Is Direct Drive Really Better?

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.

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.

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.

Chris,

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

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

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.

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.

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.

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.

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.

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.

"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 ?

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.

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.

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,

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.

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 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?

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 :-)

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.

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%

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.

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?

No. Think about it again :-)

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.

Johnmathias,

My first TT was an idler wheel drive.

So much for trying to be a *psychic*.

***

Zaikesman,
I think I understand your point. Recreation of the original performance requires retracing the original steps at the original pace. Or in other words the duplicate must be exactly symmetrical to the original in order to precisely mimic it in reverse -- mistakes included.
The concept is simple enough but saying it so that others can understand my meaning isn't quite so simple.

No. Think about it again :-)

Right you are, sir.

Macrojack, I built an idler wheel table from a Lenco and I would not consider myself to be a DIY guy (although I am getting better) - it's not that hard if you have the time to do it. You cut some plywood and MDF to the same size, cut out the cavities for the guts of the lenco to fit inside it, glue the layers together, bolt the lenco onto the plinth, finish with self-adhering veneer or stain it. The veneer covers a lot of the mistakes. If you use the right arm or turn the thing 90 degrees, you don't need to cut the base plate to set the arm. You clean the motor and the bearing, stick some dampening under the plate, and for $500 you're stunned.

I don't have an opinion about which is better in the drives, but I will say without any reservation that I have enjoyed the hell out of mine. If like me you really get turned on by value, well, this is a real value in audio.

Plus you get to tell people "I built a turntable" and that in and of itself is worth the effort.

Lenco's are on ebay all the time - there are some specific models to buy and some to avoid. I used an L 75. I think the 69 (someone correct me if I am wrong) is also good - these have aluminum idler wheels rather than plastic.

So, if you really are curious, I am your role model. If I can do it, you can do it.

MJ and V: Obviously we can't achieve a correct 1:1 correspondence, or probably even seek one realistically speaking. (Although if that were the goal, then you could make the argument that going with a Technics SP which used the same motor/controller as a Matsushita disk-cutter would be a reasonable strategy. However, lacquers aren't the same as vinyl, cutter-heads aren't the same as cartridges, and of course inscribing a groove isn't the same as following one.) The real point may be that, even were we able to achieve "perfect" playback with zero speed distortion (which we can't), if the record weren't cut the same way, you'd still wind up with speed distortion. Boiled down: You'll always have speed distortion. But we already knew that.

As to Viridian's observation, if our theoretical turntable suffers less dynamic drag on transients than the cutting lathe (maybe not as unreasonable an assumption as it might seem, given the presumably much greater frictional resistance encountered by a cutting-head in inscribing the groove as opposed to a stylus merely reading it), then pitches will go slightly sharp on transients. If the turntable suffers more dynamic drag than the lathe on the other hand, then transient pitches will go slightly flat. All in all though, I don't think it's completely unreasonable to speculate that these speed distortions at the mastering and playback ends might indeed have some rough natural correspondence which tends to mitigate the problem more than exacerbate it.

Expounding a bit: Viridian, your last question I think may really concern phase. You might be thinking of "flanging" as an analogy, or the way loudspeakers behave regarding crossovers and multiple drivers or reflective room surfaces. If so, that would not apply to this situation, it seems to me -- that sort of reinforcement/cancellation phenomana requires mixing of more than one sound source, which I think the encode/decode of vinyl playback doesn't qualify as. You are right that pitches are affected, and the resulting pitch distortions will derive from addition and subtraction, but I don't believe there is any constructive/destructive reinforcement going on as I understand the concept. For instance, to "flange" as they originally did in the recording studio, you need two reels of tape both with the same signal recorded on them, played back in synchrony, which is then modified by applying friction via the engineer's hands to the reels' flanges. But if you recorded one reel of tape while altering the pitch by applying drag to the flange, and then played that pitch-altered reel back while doing the same thing again, the "flanging" effect would not be the result, just further pitch distortion.

This is good!

Dear Zaikesman: +++++ " 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. " +++++

No, definitive I don't agree with you: ovbiously speed stability is a critical and very important TT subject but first than all we need speed accuracy, that's mean that first we need that the TT drive system runs exactly at 45 rpm ( example ) not at 44 or 46 rpm. It does not matters that a drive system has good speed stability if not has speed accuracy. In my opinion first we need speed accuracy and the second most desired characteristic is speed stability.
I don't agree too with : ++++ " Accuracy isn't that hard to achieve " +++++. I think that you are only " talking " ( with all respect: brain-masturbation . ) with out any scientific info that can confirm your statement. If it was not hard to achieve then we should have several TT with a speed accuracy of 0.001% and we only have two of them. Where do you learn or which are the facts that confirm your statements?

Here it is another of your BM that have no value at all because this BM can't be corroborated for any one ( you are accelerate your " car " in " neutral " . ):

+++++ " 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. " +++++

I'm not saying that you can't have all those BM that you posted and many more, what I try to explain is that those BM don't permit to any one to go any where.

I suggest that because you are very interested on this thread make a extensive research about your statements and share with us the facts that you find it.

Dear Zaikesman, you statements in their today status confused to many people and what all we need here is to have a clear and precise information on the thread subject with out speculations that can be corroborated.

Regards and enjoy the music.
Raul.

In my opinion first we need speed accuracy and the second most desired characteristic is speed stability.

