibility exists for one TT to have lower measured speed distortion than another, but of a sonically nastier nature.

Dear Zaikesman: +++++ " To me the real-world value of DD might be where it is right now ..." +++++

I agree, we can buy a SP10 MK2 for 400.00 dls ( with out plynth and tonearm ), a Denon DP 800 for 500.00 0r a SP 10 MK3 for 1,200.00. Btw, all these TT designs comes from more than 20 years ago!!!! ). Any one of these TTs ( with the right plynth/footers/tonearm/mat) can compete not with ++++" any belt-driver in its price range. " ++++ ( like you say ) but with the 40K+ Walker BD TT and for a ridiculous price fraction.

+++++ " Which drive method is allegedly "superior" .." +++++

IN my opinion and if we take only the drive system " per se " then the DD is a superior drive system over the BD one. The first and most important function on a TT is the speed accuracy/stability and here the BD system can't compete with the DD system and this is a fact that any one can see it through measurements and own TT specs, period. Btw, ( at least on my TTs ) one musical reproduction characteristic on the DD TT is the more real and natural decay time of the notes, this give to the sound reproduction a better feel of the " live music " against the BD TT.

+++ " .. the evidence could point toward factors other than drive method ruling the roost at that level. " ++++

Yes, there are several other factors than drive system where one or the other could be superior.

About Stereophile: well the champion at the moment is the BD design Continuum for around 90K, speed accuracy? : 0.006%.

Regards and enjoy the music.
Raul.

Raul! What? Out of all those arms, cartridges and table you don't have a good idler wheel? I think you're a great candidate for a Lenco!

Direct drive or die.

Zaikesman,
I feel myself being pulled in your direction. I replaced nearly $10K (used value) worth of separates with a $700 integrated amp that actually sounded better. Boy did that ever feel good. I'm currently looking to see if I can accomplish something like that with my analog. That's how this thread started actually. I did something similar with speakers and cables.
Tom

Raul: Wouldn't the rumble specs, at least, be somewhat dependent on the plinth made for a deck-mount DD?

Anyway, whatever one thinks of Michael Fremer, to me it's interesting that a guy who's critically auditioned that many turntables, and proclaimed the direct-drive Rockport Sirius to be the uncontested best at the time he had it, later decided the belt-drive SME 30 (at about 1/3 the price without arm) equalled or slightly bettered it (with a Graham arm fitted). This is notable not only from the DD vs. BD perspective, but because the Rockport had an integral linear-tracking arm (Fremer has in the past has extolled not only the theoretical but the actual benefits of linear arms if properly executed), air bearings all around, an integral active isolation stand, the more complex motor controller, and was maybe 4-5 times as massive -- none of the which the well-executed but by comparison conceptually basic SME could match on paper. The Rockport may indeed have the better specs -- I don't know that we know, but anyway at a certain point a few more -dB or a slightly lower % may not matter in practical terms -- but for all its engineering heroism, if it doesn't sound clearly superior at its much higher price, which TT is ultimately the better design? And why would a designer then need to go to the trouble and expense of making a direct-drive system in this day and age?

To me the real-world value of DD might be where it is right now on my gear rack: a relatively inexpensive, highly durable, low-maintainance, operationally flexible, speed-accurate, good-sounding TT for not a lot of money, that probably has significantly better specs than any belt-driver in its price range. Which drive method is allegedly "superior" at the top end of the food chain is a debate for others, and hypothetically interesting as the question may be, the evidence could point toward factors other than drive method ruling the roost at that level.

Dear Macrojack: I think that because there are several subjects on it it is almost imposible to tell which one is better: DD or BD.

If we take two of the TT primary functions: speed accuracy and speed stability, we can conclude that the DD beats the BD system: example, the Walker one has 0.002% on this spec against 0.001% on an SP 10 or Exclusive.
If we take the wow and flutter, the Sp 10 beats ( easily ) my Micro Seiki RX 5000: 0.015% against 0.025%.
We can take too the Rumble and here in the case of Walker or Avid it is around 90 db against 92 db on the SP 10 or 95 db of the Exlusive one

Btw, I own SP 10s, Denons, Micro Seiki, Luxman and Acoustic Signature.

From the point of view of how it performs on their designs the DD ones beats the BD: you can " see " at the measurements and this is a fact, period.
It is curious the BD manufacturers almost don't give almost any specs about: I wonder why?.
All those specs are extremely important to know about the quality build design if not which were or which ones are the TT targets on the TT design and how the designer compare the result ( build ) against those targets ?. Of course that the TT designer can had other kind of targets but it does not sense to me if he do not take in count those ones like speed accuracy and speed stability between others.

The TT specs can't tell me " per se " how good is the music reproduction performance but tell me how good care take the designer on the build of that unit and at least on the speed spec can tell me what " to wait " for.

