Mijostyn, no matter what you may “think” and no matter what is your opinion, “velocity” and “speed” are not synonymous. We, all of us, may use them as such, but when we do so we are being sloppy, in a convenient sort of way. Why are we even arguing about this? It has nothing much to do with anything substantial. the fact is that if you are going to talk about what is going on with a stylus in a groove, then it does become important to distinguish between velocity and speed. The reason the speed is changing up and down as the stylus negotiates the groove is because the groove necessitates rapid changes in direction. Changes in direction are what distinguishes velocity from speed. |
Dear Mijo, Please don't put words in my mouth. "Velocity" is a vector quantity, meaning it formally has both magnitude and direction, although we usually omit to specify direction. "Speed" is a scalar quantity, meaning it describes a magnitude only. When the groove is especially tortuous, the angular distance on the arc traveled by the stylus tip with respect to the spindle or the center of the LP is less than the actual distance the stylus travels to get between any two of those points on the arc, because the stylus is wiggling back and forth in order to follow the path of the groove. What I was saying is that each "wiggle" forces a change in velocity, if you were sitting on the stylus tip. (I think it would be like riding "The Whip" in an old time amusement park.) A change in velocity is by definition an "acceleration". Any time a mass (the stylus tip) is accelerated, a Force is required. Since the vector direction of that tiny force is generally in the same direction as the force required to overcome friction, I am suggesting that the two Forces add, which results in one reason why the skating force is never constant. (The other reasons have to do with the ever changing angle by which a line drawn through the stylus/cantilever to the pivot is not tangent to the groove.) Like I said before, this is only my own hypothesis. But it survived my own close examination. I am open to criticism.
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No. What I am referring to is the fact that velocity is not a parameter to be found in the equation for the force of friction. And friction is the basis for the skating force. All other things being equal, friction is the same at 33 as it is at 45rpm. I take your minor point that groove tortuosity does seem to contribute to the skating force. Or what we observe as a skating force. I think that is because the tortuosity of the groove causes tiny accelerations and decelerations, i.e., changes in velocity of the stylus. Every time you have a change in velocity you have an acceleration. Every acceleration generates a force (F=ma). So my hypothesis is that the contribution of groove tortuosity to the skating force is due to these accelerations, which are not really due to friction. In that sense, Ralph is correct. |
Ralph is a mentor to me so I hate to correct him and I do so with trepidation, but stylus velocity is not a determinant of skating force. Just saying. |
Jay, Yeah, but with a good DD, there is a brake that stops the platter on a dime, and it takes seconds to get back up to speed. So stopping the rotation in order to change or turn over the LP is not going to cause any extra delay.
Along the lines of Atma-sphere's theme, besides the SP10R or the SL1200G, very few DD aficionados these days use the OEM plinths that were supplied along with the typical DD turntable in the vintage days. I personally favor high mass and constrained layer damping, along with an energy absorbent shelf that could do its work by any of several modalities. Heck, I wouldn't even look down on a spring-supported shelf if done properly. MC seems to have done that. Nor do most use the thick rubber mats that also were normal fare in days of yore. Those definitely killed the sound. (See also the many posts by Chakster and others regarding preferable mats.)
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Mijo, What we disagree on is the idea that a typical spring-suspended turntable is the sine qua non of turntable isolation. I fully agree that isolation from environmental energy is important, and we agree on the why of it. But I don't think the SOTA as prototype is the best way to go about isolating a turntable from the environment. And I have stated the reason for my opinion several times: With all such systems, and the SOTA is not much different from the now ancient and much loved AR turntable of yore and all its descendants (albeit the SOTA is far more advanced), the designer has a choice. Either the motor is suspended along with the tonearm and bearing/platter, or it is mounted on solid footing, so it does not couple energy into the working elements. If the motor is suspended, then a major source of noise (and here I am talking about mechanical energy, not EMI) is coupled into the platter. Belt drive motors must operate at higher rotational speeds so as to maintain platter speed, compared to any dd motor, and what's more there will be a side force on both the platter and the motor pulley which eventually needs to extraneous noise due to the long term effects of friction, so I think that is why most designers of spring-suspended turntables adopt the other option, having the motor on solid ground, so to speak. But when the motor is mechanically separated from the driven elements, there will be motion of one relative to the other. If the belt is at all compliant, then there will be speed inconstancy owing to the stretching and relaxing of the belt as vibrational energy is absorbed. You like to talk about the 80s and 90s, when "everyone" figured out that belt-drive turntables were superior to direct-drive, but I would posit that what happened in those decades, besides the near total demise of vinyl, was the result of a propaganda barrage from the industry, not excluding the magazines. It was and is just so much easier to build a low end belt-drive turntable that everyone was and still is doing it. I was there, and I was swept up in it for a number of years, just as you were. Now some of the modern and expensive belt-drives do the suspension right, including the Dohmann Helix. I think that's a great turntable but I would rather not afford it. I would further point out that there are sophisticated methods by which to isolate a non-suspended DD turntable that in my opinion can have an effect at least equal to springs but without the negatives. So to be clear, by not liking spring-suspended belt-drives, I would not want to be seen to believe that isolation is trivial.
