Dear Nandric, I have met Thom Mackris a few times, and we exchange emails occasionally. I hold him in very high regard. His turntables are works of art that employ very heavy plinths that do not have a "deck" surface surrounding the platter. I have long thought that this is the best way to go for belt drive. His tonearm support structure is very firmly linked to the subchassis. He does not use separate arm pods at all. So his approach to design would agree more with my ideal than with Halcro's et al. I do not know anything about Mr. Lurne or his current products. I had some experience with one of his early turntable efforts many years ago, and frankly I was not impressed at all in any way with it, except its cost. I am sure his work is much improved if you like it. Anyway, one cannot "prove" that one design approach is superior to another by simply naming names. In the commercial market, there are all kinds of turntables, and they sound good and bad. Your own Mr. Kuzma makes great products that fit either description, Copernican or the other. |
Hey Chris,
You can always elevate your turntable by putting some big tall feet under it, to enable you to use a more massive pod. How about that Vyger turntable? The pod would be 4 feet high or so, judging from photos. In brass, that would be significant mass, I'd say.
You made me think of this, because I have just recently elevated my Lenco in its slate plinth, not so I could use a massive arm pod but in order to accommodate some "feet" that I made out of cans of Mandarin Orange slices in water, sitting on tiptoes. In my rationale, the closed system of Orange slices floating in water helps to dissipate energy (by sloshing of the water damped by orange slices) going from the floor up into the shelf and hence into the slate. For $6 plus the tiptoes, which I had on hand already, it "works a treat", as the Brits like to say, and if you don't like it you can eat the Mandarin Orange slices, for another kind of treat. |
Cantaloupe? Where do you ever see canned cantaloupe? I toyed with the idea of stewed tomatoes, peas, corn, etc. Anything that is sloshing around but has some substance. Cantaloupe might work if the water content is high enough. Note that I am taking your response seriously. Not.
Soon I will mount photos of my anti-no-plinth, made to my design and then assembled by me for my SP10 Mk3, using a huge slab of slate bolted to a substantial wood base made from solid cherry and baltic birch and with a brass billet imbedded under the table to dampen any bearing vibrations via connection of the bearing housing to a brass rod which screws into the brass billet, a la the Albert Porter idea. It weighs about 90 lbs without the SP10 installed. The wood base really adds substantial further dampening to the slate. You guys would hate it. |
Chris, IMO, as long as the Jr's come to rest at the same exact spot every time, you should be OK with that novel set-up (by my standards). And the high mass helps that to happen. High precision of the manufacture of the Jr's is also imperative. |
Banquo, Good to know that you finally found peace with Bill Thalmann. I don't know how you (and others) are managing to use more than one outboard pod with the SP10. The square escutcheon that surrounds the platter really interdicts the use of more than one tonearm, which must be placed alongside the right-hand edge of the square, which allows a short enough distance to the spindle to permit alignment of a 9- or 10-inch arm. From all other sides, perhaps only a 12-inch arm can be aligned. But obviously you are making it work, somehow. The Denon tt's present no problem in this regard.
Nandric, Removing the bottom of the SP10 chassis would be a big mistake, IMO. It would reduce structural integrity of the whole, leave the on-board electronics open to the elements, and eliminate any way to provide a solid mount for the tt. |
To all of you plinth-less persons, it is possible and permissible to do something different from what Raul does and still get satisfactory results. Think outside Raul's box. The AT616 feet may be good, but they cannot possibly be the only "good" option for feet. Also, I wonder what you are all using for platter mats. I found the stock rubber mat supplied with my SP10 Mk2A was easily bested by an SAEC SS300 metal mat (purchased from Raul, by the way), and I am sure other mats would also be superior to the rubber. One that I aim to try on my Mk3 is a Boston Audio Mat2. The Mat2 has about the same weight as the stock rubber mat and so should have no deleterious effect on function of the servo mechanism. (I don't recommend a super heavy mat for that reason.) My experience tells me that the stock rubber mat may be responsible for the the closed-in, grayish, dull tonal quality that some have ascribed to direct-drive turntables. (I have seen each of these adjectives used; take your pick.) I even think that the stock mat may have more to do with the tone than does the plinth or lack of same. |
Dear Banquo, Your remark directed to Halcro speaks honestly to one point I have been trying to make with the plinth-less crowd. The torque of an SP10 motor (Mk2 OR Mk3) is sufficient to move the chassis, if the chassis is unfettered by a plinth. Thus I would fear in theory what you may be observing in fact, that your turntable may be able to "walk" away from correct alignment. I think this is fixable by maybe using double-sided tape between the bottom of your chassis and the top surface of the AT616 footers. Of course, I personally would fix it by building a plinth or some sort of substantial anchor for the chassis. I recently read that the servo mechanisms in these turntables apply full torque instantly, each time they are triggered by a speed variation. Heretofore, I thought the motor controller via the servo system could call up "just enough" torque to return the platter to correct speed, when needed. If that were true, the effect of torque to move the chassis would be minimal during actual play. But now that I have learned that the servo simply gives a full on or full off signal to the motor, I am even more convinced re the value of a good plinth. By the way, I did not mean to imply that you (personally) were dogmatic re AT616 feet, but there seems to be a general trend in that direction among other disciples of the Copernican approach.
As regards the tendency of an LP to slide on the surface of a Boston Audio mat, I have observed the same thing. I use a Mat1 on my Lenco. The Mat1 had a tendency to slip against both the surface of the platter underneath it AND against the surface of any LP on top of it. I finally cured the former issue by inserting a few slivers of double-sided carpet tape between platter and mat. Just small pieces were sufficient. As regards the tendency for LPs to slip, I too notice that when using a carbon fiber brush to remove dust from the surface of an LP prior to play, but it does not seem to be an issue during play at all. You might want to try an SAEC mat; they are often for sale on eBay and Audiogon for around $300. No slipping issues with SAEC. But based on what I hear from my Lenco, I think the Boston Audio mats may be (even) more neutral sounding than the SAEC. After hearing either one of these mats, I could never go back to the OEM rubber mats. And I am sure there are other candidate mats that would best the OEM ones. This was very true for my Denon DP80 as well. The OEM Denon mat might be even worse than the Technics one. (Alas, the Denon sits, loved but unused, on a shelf in my basement.)
Dear Ecir, Idler-drive turntables need to be mounted in well built plinths for best performance, IMO. I think that is much less controversial than the use of a plinth with a direct-drive. I don't think you will ever get the best out of your Garrard without some sort of plinth. |
Dear Nandric, just to set the record straight, the Boston Audio mats and the SAEC mat are very near in weight to that of the OEM Denon and Technics rubber mats. What I was saying in my last post is (among other things) that these two types are perfectly acceptable. I am not "worning" against their use. However, some folks use other mats that weigh as much as 4 lbs (2kg) and more on the Technics. IMO, that is too heavy. Others disagree.
Dear Ecir, Sorry I misunderstood you.
Sorry neither topic refers directly to outboard armpod use. My standing comment on that is if you are going to do it, I think both the tt and the arm pod need to be on mounts that are similar, if not in fact identical, in their tendency to transmit or dissipate mechanical energy of all types. You do not want the the tt to be jiggling (even on a micro level) whilst the arm pod is static, or vice-versa. Since this issue is created by using a separate arm pod, it also forms the basis by which I reject the outboard pod notion entirely. I know I am boring on this topic. |
Brad, Beautiful stuff on that website. Thanks for the URL. I am drawing ever closer to a high efficiency, high impedance spkr system, if I could find one that I both like and can afford. |
Yes. Love my DV505 so much that I have two of them. And then on top of that a dear friend (my longest term audiophile friend) gave me his DV501 last year. The DV501 was introduced shortly after the DV505. It is very like the 505 except that it lacks a few doodads, so it could be marketed for a lower price. DV501 uses counter-weight balance instead of dynamic balance, lacks the little spring-loaded resonance-reducing gizmo that is tucked up under the horizontally pivoting part of the 505 and 507. Some liked it better than the DV505. I preferred DV505 to 507 because the 505 can be surface-mounted; you don't have to drill a hole in your armboard or plinth to accommodate a vertical shaft that goes below the top surface of one or the other. When I built my early slate plinths, I decided to limit myself to surface-mount tonearms so as not to have to implement removable arm boards. The fully developed Mk3 plinth does have a removable slate or alu armboard, however, can use any tonearm of 10 or more inches effective length. |
Dertonearm. Yes, before your protractor existed I had aligned my DV505 on my Lenco using Baerwald. The cartridge had to be twisted inward in the headshell, and the sound was not so good, which I tended to blame on the cartridge, since it was my first time hearing the Lenco, the DV505, AND this particular cartridge (which I think was the Ortofon M20 FL Super). However, when I finally found a Stevenson protractor (for free on Vinyl Engine) and used it to re-align the cartridge, things got a lot better. I concluded that the DV505 was designed for Stevenson or something very near it. |
No. I will stick with Stevenson for DV. In fact, this experience (Baerwald vs Stevenson on the DV505) was a good lesson for me on the importance of geometry.
And now, back to your local Copernican view. And as Thuchan says, "all in fun". |
Dear Nandric, In regards to your post of 08-10-11, I think that the maker of the tonearm, by selecting the offset angle of the headshell and by selecting an upper and lower limit for effective length (the margins for this being equal to the length of the parallel slots in the headshell that permit fore and aft movement of the cartridge), has pari passu selected for us an optimal geometry. We (the end user) are largely denied the luxury of deciding for ourselves where we want our null points with respect to innermost vs outermost grooves. Unless of course one wants to put up with distortions created by forcing an inappropriate geometry to be made to "work". In my experience of N=1 it is best to go with the tonearm designer. |
Dear DT, It's relevant to this thread only in that it points out the critical nature of tonearm alignment for those who wish to use outboard arm pods that are free to move about in relation to the tt spindle. (I will now don my armor plating.) |
Dear Ct, Henry, and anyone else who is disturbed by my occasional digs at your approach to tonearm mounting: Believe me when I say you have my blessings in whatever you do, and I enjoy reading about the construction of the various pods. The fact that I have not tried it and may never try it is not a sign that I am a troglodyte; it merely shows that my plate is very full with other projects that have to take precedence, not to mention going to work every day. Altho you know quite well my theoretical objections to arm pods, which are largely the same as Dertonearm's, I am sure that an outboard arm pod can sound perfectly wonderful. I also think all of us can tolerate much more in the way of imperfections in our music reproduction than any of us cares to admit, so I doubt I would hear it if my arm pod were to "walk" a few mm in one direction or another with respect to my tt. I am very happy with what I have in the way of tt's right now.
Nandric, Did you tell me that you own a Kuzma 4-point tonearm? After reading Fremer's review, I am interested in that device. |
Dgob, One advantage of brass: it is pretty soft and therefore very easy to machine. It also looks nice.
Can someone point out to me where (in what post) JCarr listed his preferred materials in order of goodness? I only see where he listed first the preferred methods for creating objects out of solid metals and in a second post the metals that he personally has auditioned. Or Jonathan? Thx.
Daniel (DT): Do you equate speed of the propagation of energy in a material with goodness of the material for use in arm pods, plinths, arm boards, platters, or what? |
Dear Jonathan, I guess I am in good company. When you wrote, "...a more elegant, and technically correct solution is to mount the tonearm pivot and platter / spindle onto a single rigid structure that allows everything to move together at the same rate and same distance (and phase), then isolate the complete system from the environment by means of an isolation platform (not footers)", you pretty much echoed my position on the subject. Thanks very much for taking your valuable time to respond.
One thing though.... chocolate IS better than tomato, except at this time of year when our tomato plants are producing great tomatoes faster than we can eat them, thanks to my wife. |
Dear Travis, Once you couple a high mass arm pod to the plinth you likely have a very good set-up. That's what I would do if I ever build an outboard pod. I never would argue that basing a tonearm firmly in a stabilizing high mass is not a good thing. Look at those optional weights made by M-S and SAEC to stabilize the vertical shaft of their tonearms where it passes through the mounting board. That seems like sound engineering to me. I have made some brass pieces like that (to go under a mounting platform) for my DV505 and I plan to do it for the Reed and/or Triplanar. |
I have to admit that I am impressed with what I have seen in all these photos. Obviously this is a serious exercise. The Da Vinci!!! OMG! Wretched excess, thy name is Leonardo.
Since TT Weights stuff is almost always available at a discount, and since they are incredible machinists, I would go that route absent the availability of a fine machinist to custom-make one for me. |
The Reed tonearm was an incredible bargain, even on this side of the pond, when it was first introduced. Then they evidently realized that based on performance it was under-priced. That, and also foreign distributors and their need for a separate profit margin entered the picture.
Just looking at the Da Vinci turntable cum armpods, I can understand why J Valin and M Fremer are big fans. Neither of them ever met a gilded lily he did not love. The more pompous, the better it must sound. |
One nice thing about the cantilevered armboard is that one can fine tune the spindle to pivot distance without having to shove around the huge main weight of the whole pod. I think this is a tremendous advantage in obtaining mm accuracy. And I don't know why there would be any danger of tipping or even tippiness; the weight of the main body of the pod would easily be many multiples of that of the cantilevered armboard cum tonearm. Another advantage is that one need not accommodate the vertical shaft of the tonearm in the main body of the pod itself (as Henry has cleverly and probably expensively done); it can hang there in space next to the pod, so you can easily fiddle with tonearm ICs, etc. And finally, such a set-up would be very cheap to make and require the minimum of machine skills, IMO. All you need is a brass cylinder, perhaps threaded at the bottom for "feet", a threaded hole in the top dead center of the cylinder to affix the cantilevered armboard(s), and probably an alu or brass or bronze or wood or whatever armboard with a hole at one end for bolting to the cylinder plus a hole at the other end sized to fit the tonearm in question. I really am enthused now; I would make that brass cylinder as large and heavy as possible. Note also, thou plinth-less ones, the size and mass of the bass on that Da Vinci and how the base of the tt is an exact match to the bases of their armpods, so as to provide similar levels of isolation/coupling to the shelf. This is the way it should be done, even if the Da Vinci is "showy". |
T_bone, Why not use an actual M-S armboard (if you are using an M-S tonearm)? I think reproductions are made.
Halcro, You are obviously an architect. (I already knew that.) But doesn't all cement shrink to at least some degree whilst it is setting up, no matter how low the water content? And wouldn't even a small amount of shrinkage cause the inner cement cylinder to pull away from the walls of the metallic tube? Thus, could the cement cylinder become loose and actually fall out of the tube?
By the way, this issue of "shrinkage" was covered in a Seinfeld episode. |
Dear In_shore, What you say is also well and good. I further still maintain that the tt and armpod ought ideally to be in unison, so use similar strategy to isolate both tt and tonearm, a la the Da Vinci. I would not favor using a Da Vinci or similar armpod with a tt that was sitting on AT616 feet, even though I know that others here are doing something akin to that and getting what they interpret to be great results. I think that might mean that the level of our concern regarding structure borne and internally generated forces amounts to massive overkill. |
As time and my birthdays go by, I feel I am headed toward a Linn turntable, a solid-state integrated amp cum phono stage, and a pair of bookshelf speakers. My muscles and joints would love that system. Last night I had to carry just the power supplies for my new Sound Lab 845PX speakers up from my basement to my listening room. This awakened symptoms due to an old rugby injury to my cervical spine. It took four of us to uncrate the 845s and carry them into the house. (I timed their arrival to coincide with a visit from my son, from Tokyo, so I could count on his help.) I cannot lift my SP10 Mk3 in its 100-lb slate and wood plinth without assistance and can barely lift the L07D. I don't look forward to carrying my 90-lb tube monoblock amplifiers up the steps from my basement to the listening room, either. This is despite the fact that I lift weights, do push-ups, and do a cardio work out every day. This talk of massive pods and plinths puts me off, even though I subscribe to the theory. High end audio is for young athletes or for those of us with grown sons who have not yet left home. |
Dear Nandric, I am working at this point because I still need income, not because I am too young to retire. The speaker maker, FYI, is called "Sound Lab". They are located in Utah. The full name of the product I bought is "Majestic 845PX", a fairly pompous name, as I am sure you would agree. They are basically giant full-range electro-static speakers. I have a lifelong love/hate relationship with ESLs driven by output transformer-less (OTL)tube amps. I sent my old smaller Sound Lab M1s back to the factory for rebuild, and while they were away got a great deal on the 845s, an offer that I could not refuse, if you have seen The Godfather. While all this has been going on, I have been listening to Quad ESL63s for several months. That's a speaker more suitable for someone in our age range with a bad back. I know this is way off-topic, but it explains why I cannot think about messing with arm pods or de-plinthification (thank you, George W Bush) at this time. |
Raul, It's a bit of a secret, but I am on to a way of modifying the input of the Sound Lab so as to render it quite nice for my OTLs and anyone else's tube amps, as well. This is a collaboration among several Sound Lab users who prefer OTLs and/or tubes. To take a page from your book, I can't say any more than that right now, but I am listening to a primitive form of the final solution, and it is already a big improvement. I agree, the OEM Sound Lab is built for high power solid state amps, but it does not have to be that way.
OTLs are fine when driving a high impedance load. "Damping Factor", a term that SS amplifier makers love to bandy about, is a non-issue with ESLs. An ESL speaker does not develop a back EMF that needs to be opposed by a very low output impedance amplifier. In any case, Z at very low frequencies is very very high with an ESL. High enough to constipate many solid stage amps and to be ideal for OTLs. |
I plan to mount my amps on separate arm pods. I will require 3 per monoblock, of course. |
Dear Dgob, When you say that you found "improved performance" when you mounted your nude SP10 on AT616s, may I correctly assume that you refer for comparison to the same tt when mounted on Symposium products? Or what? Thanks. |
Nandric, If one wishes to drive any of the full-range Sound Lab spkrs with a tube amplifier, particularly with an OTL tube amplifier, there is work to be done with the network that feeds the panel. I and others have made some modifications that help a lot. The stock OEM speaker is probably fabulous right out of the box with a first rank solid-state amplifier, but its impedance curve is treacherous for an OTL. |
Dear Audpulse, With all respect, the Berning ZOTLs are fine amplifiers, but they are not OTL amplifiers in the normal sense of that acronym. This has all been argued ad nauseam, and I am with you, if you were to say it does not matter. What matters is they are very good sounding amplifiers designed by one of the true geniuses in audio.
Halcro, Is the SP10 as stable as you recommend to Chris that it needs to be, when mounted on AT616 feet? How would that be unless there was some sort of physical anchoring between the SP10 chassis and the tops of the feet? (You are not the only one who knows how to use a question mark?) |
Yes but Henry what's your answer to my valid question? |
Dear Raul, I have read not one word that persuades me that I am missing something important by denuding a turntable or using an armpod. Not one person has my equipment or anything like it, or my turnables tonearms cartridges or has done a real "experiment" that proves anything at all. Mostly I read that the guys that have tried these constructs have found it to be pleasant and to make them happy, sometimes after much fiddling and some expense. My turntables/tonearms are also pleasant and make me happy. Please leave me be on this subject. This is what I was saying above; there is room in the universe for both approaches, so I at least wish to move on. You and a few others cannot be happy it seems unless the rest of us acknowledge that the plinthless/armpodist way of doing things is genius. It's not; it's just another way of doing things that inevitably comes with its own set of compromises. (Of course, this is my fault for posting here again. Sorry about that.) I guess I'd rather sling solder than machine metals. |
Dear Halcro, I gotta love ya, but you wrote, "through my speakers/room/equipment interface I hear exactly the same spectrum of sound quality as through the headphones with an added air, transparency, depth, bass impact, instrument positioning and emotional content."
I submit that this is impossible. Both can be superb, but the two systems can never sound exactly alike.
I have been away for a while and I intend to stay quiet in future, but after reading the last few weeks of posts, it seems to me that the Copernicans not only want their view to be "acceptable' but also for the non-Copernicans to say "uncle". I have written many times that I am quite certain your respective systems can sound excellent, but please don't think that makes you "right" and the rest of us "wrong". In turn, I will continue to say that I don't think any of you are wrong, either. (Ct, if your tonearm did not move, it did not move. OK?)
If I were going to implement an outboard arm pod there would be certain ways that I would do it. As an illustration, I like the DaVinci approach, sans the gaudiness of that turntable. Note that the Da Vinci armpod, motor pod, and platter pod are all made exactly the same way, of the same materials, and use identical footers. Plus Da Vinci recommends that they all should sit on a specific surface atop a specific stand (available for a mere $40,000 extra).
Dear JC, You are being too generous to say that Henry or any of the rest of us have conducted an "experiment" in the true meaning of the word. |
Dear Henry, Sometimes a thing is "good enough". My LP hardware is in that category. My spare time is limited, and I would rather be listening to some good jazz than fiddling with an armpod. As it is, my amplifier project seems endless, and I am always thinking of ways to improve my pre-amp. Making those slate plinths took a lot out of me, I guess. In short, I will not be making any armpods or modifying any turntables to accept an armpod in the foreseeable future. |
Henry, What tt is that? It's impossible to be certain that the arm pod is indeed independent of the tt, from that angle of view. |
I see it now. Thx. That is one heckuva pod. Still would like to know the name of this table and who makes it, not that I am in the market. Does it really retail for $150K, as H implied? |
Thanks, Banquo, for going to the source. I won't understand the design unless or until I see a good engineering drawing of his bearing, nevertheless. I got nothing from his description, but he is to be credited for trying. In a sense, I agree with Raul, I hate to see us audophiles condemning a piece of gear for its price, per se. But I also agree with the others who look at this turntable and cannot see where is the $150,000-value. This is the designers fault for not using enough chrome and lucite doo-dads and for not including an elaborate stand to hold the whole thing up. These latter items tend to make us "believe". Look at that Clearaudio Statement, for example. Now THAT's good marketing. (The product makes me ill, however.)
The YouTube video is ridiculous. There are dozens of turntable/shelf combinations that can pass that test for well under $10,000. But it does not prove the tt is not "worth" $150K, either. |
Is that gold or polished brass? I tended to think it was the latter. Don't know the identity of the artist, but I am not curious, either. |
Dear Raul, All that you say about the current state of high level R&D in audio is probably true. On the other hand, modern designers have available methods for machining parts both for beauty and for function that were never dreamed of when those Technics engineers went to work on the SP10, for one example. Further, we now have transistors, ICs, resistors, capacitors, etc, that far outperform the 1970s vintage of the same items. It's kind of a trade-off between the good old days and now. And in the end, the person who is buying this turntable needs to be convinced that somewhere in there are some unique and transcendent qualities that make it worth the price. That too is the job of the designer/inventor. I would also reiterate that I already stated I do not hold with those who condemn things purely on the basis that they cost "too much". But, sorry, right now I just don't see $150,000 here. I will keep an open mind until I have a better understanding of the unique qualities of this piece, if it has any. If I decide to go to RMAF, I will look for it there.
That bit about the tonearm mount and the turntable/bearing resonating at different frequencies is possibly more true for separates than it is for turntables with integrated tonearm mounts, IMO. (But I don't want to flog that horse here any longer.) |
I agree. I would rather hope to find out more about how the bearing is constructed by talking to someone in the know, first hand. The bearing seems to be the crux of the justification for astronomical cost. Otherwise, the tt looks like it could fit into the TT Weights line-up quite nicely, as a representative belt drive and at TT Weights pricing. |
Halcro and DT, That part of the design (ratio of size of support pedestal to its upper functional part), reminded me very much of the Simon Yorke turntables. However, the maker of the Onedorf is telling us that his bearing is perfectly true. Therefore the platter does not wobble one iota in the course of its rotation. Therefore its rotation would have the effect to stabilize the structure, like a gyroscope. Pretty cool, eh? |
Or try to find some good reason not to be on board when it takes off from Lakehurst, New Jersey. Why did you go there, anyway, of all places? |
Brad and Henry, I have found that small size cans of mandarin orange slices in water make excellent footers for my Lenco in slate plinth. I use 3 cans, tiptoes on the bottom of each can and a spacer on the top of each can so that the turntable makes contact through the top of the can rather than its rigid elevated lip. In theory, the assymetric distribution of the orange slices in the water help the absorption of energy entering the can from below due to floor-borne vibrations and the dissipation of any tiny amount of energy that might enter via the tt motor, altho the slate takes care of most of that, IMO. Cost = $2 per can or less plus some tiptoes that were lying around.
Henry, "Rigidity" a part of your holy trinity of armpod design, is good but not an unalloyed virtue since rigidity assures transmission of vibrations up from the shelf into the tonearm. |
Dear Ecir (Brad, I think), Thanks for that URL but which feet on that page are you using? There are at least 6 or 7 different products shown. (This kind of troubles me because it makes me wonder whether the manufacturer has a real "philosophy" or does he just want to have something for everyone to buy, no matter what are the buyers preconceived notions.) For my Lenco, I needed rather tall feet, because I have an aftermarket bearing that sticks down well below the underside of the slate plinth, and tall feet are needed for proper clearance. Since I am allergic to spending on megabuck footers, interconnects, spkr cables, AC cords, discs, weights, etc, etc, I seized upon the idea of canned goods as footers.
Dear Raul, I think I understand what you are saying as regards your preference for lighter platters, which is that high mass objects might have trouble letting go of energy that is delivered into them, and heavy platters might therefore continue to accumulate vibrational energy that can leak into the LP and cartridge, rather than to dissipate it internally. This is a reasonable theoretical consideration, but what evidence do we have that it is operative in the world of turntable platters? Moreover, if the platter is made of layers of dissimilar materials, and/or a proper platter mat is employed, I believe the issue could be ameliorated. Please correct me if I have misstated your thesis. I am not a "big-platter" guy myself, as you know.
We can all agree without rancor that power supplies for turntable motors are a critical determinant of the performance, regardless of the drive system. I have demonstrated this for myself in my system many times.
Finally, I don't understand why it is necessary for your and Thuchan's interchange to be so caustic (not to mention the back and forth between you and Dertonearm). You are both good and sincere guys and this is all fun and games, as Thuchan likes to remind us. I've never heard an SME, but I have heard from others that it is either fantastic or dry and analytical sounding. |
Henry, Agreed. Dissimilar materials. Spikes only work as diodes if one takes care to place them over vibrational nodes in the shelf material. These can be identified by tapping the shelf whilst moving a stethoscope bell across it so as to find places where the tapping sound is least well transmitted, i.e., a node, a point where the shelf is not in motion. I have done this, and it's really quite obvious when you have found the sweet spot. Otherwise, spikes will move energy in both directions albeit with different efficiency depending upon direction. |
Dear Henry, I just stumbled upon this revival of your interesting thread. I think in your post of March 6 you have accomplished a well known rhetorical ploy; you've raised a "red herring". My argument (and Dover's) was never primarily about plane parallel mounting of tonearm with respect to the platter surface, although I would never argue that this is not important. My argument for a fixed relationship and a physical connection between the tonearm base and the turntable bearing assembly had mostly to do with preventing motion of one relative to the other in response to external or internal sources of vibrational energy. One wants the combined structure to dissipate mechanical energy as a unit. My metaphor about trying to cut a diamond resting in a rowboat whilst sitting in a second rowboat vs performing the same task while having the whole operation in one boat (easier, obviously) was meant to illustrate the point. That's the "bad thing" that I fear could come into play when a tonearm is mounted on an entirely separate support system and dissociated from the platter/bearing. Disparate vibrations of the platter vs the tonearm generate spurious signals from the cartridge.
I would also posit that the problem of "parallelism" (for want of a better single phrase) exists for both types of systems. A less than astute user of an outboard arm pod could screw up the parallel relationship between tonearm bearings and LP surface even moreso than could a poorly executed turntable design. As someone else with a lot of experience in tonearm design once remarked regarding azimuth adjustable tonearms, having the capacity to adjust azimuth endows one with the capacity to really mess up azimuth adjustment, as well as to get it right. |
OK. I read the first paragraph or two and then ran out of energy (vibrational and otherwise). Why can't you imagine that two wholly independent structures could react differently from one another to, lets say, a heavy footfall on one hand or the 1812 Overture blasting into your listening space, on the other? (I see that you don't believe that the energy put out by a loudspeaker can cause damaging mechanical feedback. This is your right, just as it would be your right to believe the earth is flat.) If you can't imagine that two structures mounted on your shelf might respond to energy coming into them by any of these and several other various routes in different ways (different resonance frequencies, longer or shorter time to dissipate the energy, etc, etc.), and if you cannot imagine that there is some advantage to having a single combined structure that responds in unison to extraneous disturbances, so as to minimize relative spurious motions of the cartridge vis the LP groove, then I cannot help you, but it is not I who is ignoring or not understanding the science. By the way also, you CANNOT stop all energy from entering into your turntable/tonearm. No one can. Unless you want to send your system into gravity- and friction-free outer space and cut rocket power thereafter. (Good luck setting VTF out there.) So, it's nice that you prefer a totally isolated system, we all would, but it ain't gonna happen on earth.
By the way, the PLINTH has nothing to do with this discussion. That is a different obsession of yours and the subject of a different thread.
You also wrote, "So now your a priori proposition (devoid of any facts or evidence) has been questioned
.you are left with the claim that the advantage of a plinth is that a separate tonearm base is likely to be adjusted out-of-level?" Did you really read my preceding post? That is exactly what I said I did NOT say. We've never discussed that issue before, so far as I can remember. It's pretty obvious that any design that gets the tonearm bearings and the platter surface plane parallel is OK, regardless of how it's done. This has nothing to do with our subject.
I think you want this thread to be read and contributed to only by those who swallow your line of thinking hook, line, and sinker, and who come here to kiss your butt. |
Raul, With the big Micro Seiki's, and since we are all about building new or modifying original products to suit our beliefs and desires, isn't is possible to get around their perceived problems with the armboard mount by using (i) an outboard armpod, or (ii) a modification of the original cantilevered design? Since those tables reportedly have many virtues (never heard one myself), wouldn't this be worth the effort?
Here is another bone for contention: It's fine to say that the "shelf" is the plinth when one is using an outboard armpod (regardless of whether the turntable itself is plinth-less), but so far as I can tell, no one is mechanically fastening the two entities to the shelf. Thus, there is nothing to prevent disparate energetic interactions between the turntable proper and the shelf, on one hand, and the armpod and shelf, on the other hand. As you know, Henry, a shelf will be put into oscillation, by energy put into it. Objects that just happen to be sitting on a node (an area of the shelf that is not moving) will be relatively immune to the problem of the shelf vibrating under it. (The location and number of such nodes will be related to the material of which the shelf is made, its density, its thickness, and thus its resonant frequency.) Other objects that happen to be at a point of maximum movement of the shelf as the wave of energy is absorbed, expended as heat, and dissipates, will move most. Therefore, it is quite likely that the arm pod and turntable will be differentially effected by resonance of the shelf. This will cause relative movement of the one vs the other. This will happen more or less regardless of the mass of the armpod and turntable, etc. This is the crux of my argument.
There are some very expensive turntables being made these days with separate arm pods. The Simon Yorke, da Vinci, TOTL Kuzma, and one or two others come to mind. It seems that those designs at least provide very similar mounts for the two separate structures, very high mass, identical materials, etc. Some or all of these also include the mounting shelf, which I think speaks to my point. Such construction could mitigate the problem. I am not arguing that it can't "work"; I am just pointing out the issue that needs to be considered. |
Henry, You misunderstand me. I really don't give a shit. I am not hyperventilating, and yes, your angry tirades (and one response of mine which was written in anger), in lieu of what could be an interesting back and forth discussion, and your total lack of introspection and self-doubt are indeed "comedic".
I do think there could be some merit in minimizing the plinth (but not eliminating it entirely) for direct-drive, and I do think that a separate arm pod might be a way to go once one has done that, but I would advocate some definitive linkage between arm pod and mini-plinth.
If you don't believe that your shelf can vibrate differentially according to location, take a stethoscope and move it around the surface of your shelf while you wiggle it or tap on it. You will find not only that you can hear the tapping through the stethoscope (not surprisingly) but also that the intensity of the sound will vary from one point to another on the shelf. Where the intensity is minimal, that is a node or close to a node.
Considering the greater scheme of things, I will quote Humphrey Bogart in "Casablanca", this issue does not amount to a "hill of beans". |
Dear Raul, What you write makes perfect sense. I note that most of the MS users have modified their tables to get to where they are happy with it. Along those lines, I would have thought that an outboard arm pod would at least defeat that very real issue you cite about mounting of the OEM arm boards. On top of that, I noticed that some guys use thick mats of various kinds, and other devices, to reduce platter ringing. Further, many use more modern motors, as even the real diehards agree that the MS motors are not so great. By the time one is finished, not much is as original. But I cannot criticize the result, because I never heard one.
One might say that we Lenco users do the same thing; many factory parts are typically discarded and replaced in a well tweaked Lenco L75, but we start with a $300-turntable that is fundamentally sound, not a $5000 (and up) one. |