Now, the " best voted " today TT is the Rockport that is a DD design and in the other side the Walker is the best example of what we can have in the BD designs.
Both designs go to an extreme design, here we can't say ( real ) which is better because in both trhey take in count almost all the issues for a perfect TT performance design: speed accuracy/stability, kind of motor, platter resonance/vibrations, energy disipation, plataform, air bearing, tonearm, quality on execution, " beauty on that execution ", etc, etc.

Which one do you like and which one performs better? ? , this is a subjective answer and we can have different answers about like different persons we are.

Which one is better?, here we have to go for facts: measurements, something objective and for this point of view the DD is a better one.

I send to build my plynths of my SP 10 and Denon TTs with a solid beautiful marble and Onyx one piece stones ( 40 kg ), as a fact this plynths function like the tonearm boards. I use the Audio Technica pneumatic suspension footers and tip toes like between TT and the plynths.

These DD TTs are very precise and have better music sound reproduction quality performance at both frequency extremes than my BD TTs: this is very easy to find out, play a piano work in either design. Why am I not using them?: because I need to mount, at least, three tonearms in each TT ( that I can change in any moment ) and the Micro and AS ones comes ready to work on it.
One of my future targets is to build a system plynth/arm board for I can use my DD TTs in the same way that my BD TTs, in the mid time I have to accept a 95-98% ? quality performance of what I can achieve with my DD TTs, not big deal.

Regards and enjoy the music.
Raul.

Mint604,
You bring up an interesting point. All (4 now) drive systems require some kind of maintenance and I suppose it should be a condideration in these comparisons. All the other motors need lubrication and yours requires nutrition. The IW has the most moving parts and would presumably be the highest maintenance system. BD probably only ever needs a new belt although I guess bearings and springs could also wear. With DD the only issue beyond lubrication would be the potential for motor failure and that would be fatal I imagine to a vintage table. Does your rat work quietly?

I use a SUPERIOR belt drive mechanism. under the platter a large 10lb. live rat (rodent) runs on a BELT, the heavy 50lb platter (and three ball govenor) does indeed smooth out any speed irreglarties. There is NO measurable rumble. Completely independant of powerline noise. Feeding and clean-up are manditory.

Then send it to me in email. I'm very curious to hear what you have to say on the subject.

Dan, I wrote this dreadfully huge post disagreeing with your presumption that static inaccuracy in baseline speed is more of a factor than dynamic micro-speed variations. I don't want to post it the way it is, so I'm just saying so, and we'll see if I ever elaborate ;^)

Macrojack, you are one fine gentleman.

4ynx: Do you not understand the difference between "this table/arm/cartridge sounds better to me" and "since this table/arm/cartridge sounds better to me, it's drive system must be better"?

Drubin,
I have a friend who insists that perception is reality. There's something about the comment that disturbs me but there's nothing there for me to contradict. That said, I certainly wouldn't think to kick you out of the club. In fact, your candor is grounds for promotion. I would guess from your writings that you would be more comfortable with 4yanx in the hearing dept. than with seandtaylor in statistics.
Personally I wouldn't consider a thread successful until it attracted your comments.

I'm in violent agreement with you about measurements, David. However, when what I hear flies in the face of reason (irregardless of measurements), I want to know why, or at least I want to think it through. That's just me, and it reflects my self-doubting personality.

I'll make a confession that may get me kicked out of the club. I used to believe fiercely in "trust your ears," but I have come to suspect that our ears (mine at least) can sometimes lie to us also. This does not mean that I choose what measures best (I don't pay attention to that), only that I pause and reflect if something doesn't make sense. I may end up choosing components or techniques that don't make sense but sound best to me (e.g., using a linestage). The thing is, I don't do so without first questioning it, and I continue to question it even afterwards.

Of course THAT could be accomplished. But that tells you absolutely nothing about whether belt or DD is superior. It only tells you whether one combination sounds better than another. If that's all you want to know (and for most audiophiles most of the time, it probably is) that's fine. Just don't draw unwarranted conclusions from any such comparison.

So what would you rather have, something that sounds best to you or something that the numbers say is "superior" to something else? The definition of "superior", at least im my music room, is what sounds best, not what some imperical set of measurements say. A bucng of the 70's amps were so good by the numbers that they should have been creating live music - unfortuantely, many of those same amps sounded like crap. I would draw a conclusion that something was better based on the sound it made everytime and look at a decision based on measurements as the unwarranted choice. But, that's just me, maybe.

Drubin, I don't think accepting what one hears as true mean abdicating reason and critical thinking. Just saying that measurements can lie. When they do, THAT is whan you NEED reason to tell you the REAL truth! ;)