Like Raul said, please tell us who regards pitch control and (or) direct drive as sacrilege? Of course, the two are not necessarily synonymous, but we can leave that aside for now. Another attack on useful discourse by the pointless thread starter.
Alex, SP 10 mk3 definitely does have a pitch control; it’s built into the outboard power supply.
Fremer’s “hunting” hypothesis is the favorite criticism of DD by those who prefer belt drive, but it is very unfair to apply what is or may be a problem with the SL1200, a low end example of the breed, to all DDs. Otherwise we could bring up the inherent speed irregularities of BD due to belt creep and stylus drag.
Different servo control designs had different correction rates. Apparently the one built into the SL1200 makes very frequent corrections that might be audible to some. Moreover it had a cheap iron core motor.
It’s just my opinion but I would not necessarily agree with your sorting of DDs into 4 categories. And you left out many superb products, but I’m sure you know that. No biggie.
Alex, Funnily enough, I went from SOTA Star Sapphire III to Nottingham Analog Hyperspace (a big improvement) to modified Lenco (a big improvement over the Notts) to my current stable that still includes the Lenco plus four vintage DD turntables: DP80, L07D, SP10 Mk3, and Victor TT101.
Harold, I don't know what was wrong with your PD444, but it ought not to have sounded "digital". Did you have it serviced and calibrated at any point? Proper calibration is absolutely key to getting the best out of any DD turntable, old or new. But if you're living happily, that's all that counts. As for me, I could not go back to (as affordable) BD at this point, even though I have listened to a few really good ones that cost more than $25K, too rich for my blood.
Chakster, If you see Harold's follow up post, it seems that he really found no substantive fault with his PD444, except that you could say it was too perfect, and he prefers his belt-drive. Personal taste has a lot to do with this.
Harold, From what you say, perhaps your PD444 needed no servicing, but it's impossible to know for sure except to say it wasn't grossly malfunctioning. As to servicing, the schematics for most of these vintage DD's are available on-line, and for a knowledgeable tech with the proper equipment, which is pretty basic stuff for a pro, calibrating a DD is no big deal. For sure, you would not have had to send it back to Japan. For example, I have the schematics for the L07D, the SP10 Mk3, the DP80, and the TT101, available from Vinyl Engine or Soundfountain (the SP10 website) or other on-line sources.
With respect to the general question posed by this thread, I would point out that the modern trend in the most advanced belt-drive designs is to have an outboard motor controller. A subset of those devices incorporate a feedback mechanism that transmits platter speed errors back to the controller which then sends a message to the motor to correct the error. In addition, we have the recent outboard devices, like the Phoenix Engineering pieces, that set up a feedback mechanism for platter speed control and can be added to even older belt-driven or idler-drive turntables to improve speed stability. So, it hardly seems logical to disparage direct-drive turntables for incorporating a quartz-locked feedback mechanism that makes speed corrections. (Does Fremer realize this?) If servo systems are so bad, why is the trend toward adopting similar mechanisms? True, it can be done well or done badly in any case. If done badly, I imagine it could introduce an audible kind of distortion, but I also think the problem is over-rated by those who prefer other drive systems.
On the DP80, if you select the option to adjust speed, you give up the quartz-locked loop circuit, and the speed constancy could be less good. I don't know how speed adjustments are achieved on the TT101 or on the SP10 Mk3. The TT101 may have a series of discrete quartz-locked circuits, selected on the front panel, one for each selectable pitch.
Alex, Sorry to contradict you, but most vintage Japanese DD turntables used light-ish platters. The most notable exception is the SP10 Mk3, which has a 21-lb platter. The Pioneer Exclusive P3 also had a fairly heavy platter, but not as heavy as that of the Mk3. On the Yamaha GT2000, there was the "GT2000X" version, which could have a gunmetal platter, probably pretty heavy, probably made by Micro-Seiki. That version also came with a heavy duty spindle and upgraded motor. The GT2000X goes for about twice the cost of a GT2000 these days, if you can find one. I guess the L07D platter is also in the category of "heavy", at about 15 lbs, with an optional peripheral ring that adds mass and inertia. I don't know where the PD444 fits in; I've never seen one in the flesh. Perhaps Chakster can comment. Other than these 4 and possibly the PD444, you would find that the platters tend to be less than 10 lbs.
The iron core motors used by many could be DC or AC synchronous types. The DP80 which has a very light platter has an iron core motor that is 3-phase AC synchronous, which affords a lot of speed stability without much servo action. But my favorite tables have coreless motors. For example, the TT101 has a lightweight platter and a coreless motor. The L07D uses a coreless motor to drive its heavier platter. I could be imagining things, but it seems to me that the tables with coreless motors are most "musical" sounding, possibly due to less or no cogging effect. I can't prove that, and I would not argue too much about it one way or the other. So I would summarize by stating that many but not all of the vintage Japanese decks are indeed like the EMT 950.
Melm, so, where is it that I don’t know what I’m talking about? I own an eagle and road runner. Together they run my Lenco very well and accurately. The servo device in the Kenwood L07D also has a loose operating point in that it only makes corrections when speed has slipped a certain amount and that’s part of the reason for the large heavy platter, So that rotational inertia as well as the servo feedback serve to maintain a constant speed.. My point was that since modern turntables of all types are more and more adopting speed correction devices, it hardly behooves one to criticize vintage direct drive turntables for employing a servo feedback mechanism. I said more than once in my previous posts that some of them work better than others. So what do you want from me? Maybe it’s best not to preface one’s remarks with an insult.
Also, I am not certain of this, but I might take issue with your description of the function of the eagle and Road Runner. The manual says that there is a blinking light in the road runner read out that indicates when a correction is being made. During run up one sees that light blinking with at least every revolution. Once approximate correct speed has been attained, the light blinks much less frequently but still irregularly.This indicates that there is more going on with the eagle and roadRunner than simply making a correction every three rotations of the platter.
13blm, just to continue this conversation, I would point out that the bearing of a belt drive turntable is under a unique stress that does not pertain to direct drive and most idler drive turntables, in that there is a sideways force pulling on the spindle shaft. In theory this could cause uneven wear, and eventually result in a minute amount of wobble. Not to mention that this force in the horizontal plane can also add noise. I am bringing this up for fun debate purposes only, not to get your goat.
My Notts turntable sounded way way better after I inserted a Walker Audio Precision Motor Controller into the AC supply and calibrated the speed. However, everything associated with speed stability (e.g., pitch stability most easily detected with piano music) got even better when I replaced the Notts with a Lenco L75. And the Lenco got better with the addition of the Phoenix Engineering stuff, including the RR. Once the Lenco is up to speed, the RR feedback is doing very little; you can see that by the frequency with which the unit tells you it is making corrections. The frequency of flashing goes way down to once every several revolutions, whereby the unit is making corrections on the order of less than .01 rpm, up or down. So I don't see how the RR corrections could be causing any audible treble problems, but you hear what you hear.
Uber, This is all nothing but my opinion based on owning two consecutive Lenco L75s, one that I bought from John Nantais with one of his heavy plinths and his other tweaks, and the other that I bought absolutely stock (NOS) and tweaked myself. First, I never listened to my NOS L75 before modifying it, but most experienced Lenco persons say the OEM unit can sound very good, with the Achilles heel being the tonearm. Yet, there are those who defend the tonearm as at least being OK. I really liked the Nantais Lenco, but I was bent on building one with a slate plinth, so I sold my Nantais version and had created a slate plinth for my OEM Lenco, using a 65-lb slab of Pennsylvania slate and the pattern provided by Peter Reinders (do a search on that name); it was cut with a waterjet using Peter's pdf file to program the machine. I then also purchased a massive aftermarket bearing made by "Jeremy" in England. I had the platter painted with a thick coat of vibration-absorbing paint, and I further dampened it using large O-rings stretched around the circumference, below the playing surface. Last, I regulate platter speed using the aforementioned Phoenix Eagle PS and Roadrunner tach. You don't have to do all or any of these things to get a nice sounding turntable for the cost of an L75 alone. I paid $500 for my NOS one, but good used ones are typically around $300, or at least they were, back then. I would say that my slate Lenco stacks up along with all my DD turntables except the SP10 Mk3 and the L07D, but the differences are not night and day. The latter two DDs are just a bit more completely neutral. You should go to the website "Lenco Heaven" for more information.
13blm, In my opinion, there are two basic schools of turntable design: heavy platter/weak motor vs relatively lightweight platter/strong motor, typically with speed regulation. As you and others have said, the heavy platter itself provides a form of speed stability due to its rotational inertia. Also "weak motor" always means belt drive, because the motor of a DD would have to be very powerful in order to motivate a heavy platter, e.g., the Technics SP10 Mk3 with its 21-lb platter and massive hi-torque motor. Avid turntables are examples of belt drives with relatively light platters and strong motors. Most other high end belt drives are massive platter/weak motor types. (If you want rotational inertia to keep constant speed, you don't want a powerful motor that can disturb the equilibrium.) Also, with a belt drive, you get the mechanical advantage of the small pulley driving a much larger wheel (the platter), and therefore a weak motor can work. I don't like blanket statements, like a heavy platter is always better. It depends upon how you want the speed to be maintained.
Uber, the website “Lenco Heaven” will tell you everything you could want to know about the L75, and more. There are a few inexpensive vintage tonearms that are drop-in replacements for the original. And then you’ve got something really good. You can also read about the crazy things that others have done, with the L75 as a basis. Apologies to everyone else for stealing this thread for a moment. I will cease to spout off on Lenco.
What matters is to listen to a wide variety of turntables of all types, carefully and for extended periods of time in one's own home on one's own carefully selected system, and thereby to decide what sounds best to one's own ears. That process in reality never ends. If you have honestly taken on that task, then there are no explanations necessary. And this thread is a waste of time, although it is a credit to Vinnie, who definitely knows how to start an argument and now must be laughing his ass off.
For every pro and con in favor of one drive method, there is a complementary pro and con for either of the others. The matter cannot and should not be expected to reach absolute conclusions and certainly not through verbal debate. If you think you own the one and only absolute truth, you've missed the point.