Martinhall wrote, "A `feature' yet unmentioned(unless I missed it?) A DD TT unit that provides good enough torque to sustain resistance to stylus drag, unfortunately exhibits magnetic noise induced into the cartridge as it tracks the inner part of a record."
If Martin is still alive and still cares, let me say that the fact that he observed this phenomenon with one DD turntable (Micro Seiki) and presumably one unnamed cartridge does not mean that this is a general issue with all DD turntables. And if it were an issue with a particular combo of tt and cartridge, it is a relatively simple matter to devise a shield that prevents motor EMI from affecting the cartridge. Also, the M-S DD turntables (DDX and DQX) are not highly regarded in relation to the large number of high quality belt drive tt's made by M-S or indeed in relation to other vintage Japanese DD turntables, so it is a bit unfair and misleading to form an opinion of all DD turntables based on the M-S ones. |
Very interesting thread. Perhaps the best analogy with regards to using a high torque motor with a relatively light platter was espoused by the EMT manufacturers - namely that it's like driving up a hill on a windy road - if you have a heavy truck it would go up still using torque etc, but a light sports car will be better able to cope with those speed shifts than the truck.
I currently use a belt drive, but have an EMT 950 restoration brewing, and have a lenco to collect. I am fascinated at the forthcoming shootout that I will carry out at the end of the year.
Personally there appears to be elements of 'emporers new clothes' on this thread. I've done some DIY in my time and my ethusiasm for my diy often blights my listening skills - ie I often think that what I have cobbled together in my workshop is better than the combined might/research/manpower of the R&D team at Proac/Yamaha/Quad combined.
Whilst I think that Mr Salvatore has some strong opinions, it does not mean they are always right - if that at all. His perception that Zyx are the best cartridges in the business is dubious IMHO, likewise the Shelter 501 is nothing like a transfiguration temper. I have read his Lenco reference review, and I will carry out some listening tests of my own.
I will say something that was quite interesting though. I once spoke to Martin Colloms, and he said that people are sensitive to different things - having heard what I have in my sytem, he said that I am probably particularly sensitive to timing. Some people retain their high frequency sensitivity for far longer than other people.
Balancing this against what Ken Kessler once said at a show - he's listened to hi-fi for 30 years, yet no system can ever reproduce kettle drums hit by a muscular man - they either get the speed of the impact and strike, or they get the weight, but never in the full and equal measure of the real thing.
Applying some biological detrioration - peoples hearing deteriorates over the years - especially 30 years.
What does this rambling mean? Well it's a bit like the angels dancing on the head of a pin - we will all ultimately look for different things in our systems. I am certain that there will be pros and cons of each design ultimately. |
In my last post I had the Shindo Labs turntable, arm, and cartridge. This, of course, was the remodeled Garrard 301 and a rim drive. I now have a Bergman SIndre turntable and arm with the Ortofon A-90 cartridge. It is a belt drive. They sound different.
I must say that I have had enough experience with isolation devices, most recently with the StillPoints Ultra Stainless Steel feet, to realize we are mainly just moving around the vibrations that are coloring our music reproduction. With the StillPoints, I finally know what real isolation means. I have them under my Bergman.
I once heard a good experiment with the same turntable with identical platters except that one was mpingo or ebony and the other acrylic. When the acrylic was put on, everyone said go back to the wood. I would love to hear a similar comparison or other materials for the platter and of rim versus belt and direct drives. Until that time, I love my Bergman. |
A `feature' yet unmentioned(unless I missed it?) A DD TT unit that provides good enough torque to sustain resistance to stylus drag, unfortunately exhibits magnetic noise induced into the cartridge as it tracks the inner part of a record. I came against this on Micro Seiki TT's in the early seventies while working at Howland West Audio (Eden Grove Holloway, remember it?) and even after several visits from Micro's design engineers it was not completely cured, unless you reverted to using a Decca Deram ceramic crystal pickup!!! This was otherwise a very fine turntable and if you only listened to highly modulated recordings, wasn't a problem, very quiet classical recordings however......! So, I never bought one, However in '74 I bought a GL75 which I still use and enjoy. Yes the arm is a pig to set up*, yes the `v' blocks wear out, but that takes forty years, yes it IS a jocky wheel drive (completely out of fasion when I purchased it) so what? There is NO rumble (not even today on the original wheel!)Heavy percusive bass (remember early Reggae?) doesn't faze it and there isn't the faintest wobble in a drawn out violine note. The decoupled counter weight on a decoupled arm (rubber `V' blocks) really does give the music a chance to be heard.
* For those that want to try to set up a L75 arm, I've found that for best results the deck must be level, the arms height shoud be so that with the stylus on a record, the arm tube should be horizontal to the deck, there should be equal `clearance' bellow and each side of the arm tube and its shroud (undamaged `V' blocks). |
Dear Teres: It is a fact that in your subjective TT evaluations you really like the wood " colorations " against metal ones, that´s fine.
My question about TT material was because you are in a new TT design and I only try to tell you: look for other material options.
Btw, some of the big names in TT, both DD and BD, are all metal designs: Rockport, Walker, Verdier, Acoustic Signature, Simon Yorke, Micro Seiki, Denon, Technics, American Sound, Final, etc, etc.
Regards and enjoy the music.
Raul. |
Teres: Although my TT is made entirely of cast aluminum, I can relate to what you say, since I have guitars with bridges made of all these options: rosewood or ebony; brass; or cast aluminum; and in this application the first two definitely work better than the latter, which thins out tonality and reduces sustain. My only question would be, is what we're looking for in a guitar bridge necessarily the same thing we want in a turntable base (or platter)? Your listening tests would seem to answer that, although the number of well-regarded TT's using acrylic or aluminum would seem to reach a different conclusion (can you imagine a guitar bridge made of acrylic?). And it intrigues me that Nottingham uses cast iron and VPI uses stainless steel, both of which unlike brass seem vibrationally more inert. Then of course there's Rega's ceramic platter... |
+++ do you think that in this moment your non-metal DD design is a better one? or do you make it in that way because looks better than an all metal one? +++
Good question Raul. The short answer is that we use hardwoods primarily because of the sound, looks are secondary.
The first turntable to come out of the Teres project was my design that used a well damped all aluminum base (http://www.teresaudio.com/fame/1.html). The very first base that Teres offered was 3" thick acrylic. It looked good and was both inexpensive and simple. The sound was OK but was not nearly as good as aluminum version. On a hunch we decided to try making a base out of rosewood loaded with lead shot. To our great surprise the sonic result not only exceeded the acrylic base but also far exceeded my all aluminum base.
I have experimented with many materials and have yet to find anything that delivers subtle midrange detail and texture like dense hardwoods. Carbon fiber comes close but lacks some of the warmth. I find that aluminum is detailed and pristine sounding. However, compared to hardwoods it sounds whitewashed in the midrange and there is a lack of "life". I think that there are a couple reasons for this. The first is rigidity. Most people are surprised to learn that hardwoods like cocobolo are much more rigid than aluminum. A 1/8 inch thick ½ inch wide strip of cocobolo cannot be bent with bare hands. However strip of aluminum of the same size is easily folded in half. Also hardwoods have a chaotic grain structure that varies greatly in density. This varied density is good at both dissipating and breaking up resonance.
I have also experimented with other metals and prefer both mild steel and stainless steel to aluminum. The steels offer a more clarity and detail but also sound a bit too harsh and analytical. Of the metals I find that brass is far superior to steel or aluminum. It is detailed and rich without ever sounding harsh like steel or smeared like aluminum. We found that replacing all of the aluminum parts on the Teres 340 with brass was a major upgrade. Brass is very expensive so it is not often found in turntables. However, I believe it's properties easily justify the cost. The new direct drive Teres will continue to use hardwoods but more brass will be used. |
Tbg: Which post was I repsonding to? The last sentence of the last post prior to mine. (Read before I respond is always my motto!) I don't have perfect pitch; like most people I'm sensitive to relative pitch, but elasticity of pitch is one of the qualities which can give music a lot of its emotional power. Either way, speakers that rotate phase don't affect pitch, but yeah, it so happens my speakers don't rotate phase.
Dan: Was that you? Each time? Hey, I wouldn't have told anybody... |
Was that you, Alex? I felt so stupid, and it wasn't even the first time. |
Zaikesman, what post does this respond to? I kind of agree with both of you. I sit in performance cringing to singers or violins being off key while most sit unmoved by this, including my wife. Having perfect pitch is a two edged sword. I imagine that three way speakers with an out of phase midrange bothers you also.
I now use a highly modified rim drive and it causes me few problems when listening. |
"I still stand by my remark that most audiophiles cannot hear pitch problems even when it hits them in their face" Then I guess it wouldn't shock you how many times there've been when I've gone to a seller's house to audition something or other for sale, and wind up informing the poor guy about which driver(s) ain't making any sound in which channel ;^) |
I feel the need to correct here something I have said in my post above concerning the Lenco speed stability, and at the same time give some useful information to Lenco modifiers. In my post I complained about the wow and flutter of the Lenco turntable but I have lately learned the problem was elsewhere. When I modified my Lenco I built for it a very massive plinth (about 30 kg) and mounted the tonearm on this plinth. What I heard was very noticeable wow and flutter. I tried every remedy possible, cleaned and oiled the turntable everywhere, tried to install heavier tonearms (SME 3012), different cartridges, different Lenco motors, spindle, new idler wheel, nothing helped. Then out of despair, before dumping the thing on the street, I decided to mount the tonearm in the original hole of the turntable: this is supposed to have two drawbacks: wrong distance from arm center to spindle and incorrect vertical angle. However, the wow and flutter problem has simply disappeared and the turntable now sings! I know this might sound puzzling but it indeed shows, I believe, that tonearm mounting is very important to overall turntable accuracy. As for the sound, this modified Lenco does have a very full and neutral sound (I use now a moded Rega rb-250 with a Grace cartridge) and I certainly can live with it for many years. By the way, to check for the wow and flutter problem, I suggest using a piano piece like a Chopin waltz. If you have a wow and flutter problem you will hear the pianos sound sour-like. For people who listen mainly to Jazz this might not be much of a problem, but I can assure you that once the problem is gone, your setup will sound completely different. So my apologies for the Lenco aficionados out there, although I still stand by my remark that most audiophiles cannot hear pitch problems even when it hits them in their face. Cheers. |
Dear Teres: First congratulations for be on that DD design and for trying to give to the analog audio community a diferent option about, not an easy task where almost all the audio community thinks that the BD design is the best way to go.
I know that your DD design is almost at the final stage and I know that because I don't have the opportunity to hear it I don't have the " feeling " of the quality sound reproduction, but I know very well other DD TT performance and I can imagine ( a little ) your DD TT design performance.
I always support the all metal TT designs against the non/full-metal designs and I already posted that the all metal Galibier or AS or other metal ones beats the Teres wood/acrylics ones. For what I read through this thread your DD design is npot an all metal one: is there any reserve about that preclude your DD design to be an all metal one? do you think that in this moment your non-metal DD design is a better one? or do you make it in that way because looks better than an all metal one?
Regards and enjoy the music.
Raul. |
Interesting stuff, I hope Teres comments on it. My own question at this point would be, what proportional contribution can we ascribe to the control system implemented on the DD, beyond the mere fact of the drive method itself? My own hunch is that this is where the greatest theoretical advantage of DD may lie, in affording the possibility of precision-designed platter control... BTW, in response to two points raised above: I suspect resonance is probably still somewhat more sonically determinative than speed distortions in modern high end designs; and when Twl writes: "I think it is because turntable designers all have varying degrees of understanding of the entire turntable system, and place varying amounts of emphasis on "perfecting" the various aspects, within a certain price range, and possibly with different technologies and approaches.
It is definitely not a foregone conclusion that just because a company makes turntables, that they are "expert" in the field. And even "experts" have holes in their knowledge base. And even if they do know everything(impossible), they cannot implement perfection, or even close to it at any affordable price range.
So, what you buy is inherently a compromise.
What types of compromising, and how well the compromises work as a whole, will determine the results" that about says it all, and if anything may be understating the case. With the proliferation of TT's these days, and especially moderate-to-mid-cost ones, my guess is that plenty are not really comprehensively "designed" at all, just aesthetically pleasing combinations of common elements, made and marketed to price points with full knowledge that they will never be technically scrutinized by the audio media, only subjectively compared to similar offerings. |
Dan, I don't want to steer this thread toward Zu so I'll email you privately about that.
That comparison is intriguing to consider given that in the day of the SP-10 there really wasn't an arm or cartridge like Chris used and isolation and cabling hadn't really even gotten started. Just how close can you get to a 380 using an older DD and modern ancillaries? I bet the performance difference is a fraction of the price difference. |
Good one, Tom! :) A good question as well. I suspect that the SP-10 would have better tempo but perhaps not quite the dynamics. That's just my humiliated guess. (Really wish I hadn't missed the Druids!) |
My son, who was with me at the Teres show, said the 380 had more pluck. I guess that more or less sums what Dan_Ed was saying about the difference.
Dan, where you wrote IMHO above, Does that mean "in my humiliated opinion"?
I find myself wondering where something like a Technics SP-10 would fit into that hierarchy. It has the torque but not the platter mass of 380. Would it outperform a 320? If not, why not? |
That's the 2 mil mylar belt, which is a close second best of all the ones I've tried.
Dan may remember seeing a holographic silver belt on our table. It out-torques the 2 mil clear one by a small but audible margin, not because of the color (presumably) but because it's about 10% thicker. This seems to be the optimum material for this application. When I went up to 3 mil mylar the sound started going fat and soft again. That belt was too stiff to make the sharp turn around the motor capstan without slipping.
At any rate, that clear belt is quite good. This makes your report on the superiority of the DD table even more convincing.
|
I also remember him using a clear belt. |
I'm pretty sure it was a clear belt that was used on both the 280 and 320. |
Dan,
Do you remember the color of the belt on the 320 and 280? That isn't as silly a question as it sounds.
While I don't believe a BD Teres will ever match a well implemented DD Teres (especially when the DD costs twice the price) it is true that torque delivery on a 320 is significantly affected by the choice of belts. I've probably tried more belts on a 320 than even CB has had time to play with. I'm curious which one he was using.
Doug
P.S. Two or three years ago I posted a thread describing belt experiments on our original Teres 265. I commented that the increased torque coupling from 1/2 mylar vs. silk thread had no real downside because the Teres motor was so quiet that motor vibration was a non-issue.
Eldartford made a wise observation: if the motor's so quiet why not make a direct drive? It looks like we're just about there, and that he was right.
|
Thanks. I knew it was a tough question. |
Drubin, I was expecting this question and I have thought about it some. My take that on it is rather than just being belt or direct drive that makes the difference it is more the proper application of torque. But to more directly answer your question I would assume that this is true. I wouldn't stretch this out and say that all DD's are going to be superior to belt drives in tempo and speed stability and the same would apply to idler wheels, IMHO. |
Dan, do you have any sense of whether the differences you heard in the 380 match up with the kinds of differences people seem to hear between BD and DD generally? Put another way, was it the "DD sound" that you heard (admittedly at a very high level and admittedly with a whole lot more going on)? |
No offense at all, 4yanx. I understood what you meant and what the point of your question was. Macrojack is correct that the word humiliated can have a malicious connotation, but it also means humbled, which is the meaning I had in mind. I do accept that it may have sounded a bit sensational of me to use that word so that's why I suggested humbled. Enough with the semantics. :)
I went in expecting to hear a difference very much along the same lines as what 4yanx's describes. That is, I expected to hear a small difference but more on the lines of a cartridge swap. But the difference was much more profound. Perhaps this is because we don't often hear this level of change in the tempo of music reproduction. There is also, I believe, much more brass used in the platter so it is not the same as just taking a 320 and installing a direct drive motor. Again, this could help explain the obvious increase in dynamics along with the Reference arm and Universe. I was having too much fun just listening to enguage Chris in a detailed discussion.
I agree that CB's accomplishments don't prove that DD is the only true path to perfection and I can't say how the sound of the 380 might compare with a Walker or Rockport, etc. Perhaps the difference between a 360 and 380 is less profound but I suspect that the increase in snap alone will easily seperate the 380 from the other Teres models. |
One word regarding your question, MJ.
No! :-) |
4yanx,
I can't place either the 320 or 380 in the hierarchy of world class turntables. I imagine they belong there but I don't know the competition at all. Relative to each other, the difference is obvious and convincing. The 380 was easily the best turntable at Chris Brady's house that day. We now have established that one manufacturers only DD is better than his best BD. Does that bring us any closer to a conclusion about the opening question? |
Dan, don't take personal offense, please. My only point is that, especially as one "climbs the ladder" in this hobby, differences (good or bad) generally become a matter of smaller and smaller degree (unless someone totally blows a design or comes up with something truly revolutionary). For there to be THAT much difference between the 320 (the accounts of many claiming it the best table they EVER heard - look up the comments) and the 380 leads me to believe (yes, IMHO) that either the 380 is the best thing since the invention of music (which I doubt) or that the 320 was not all that good to begin with (which I also doubt). |
Ok, how about "humbled"? Anyone is welcomed to go hear these tables and apply whatever adjectives they wish. The point is that once we had gone through the progession of 280-320-380 no one needed, or wanted, to go back and confirm what they thought they were hearing between the 320 and 380. The difference was profound. Macrojack is correct that the difference in tonearms and cartridges does account for a good jump in dynamics. However, this difference does not accout for the superior tempo and attack to just about every note that is reproduced by the 380. It is definitely a Teres, but it is also a Teres with a great deal of snap and live-ness. Chris demonstrated the effect of applying more torque (there is a pot on the controller for this) so there was no doubt in my mind where this increase in performance was coming from. Cb does have some more refinements planned but I doubt these will change the basic presentation. Sorry to use a cliche, but this new Teres does strip away another layer that I doubt any of the other models can touch being as they all use the same motor, controller and belt drive. |
I was there too. Although I left before Dan arrived, I was able to spend a couple of hours with Chris and his son Ryan comparing the 380 direct drive with his 320 and the new more affordable 280. All three tables were quite distinct in sound. I was initially impressed by the appearance of the 380 in that it very nicely finished and to my eye was more attractive than even the drop dead gorgeous 320. The word "prototype" always causes me to imagine some Rube Goldberg contrivance with wires and switches dangling. This piece looked ready for the Smithsonian.
"Humiliated" has a very a malicious overtone to it so I guess I would question it's usage as well, but to say that the 380 completely eclipsed the 320 would certainly be true and it wouldn't sound quite so deliberate. The 380 has a brash and very striking appearance compared to the softer all wood appearance of the other two. But it's sound is more natural, easier and more commanding. There is more nothing about it. While it's appearance is more striking, it's sound is decidedly less conspicuous. Easier and less as if there is any mechanical assistance to the retrieval of signal.
For the minutiae fans, there is room to question the results as there were different arms and cartridges involved, but all cartridges were ZYX and both of the arms I heard came from the top drawer. The 380 had a Schroeder and a Universe and the other two used the Moerch DP-6 and an Airy3.
The only specs I can recall was the weight of the 380 at 135 lbs. and the price as projected should drop in very near that of the Grand Prix Monaco.
Beautiful house and the Brady Bunch were extremely cordial.
They live in Broomfield, halfway between Boulder and Denver and Chris knows his stuff and hosts a really warm party. Get in touch with Teres and see if you can wrangle an invite to the next open house. It was a hoot. |
Dan. The 320 that was just a very short time ago the table to which all others should compare themselves was humiliated? Humiliated? |
I had the pleasure of hearing the new Teres 380 direct drive table (still prototype) last weekend in Dever. I won't say that it answers this question in absolute terms. I will say that Chris Brady has implemented a clearly superior Teres that will probably send many designers back to the drawing board. The 380 completely humiliated a 320 in tempo and gave a very life-like, snappy presentation. Don't pass up a chance to hear one! |
Macrojack: I am staying Belt Driven!!! jejeje, lots of improvement areas elsewhere in my analog setup (arm-power supplies-stands, etc..).
Very interesting thread, a learning experience.
Fernando |
Is it really possible to design the perfect turntable. I think not. I do not agree with Twl, that designers have a hole in their knowledge base. I think it is the knowledge base that has the hole. This and the absence of perfect materials.
Interestingly, were we all willing to convert the signal into digital information immediately, it might be possible for a computer to "remove" non-rigid materials' impacts on sound such as the new telescopes remove the atmosphere's impact on light hitting the mirror. Or remove the resonances of the table, or the LP being off center. All we would have to give up would be analog sound. |
i think it is because turntable designers all have varying degrees of understanding of the entire turntable system, and place varying amounts of emphasis on "perfecting" the various aspects, within a certain price range, and possibly with different technologies and approaches.
It is definitely not a foregone conclusion that just because a company makes turntables, that they are "expert" in the field. And even "experts" have holes in their knowledge base. And even if they do know everything(impossible), they cannot implement perfection, or even close to it at any affordable price range.
So, what you buy is inherently a compromise.
What types of compromising, and how well the compromises work as a whole, will determine the results.
And, since different people have different listening tastes and sensitivities, different forms of compromise may appeal to different listeners.
That's why there are numerous manufacturers, who all provide a different set of engineering compromises, in an attempt to get the best result at the price range intended.
And it's the same with all other components, too. |
|
O.K. Everyone seems to agree that we don't like vibrations and everyone seems to believe that speed stability is of great importance. The only diagreement I've heard has to do with which is more important. Doesn't it seem that bringing them both to manageable levels concurrently should be well within reach given what has already been accomplished?
Likewise it would seem that all of these 3 drive systems are capable of performance levels approaching perfection. So there are three best approaches and none are inherently inferior. Is anyone going to switch as a result of reading or participating in this thread? |
The Technics quartz locked lathe is the standard. |
Tbg...If you want to measure resonant frequency (and I presume Q) there is a straightforward way to do this. You apply vibration to the item you are testing, with frequency swept over the range of interest, and record vibration amplitude of the item under test using one or more accelerometers glued to the item at locations of interest.
You might want to perform such a test during development of the design so as to achieve a non-resonant platter. |
Dear Jean: Thx about the Scully info.
+++++ " The best way to determine speed stability given the problem of which measurements are meaningful, is the human ear. " +++++
The question is: in what range of pitch sensitivity is our ear? how much/less changes on " pitch " can we hear ?
About the statement of Mr. von Recklinghausen, today things are changong about. Today we have better audio designs, better audio parts, better " rooms ", improved know-how, etc, etc. , at least at the high-end audio niche.
Regards and enjoy the music.
Raul. |
Hi Raul, from a quick Google: "scully lathes where made by larry scully. most of them where made in the 40ies and there are still lot of them working. nicely made. optical much more exciting than a neumann the quality was never comparable. althought most of todays "audiophile" records where cut on these lathes.
nice feature of the 1940ies scullys is the inside out leadscrew. you have 2 leadscews. one for cut normal and one for inside out cuts...
the first lathes where all fixed pitch with a gear box. lather models ha a very complicated "vary-groove" mechanism where tube electronics controlled a strange mechanism to varie the pitch.
the biggest disadvantage on scully lathes was the belt driven turntable. with a asynchrounous motor, 2 belts and a heavy clutch the turntable was never that strong and stable.."
Emphasis on "although most of todays "audiophile" records were cut on these lathes." Evidently the cutting lathe technology is no way to tell which is the superior system.
Direct drive is a recent development, early cutting lathes (used to produce records we still listen to and value) used motor-driven gears as well, and its use today in making master discs does not enlighten as to which is the superior system overall, given the presence of assumptions, and the need for the ability to minutely variate the speed of the cutting motor/platter: "Between 1953 and 1955, Neumann developed a method of varying the groove pitch depending on the recorded amplitude. To this end, an additional playback head was mounted on the tape deck. This additional playback head determined the groove amplitude to be recorded approximately one half-rotation of the turntable in advance and fed this value to the cutting lathe as a control signal via a corresponding drive amplifier. Of course, this also required a separately variable pitch drive. For the first time, this made it possible to extend the playing time of an LP phonograph record to approx. thirty minutes."
In playback speed stability in practice, not the ability to vary the speed to accomodate the creation of groove modulations in cutting grooves, is the key. The problem of distortion-inducing vibration/noise is a given and it is the responsibility of the purchaser to correctly set-up any turntable, belt-drive, DD or Idler, suspended or unsuspended, there is no magic bullet. Apparently Van den Hul has his turntable set-up on a concrete pillar sunk deep into the ground! The best way to determine speed stability given the problem of which measurements are meaningful, is the human ear. Back to comparisons in front of witnesses, i.e. demonstrations! Theories must be tested to be verified - or discarded - and the human ear is the final arbiter.
Once again for the Gipper!:
"If it measures good and sounds bad, it is bad;
if it measures bad and sounds good, you have measured the wrong thing."
- Daniel R. von Recklinghausen,
former Chief Research Engineer, H.H. Scott |
Thanks Teres for elaborating. Guess it's a good thing you feel your product development results have affirmed the theoretical reasoning which preceded them :-)
On somewhat of a sidetrack note, let me toss out a bit of theoretical reasoning of my own. I think almost everbody in the business could have it backwards in placing substantial platter mass out near the rim. I know why it's done, but suspect that in a different sense it might be a disease worse than the cure. IMO it could be much better from a resonance standpoint to concentrate whatever mass is required for inertial effect as close to the bearing axis as possible and make the outer regions as light as practical. I understand this would entail use of greater mass overall if one wanted to achieve an equivalent inertial effect. But locating mass very far away from its point of mechanical constraint (the main bearing) is inviting trouble in my estimation. Given that a platter must have a flat top, I think maybe a parabolically-curved underside, yielding a constantly varying thickness, might work well...something like this half-profile:
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(Sorry, the system doesn't permit the full illustration without justifying it, so imagine it mirrored with the bearing axis at the left margin.) Of course the bearing-point itself would be up inside the shape, slightly above its center of mass. Looking at this, I wonder if possibly the York TT that Fremer has sometimes pictured in his column might not have a similar platter profile, but I don't really know and can't think another myself. But if it does, that makes more sense to me than the common approaches. End of off-topic musings... |
Dear friends: There is other point that " speaks " in favor of the DD system:
from what I know the cutting lathe machines ( that " make " the LP ), like Neumann, Fairchild, Scully, etc, etc, has DD design not BD/IW. Wonder why?, yes you have the answer.
Regards and enjoy the music.
Raul. |
As a proponent of the "niche market" rim drive group, I would suggest that Eldartford omits probably the most important character of the TT-resonance frequencies. I grant that he does mention vibrations. My real question, as always, is how do specs. capture this. Again as always, all I want is to hear the TT. I did hear the Shindo/Garrard 301, and I bought it.
I should say that regardless of how good it sounded, putting it on the Halcyonic base greatly improved it. Again resonances. Would it not be great to have freedom from resonances. |
Specs...It is obvious that the sonic character of a loudspeaker cannot be defined by specs, although some things like frequency response can be usefully measured. However performance requirements of a TT (not the arm/cartridge) are so simple that I think that specs can tell the whole story.
1..A TT must rotate the LP at exactly correct speed, and without speed variation for reasonable stylus drag force variation.
2..A TT must not generate a magnetic field at the cartridge.
3..A TT must not generate vibration, for example rumble.
4..A TT must attenuate vibration of the base it is mounted on.
All these can be accurately measured. The only issue is to determine what acceptable values might be.
And remember that the real reason for specs is for the manufacturer to verify that each unit he builds has been properly manufactured and assembled so that it performs as well as the design permits. Use of specs to assess the quality of the design is something extra that people do with specs. It is more valid for TT than for most other audio equipment. |
Perhaps the original question should have been: Why do belt drive turntables have a reputation for better sound quality than direct drive turnatables? (This ignores the rim drive fans who are definitely a niche market group). With the question phrased like that the answer becomes much clearer. It is in two parts:
1 The Linn/Naim axis in the 70s did a superb job of marketing the Linn LP12 to such an extent that the audio press started to doubt their own ears. The result, only belt drives were worthy of audiophile ears.
2 The japenese giants saw DD as a way of producing TTs cheaply and sacrificed sound quality in name of the God profit.
As a result the point marked 1 became a self fulfilling prophecy in the domestic market. It was only in professional markets (broadcast studios etc) that the true benefits of DD were realised.
Which is better? Neither, each has its own pluses and minuses. Execution is all in the quality stakes. It is a fact that the domestic turntable development suffered irreputable harm at the hands of the Linn/Naim hysteria of the 70s. (That and the arrival of CD) stiffled the development of the TT.
One last thought: I would never buy a turntable without specifications, not because the specs dictate the neutrality of the sound but because if I am to lay out hard cash I want to make sure the manufacturer is not ripping me off and I have something to bash them with if my purchase does not measure as it should |
I was sincere in my question to Teres -- not pessimistic, only a bit prodding. I think it's possible to do both (good marketing and good design; there's nothing wrong with the former as long as it serves the latter), I just sense he's downplaying the reasons why Teres is, in your words, taking "a huge gamble". For all the reasons you list why this wouldn't be undertaken lightly, it's hard to conclude anything other than that Teres does believe that DD holds more promise in some important way(s). I want to know why. |
Zaikesman, I have to admit that the direct drive choice was based almost entirely on theoretical reasoning. The initial quest was to produce a better quality motor using some new techniques that I had been musing about for some time. When examining drive methods it looked like DD had the most potential (ie lack of compromises). But at the same time it also looked like the most difficult and risky approach. A little isolation can cover a lot of motor sins and with DD you get none. I also looked closely at idler drive. From a theoretical perspective it seems that idler drive is somewhere between BD and DD. Some isolation but less than with BD. I happen to think that idler drive has a lot of potential and suspect that at some point I will experiment with it.
In the end I settled on DD because I believed that this new motor would have low enough torque ripple that DD could be used without compromising the smoothness that is characteristic of a good BD table. Our first DD incarnation confirmed my theories. It had great pitch stability, drive and rhythm but sadly lacked smoothness and refinement. But with some considerable effort the smoothness and refinement has now surpassed our best BD motor. So is the success due to the motor or the drive method? The answer must simply be yes.
Fortunately, or unfortunately, marketing had little to do with the decision. It's going to be difficult to recoup the development costs for the DD motor. Sadly the motor is expensive to produce so I doubt it will ever be sold in volume. But I can say that it has been one of the most personally rewarding ventures I have embarked on. |
P.A. may be waiting for me to apologize for calling him psychotic although, if he really is psychic he surely knows I meant no harm.
I've assumed from first hearing of it that Teres is looking to raise the bar not the bar graph. If Chris was looking to sell more tables, he'd be designing Teres Jr. for mass consumption rather than some ambitious project that I won't be able to consider buying. |
Zaikes, if you think about for a minute, moving to DD for marketing reasons alone would be a huge gamble (some might say insane), to say the least, from a business point of view. I've worked for start-up companies for almost 12 years and I can assure you if you swim against too strong of a current you will drown quickly. Chris can certainly speak for himself, but based on everything I've heard about him I doubt there is anything short of a sincere desire to improve the current state of the art being offered from Teres. Healthy skepticism is a good thing, pessimism is another issue. Especially when it is expressed from a position of absolutely no first hand knowledge of the table in question. But you are entitled to your opinion. I'm not trying to throwing darts at you, maybe just spill a little beer on your foot. :) Where did the animal go? |