My ears need both, equally.


Raul,
Please do extensive research on "brain masturbation" before posting about that topic again. We need clear and precise information on the subject, not speculations that cannot be corroborated. Lab-tested specifications from the manufacturer would be best. You probably have access to them!

Direct drive is better if your a DJ/rapper. Direct drive transmits more vibration to the platter where as in a belt driven turntable this vibration is isolated by the rubber belt itself.

Now THAT's not good. Rewind.

Phd- That's a very old story and it is not supported by rumble figures as far as I know. I've read that the resonant frequency of the drive motor and bearing in a good DD is like 5 Hz or something. It's supposed to be too low for the cartridge to pick up. I also remember a tale about ID tables developing a flat spot in the rubber idler wheel if left idle and engaged for too long. I think that last one was started by the tooth fairy.

Really. Consider yourself busted, Phd.

Ok I'll rewind. A few years ago I owned a direct drive turntable, couldn't get much volume due to rumble, I thought the speakers were going to come unglued. Switched to a belt drive turntable & life was much better. Maybe more current direct drive designs have improved.

Phd- Isolation has improved as we have become more aware of it. Your direct drive experience might have been due to feedback. Or it could have been an inexpensive direct drive. Several posters have noted that cheapo DD tables tarnished the rep of the genre back in the day.

Another thing, one only has to look at the specs between a belt drive & direct drive to see a clear improvement in wow & flutter specs. I would think that when the platter is part of the motor which is the case in direct drive, this would be the kiss of death.

My SP-10MKIII is as quiet or quieter than anything I've heard and I've heard a lot. Phd have you read this thread from the beginning?

Raul: "BM" for "brain-masturbation"? (Well, I guess those who've got... BTW, "BM" is already taken my man, or didn't you know? Or maybe you meant it that way? Classy!)

Look, it's regrettable you can't handle being disagreed with in good grace, but I stand by my comments. Speed-stability is the crucial issue, not speed-accuracy within reasonable limits. IMO.

Of course it's better to be more accurate, and 0.001% is speed-accurate. So is 0.01%. So is 0.1% -- that equals a mere 1Hz error for a 1,000Hz tone, which if constant has zero perceptible impact on the listening experience. Even a 1% static error alters the essential character of the music only very slightly, and even then usually only in direct comparison with the correct speed. 0.001% vs. 0.002% baseline inaccuracy means nothing, you cannot hear the difference. And it's not even worth getting into how valid or comparable the claimed specs you're throwing around here are anyway -- probably half of those quoted mean nothing as well. Judging from your posts, you seem to think that listing specs somehow qualifies as "scientific" as you say, or is a substitute for making a cogent argument. Guess we could call that "SM" if it hadn't already been taken. "With all respect", Ciao.

Anybody seen the new Grand Prix Audio Monaco DD described in April's "Analog Corner" CES report? Quothe Fremer: "Ultra-compact...magnesium platter...bronze flywheel...CPU-controlled...5,000-point optical reader...platter which is also the rotor (sound familiar?)...only mechanical attactment point is the bearing, no contact in the horizontal plane...composite polymer-damped plinth...aluminum billet armboard...$15-20K? Albert? You getting one of these for review to go with those racks? Now there would be a DD vs. BD showdown for you.

Rwwear, I have not read that thread. Can you tell me what a SP-10MKIII is?

Even a 1% static error alters the essential character of the music only very slightly, and even then usually only in direct comparison with the correct speed.

Alex,

That's the first statement you've made that I'll specifically disagree with. Given sufficiently transparent yet harmonically complex music, a 1% static speed deviation is quite audible. The music's harmonic structure will be damaged.

I'm not referring to anything esoteric. Mozart's orchestral scores are a good test. Nothing seems simpler, but his harmonic relationships are far more tightly inter-related that is usually appreciated. Change playback speed by 1% and they fall to pieces.

To be fair, this does require a very transparent sytem to be audible. Bloat or overhang from any component will readily mask the harmonic damage from a 1% static speed error. My old c-j and Bent components did. So do Aesthetix and Supratek, for that matter. Dan_Ed, Jyprez and Swampwalker could attest that our Nick Doshi stuff has the requisite transparency. When they visited recently I didn't specifically demonstrate the audibility of a 1% TT speed error. But I could have.

Phd, the SP10MKII is an upgrade from the Technics SP10MKII that has a 28lb bronze and aluminum platter and an outboard power supply with speed control.

"Speed-stability is the crucial issue, not speed-accuracy within reasonable limits."

Zaikes ... I agree with you. If speed accuracy were more important the CD vs LP debate would have died long ago.
Speed stability is what really counts.

Regarding the limit of discrimination this reference has it at 0.5%
http://www.indiana.edu/~emusic/acoustics/pitch.htm

So you could argue that the difference between 0.001% and 0.01% is academic. I would even argue that the orchestral players are not able to tune their instruments to better than 0.1% so you are fooling yourself if you think a turntable needs to be substantially more accurate.

Since speed stability problems cause direct distortion to the waveform they are much more noticeable.

Doug ... how does an absolute speed error break harmonic relationships ? If we are 1% fast then a lower A is 444 Hz (instead of 440Hz) and an upper A is 888Hz instead of 880Hz. The doubling of frequency per octet relationship is still maintained, just shifted slightly 1% up in frequency.