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I have mentioned this before: I had a pure copper made for me by a machinist, for my L07D. It weighs about 6 lbs, which is not a stretch from the stock stainless steel mat that comes with the L07D and weighs about 5.5 lbs. With a copper mat on an SP10 Mk2, I cannot rule out that at least some of the perceived benefit may derive from the enhanced shielding effect of copper. Just a hunch; no data except listening to my long gone Mk2.
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Just stop repeating the "oscillating magnetic device" meme, please, and the rest of your thesis would be less indigestible. You seem to think that the engineers who designed these devices were idiots unaware of EMI and the use of shielding materials. First of all or maybe last of all, a motor is not "oscillating" in the formal sense of the word.
I could say how can "they" use an compliant belt to drive a platter with an outboard motor and then mount the platter and tonearm on a sprung subassembly, whilst mounting the motor on a solid unsuspended support? Isn't that a recipe for speed instability? But I won't say that. |
Mk3 then Mk2 was not the best of the rest in my system to my ears. |
Mijo, I don’t know which of my posts you’re referencing but my last post was just to remind us why sometimes high effective mass is necessary and that low compliance with high mass is in my opinion not the prime cause of record wear so long as VTF is comparable to that of a typical higher compliance cartridge, eg, 2g or less. I don’t think you’d disagree. I want no part of arguing about suspension vs no suspension. There are too many variables. |
May I interject here that if you want to use a low compliance LOMC, and there are many fine sounding examples, then a tonearm with high effective mass is not an evil; it is a necessity both for best SQ and preservation of the LP. Furthermore, VTF and stylus shape are more determinants of LP wear than is the low compliance/high effective mass class of playback equipment, although I too prefer the opposite in general based on listening.
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No. There is no validity to the notion that the TP sounds muted compared to the FR64S. In fact, the idea is ridiculous without regarding the particular cartridge. |
I don’t think resistance, pure and simple, is the main possible issue with physical connections in the signal path. For one thing because each physical connection also has capacitance and/or inductance. For another, because very often the first gain device, tube or transistor, in a phono stage will be preceded by a series resistance in the 20 to 200 ohm range, to prevent oscillation. Such a resistance would swamp out any resistance of the preceding wiring system. Fairly high resistance ICs (Magnan, etc) were once in vogue, too. Yet I am agreeing that physical connections should be eliminated whenever possible and practical. |
Chakster, Hasn't your journey revealed to you that there are many, many excellent cartridges and that the differences among the many very good sounding cartridges are in terms of nuances that may or may not appeal to any particular listener. That is what I have come to believe; there certainly is no one single Holy Grail of cartridges. The existence of so many very excellent cartridges makes it all the more obvious when you come upon a cartridge that is just plain ordinary or "bad". Those can be readily eliminated from the play list. I also agree that matching of tonearm to cartridge can really make a difference. I could only have come to appreciate that by listening to many different tonearms with many different cartridges, and swapping cartridges among them. In particular, low compliance LOMC cartridges really need high effective mass to sound best. I find high compliance cartridges to be less fussy, in general.
For a few decades, the TP was my only tonearm. Then when I started playing with several different turntables, I began to acquire and to listen to other tonearms. I bought the Reed, which borrows heavily from the TP, and I bought several tonearms with interchangeable headshells only reluctantly, because I was steeped in the propaganda against headshells that was in the air in the late 80s and 90s. Like you, I am now addicted to having several cartridges pre-mounted on several different headshells, so i can swap from one tt/tonearm to another with minimal fuss. Doing that is a very educational experience. With a fine quality headshell, I absolutely hear no degradation associated with the extra contacts in the signal path, so long as I am using a high output MM or MI cartridge. With an LOMC, I cannot swear that it doesn't make a difference, but I have stopped worrying about it. My Koetsu sounds its best in my FR64S, regardless of the fact that I must use a removable headshell with that set-up. Also, rigidity of the connection between tonearm and headshell matters much less with high compliance cartridges, because those don't put much energy back into the headshell/arm wand. With low compliance LOMC cartridges, there is a case to be made, I guess.
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Not bitter at all. Just concerned to get the facts straight. What I am trying to point out to you, Mijo, is that you critiqued the design of the FR64S and fx tonearms without really being familiar with the design. The gurus who talked us all out of the idea of a removable headshell back in the 90s were and usually still are fixated on structural rigidity, not moving mass. You might make a case for greater structural rigidity of a fixed headshell, but please, don’t tell me that little knurled knob that tightens the headshell into place or that the ceramic socket that bears the contact pins is adding more than a gram or two in terms of effective mass. If you are so obsessed with that, then the only tonearm for you is an Infinity Black Widow, or the like. Also, one’s choice of cartridge and the screws that hold it in place and the headshell choice itself could have as much of an effect or more usually a greater effect on effective mass than does the added weight of the joint between tonearm wand and headshell. