Jean, Are you talking about the distal end of the idler arm, where it attaches to the chassis, originally with rubber washers on either side of the nut/bolt that hold it to the chassis? Ugghh, I'll have to remove the chassis from the plinth to do that one, always a thrill. |
I suppose I'll get slammed for writing this, but I have had a lot of exposure for the last 10 years to my friend's Well Tempered Reference table and arm, and I find nothing there to yearn for. The sound is invariably overdamped and unexciting. And mounting a cartridge on the WT tonearm is a nightmare such that I noticed on a recent visit that my friend has given up trying to mount a Dynavector 17D3, after buying a Feickert protractor for that sole task. The headshell has round holes rather than slots, so the only way to adjust overhang is by loosening the screw that binds the vertical pivot shaft which permits rotation of the tonearm at its base. Problem is that the screw is located in a deep recess under the chassis; it's near impossible to get overhang correct and then tighten that screw without destroying the set-up. I know this is irrelevant to the thread, but I am upset about it on behalf of my friend. |
Well, we're using the Lenco chassis, and most of us are not using the Lenco tonearm and plinth, so it's not really a fair comparison to the WTR. But by any standards, the WTR w/tonearm is very difficult to work with if one wants to change cartridges. Also, the sonics don't hold a candle to any Lenco I've heard. In fairness, the WTR may have had a design upgrade in the 10 or more years since my friend bought his. Current models may be easier to use. I do think that the basic table is a very interesting, even brilliant, design among belt-drives. It's the tonearm that I dislike. And the design is such that without modifying the table one could not hope to use any other tonearm with it, except maybe an RS-A1. As long as I'm posting here and to get back to the topic, has anyone heard a Lenco in a slate plinth? |
Jean, FYI, Raul Iregas had an SP10 mk II in a marble plinth and did not like the results. He "reverted" thereafter to a simple and not very heavy wood plinth (maybe made of Baltic Birch), and that is what he uses with the SP10. Two qualifiers are: (1) This was a Technics SP10, not a Lenco. The optimal plinth for a direct drive may be different from that for an idler, and (2) we don't know much about Raul's marble plinth except he did state that it was very heavy (100lbs?). Perhaps Raul would care to comment.
I've often wondered what is the point of the ping test in selecting materials for audio use? It seems to me that a good shelf or plinth material should be a material that is able to dissipate the vibrational energy put into it, as heat. There is a large body of knowledge in materials science as regards the ability of energy to pass from one material to another. (Some is reflected back and some is absorbed at each interface. When the energy pulse reaches the far boundary of the absorbing material, some of it is reflected back again toward the admitting surface.) So the question is how does the plinth or shelf material mate with the metal chassis of the turntable and then from there what happens to the energy that does get into the plinth. You could have the deadest substance on the planet, but if most of the energy from the tt chassis is reflected back at the interface OR if the mating is suboptimal in any way, the plinth is worthless. Maybe that's why marble failed in Raul's experiment. As for me, I am fairly satisfied that undamped granite sucks as shelf material, for another example. I would definitely not consider granite for a plinth. |
Dear Jean, With all due respect, and speaking as a happy owner of one of your Giant direct-coupled Lencos, I must nevertheless take issue with some of the bald statements you've made in this last post, many of which are repeated from previous posts. First of all, a quartz-locked drive system is naught but a servo system that is referenced to a quartz crystal oscillator. The quartz reference idea came along much later than the servo per se and was thought to constitute an important advance. With the quartz reference, the servo works better, not worse. (For example, the Micro Seiki DQX-1000 dd table is said to be superior to its predecessor, the DDX-1000, based on the quartz reference that distinguishes the former table from the latter.) Having said that, it's quite possible that you are correct in your ranking of the relative sound qualities of the various dd tables you discuss; your opinion carries some weight with me, because I believe you've actually listened to them all. However, your reasons why one dd table might sound better than another are pure speculation and should be labeled as such. (You invent an hypothesis to suit your listening results; this is bad science.) If you've done any actual experiments to compare a servo-drive with and without its quartz reference in the context of a given turntable, I'd sure like to know about them. (This is possible with my Denon DP80, and I intend to try it.) I just hate to think a newbie is swallowing the whole enchilada, so I felt it necessary to make a comment here. No animosity is intended. Carry on. |
Rnm4, you are correct. I misspoke. I should have written that Jean does propose his hypotheses as facts, without having done the experiments necessary to prove the hypotheses, as you also suggest. Or if he did them, he does not present the data. |
Rnm4, I have and had no intention of starting a fight. All I'm saying is that when one says X is due to Y, Y ought to be true. If Y is not true, then it cannot be a cause of X. Without being specific, I take issue with some of Jean's Ys (his presuppositions). I did write the first time that by all means Jean is entitled to his opinion of these different dd turntables, and that in fact I respect his opinion as a good listener and one who has done a lot more critical listening than I have. |
Rnm4, The same goes for me. I only wanted to enliven the discourse. There's really no way that Jean could have an underlying motive when he states that he likes the Technics SP25 better than an SP10 MkII; I hope it's understood that I also think that this is a non-issue. I just wanted to talk a bit about what does or could possibly cause the differences in sonics among the dd's that Jean mentioned. |
Gad, Is the Thorens TD-111 an idler? Have you restored or repaired it? If so, why not enlighten us? Perhaps you have something to teach us, other than how to make snide remarks. I can't recall your ever having made a useful contribution here, but perhaps I am wrong, since I am a late-comer to the faith. |
JLoveys, If your early expts excite you, check out the PTP2 top plate for the Lenco (on the Lenco-Lovers website). Not only is it far more rigid than the chassis of either a stock Lenco or a Garrard, it also permits a large area of contact between itself and the top surface of a slate or wood plinth. I myself have one but have yet to make a plinth for it. For a tonearm to compare turntables, I bought a 47Labs RS-A1. No mounting is necessary, so you can rapidly move the same tonearm and cartridge from one table to the next. |
Hi Peter, What's up with your bearing assembly project? Given the large positive effect that the Kokomo bearing reportedly has on the sound of the Garrard 301, I am waiting with bated breath for your new Lenco bearing. |
I did, too. It finally worked. |
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If any former Lenco-Lover has copied Peter's photos showing how he assembles the PTP3, I would be most grateful if they could be pasted in here or in Lenco Heaven. Maybe Peter would re-post them himself. Also, the threads on adjusting, restoring, etc, the motor were invaluable. |
Hey Jean, You were going to tell us about some new ways to reduce resonances in the stock chassis. What's up with that? Also, how are you doing with Peter's PTP? |
Nothing like a good, firm bottom, I always say. |
Re isolating the motor: that is one of the major benefits of the PTP3 in a slate plinth, IMO. And that solution does not require any Rube Goldberg devices in between the motor and everything else. (Rube Goldberg was an American cartoonist who made his mark by depicting unnecessarily intricate devices, often involving animals, to be used for simple tasks, in cartoon format.) |
Hi Ian, Very nice job on your slate plinth. I see you are also using an RS-A1 tonearm. I have one, too. It's a great choice for a slate plinth, because no drilling is necessary to install one, not to mention that the sound is excellent despite or because of the weird mechanics. I have my slate cut, and I have the PTP3 kit and a "donor" Lenco L75. I just need to seal the slate, paint the PTP3, and then bolt it all together.
I wonder what Jean is up to these days. |
John, You wrote, "Panzerholz (it is for all practical purposes unable to store energy, that is, dissipates energy almost in 'real time')" What are the data that support that statement? Or have you used a bit of hyperbole? I ask in order to gain some knowledge, not to challenge you. |
John, Apology not necessary. I just wondered whether anyone HAD applied a scientific approach to this otherwise completely subjective and empirical endeavor. There are many reports from various sources that suggest that Panzerholz is a great material for plinths, etc. For example, Albert Porter has made some Panzerholz plinths for the Technics SP10 that are said to sound excellent. |
I have my doubts or questions as regards inserting a layer of alu or other metal midway in a wood plinth. The danger is that one may be creating an internal reflective surface that will bounce energy back up toward the turntable, instead of permitting it to dissipate in the nether regions of the plinth. (At the interface of two dissimilar materials, energy is transmitted, absorbed, or reflected, depending upon how the two materials interact with each other. This effect is governed by a constant for the two materials that is called the "coefficient of transmission" or something like that.) It all depends on what happens at the panzerholz/alu interface. And that I do not know. |
Etch, Glad you solved your problem, and I apologize for the humor at a time when you needed help. However, I am hard put to visualize how you could have "knocked the bearing out" while removing the platter. Did you whack the spindle too hard when trying to free up the platter? And for a serious response to your earlier dilemma, I strongly recommend anyone to visit the McMaster Carr website and go to their section on springs. Surely one could find a suitable substitute spring from their vast selection. Even if you don't want a spring, McMaster/Carr are an invaluable asset for hobbyists. For reasons that now elude me, another knowledgeable Lenco-phile told me he prefers a real spring to an elastic, despite the fact that a few of the gurus on Lenco Heaven are using elastic.
On another note, a few days ago I completed assembly of my Lenco/PTP3 in an 80-lb slate slab. It took a long time to complete because I was trying for a professional look. (Did not quite get there, but it's nice.) This weekend I hope to create enough shelf space to mount it in my system next to my two direct-drive tables. Dave, I am almost ready to get you over for an audition. I think it will rock. Where the heck is Jean? |
We are waiting for the Messiah.
Meantime, you could go to Lenco Heaven. |
Dear Gp49, Have you seen a photo of the actual tt that Salvatore is listening to? If so, does it retain the original Lenco chassis, or has the chassis been ditched in favor of the Peter Reinder's PTP? I ask because I think the PTP makes a big improvement, bigger than any replacement bearing or after-market idler wheel, provided the original bearing and idler wheel are in primo condition. IOW, Salvatore may not yet have heard the best possible iteration of the Lenco. With the PTP, you don't get day to day changes in speed if everything is fastened down as it should be. And of course the motor is much better isolated from the bearing and platter. |
Dear Jean, Is your bearing upgrade available to the rest of us? If so, can you supply details? Also, do you still use and recommend the stock idler wheel in your ultimate efforts? Thanks. |
I certainly would not want to argue the question of whether this new mod actually improves sound quality, which it may well do, but on the level of theory, I have a question: Why would one expect the string not to transmit vibration, as compared to a spring? Sources of vibration could be (i) the bearing of the idler wheel, (ii) irregularities in the shape of the motor drive shaft, or (iii) dirt or other on the underside of the platter that might cause the idler wheel to bounce a bit. The force applied by a spring to maintain contact between motor shaft/idler wheel/platter will vary according to Hook's Law, which says that F is a linear function of the amount of stretch of the spring. The force applied by the string to do the same would be equal to gravity less any frictional losses where the string touches anything. I don't get why (theoretically) the string would obviously be a better way to do the little bit of work (small force X a very small distance) that is required. I guess you are saying that the spring itself is a source of noise/vibration that mucks things up; yes? |
Dear MikeyC8, If your platter continues to spin for more than 4 hours after a manual push, see your doctor.
Dear Gouldglen, You are quite a gadfly. Win is one of the best guys in the business, and he knows full well that the cost of his masterpiece places it out of the reach of most of us. So what? Both Win and Jean are idealists and advanced hobbyists who took their passions beyond the basement level, and we all benefit from that, directly or indirectly. |
Thanks, Trav. I did visit Heaven and did see the photos you mention. It looks kind of crude to me in that the string is passing over two abrasive metal surfaces. I would rather go Jean's way, drill a new hole (as you evidently did do) and line it with some sort of ceramic or brass grommet so the string only passes over the smooth side of a single grommet. That's if I ever get around to trying this mod. I am impressed with the unanimously favorable reviews, but I want to know more about the why of it. That's just me. What about unscrewing the post that holds the end of the spring, and using the hole thus made available for the string to pass thru? That would be simple as simple can be, and it would preserve the factory-determined vector of the force pulling on the idler arm. Unless that hole leads to solid slate on my turntable. |
Has anyone here done this mod with Peter Reinders PTP? Or are you all using the stock Lenco chassis as a basis? If done with PTP, did you have to drill a hole to accommodate the string and weight? Thanks.
Jean, in your earliest posts on this mod, you seemed to think that the benefits had a lot to do with eliminating a resonance imparted by the spring, Here you seem more to focus on the benefit of increasing the force that marries the idler wheel to the platter and motor shaft. Have you changed your mind about how the string works to improve the sonics of the table, or am I over-interpreting your last post? |
Dave, How much weight did you use? Thanks. |
Forgot you said you used his kit. Thx anyway. I have figured out how to implement the string in the context of the PTP without drilling new holes. So I will (reluctantly) give this a try using small lead or brass weights. Does anyone know how much weight he (or she) used to achieve Nirvana? |
I am still breaking in the Jeremy bearing plus clamp, so any improvement due to the string might be hard to decipher, if I added it at this point. I will do some listening to the Jeremy this weekend and then maybe do the string next week. But I will say that my Lenco already competes with, if not beats, some other expensive stuff I have lying around here, so I can only wonder at the superlatives I read above as regards the string and weight deal. |
String Theory. The factory installed idler arm spring pulls the idler arm not only up toward the bottom of the platter but also exerts a force slightly biased toward the spindle side. I guess this is because the idler arm actually describes an arc with a radius equal to the distance from the rim of the idler wheel to the fulcrum of the idler arm. In replacing the spring with string, have you guys mimicked the angle of pull of the spring, or have you (or does Jean's kit) mount the string so that it pulls with a force in parallel to the rim of the idler wheel? Thanks. |
Fourth and probably most obvious source of vibration of the idler wheel: Deviation of the idler wheel from perfect round-ness and roughness at its contact surface. The spring or string may or may not be the major player in maintaining contact among drive shaft/idler wheel/platter, as idler wheel bumps along. A knowledgeable friend of mine thinks that the idler wheel is held in place primarily by the platter/drive-shaft "squeezing" effect, as both of those rotate, i.e., the spring or string is pretty much out of the picture once power is applied to the motor. Dunno about that. Still don't see how the spring can do much that is bad, once the platter is turning.
This is not to say that the whole idler wheel, idler arm, and spring set-up could not be improved upon, but I think it would require a radically different approach. Win Tinnon has done that in his Saskia, but he won't say how, and I don't blame him a bit for that. |
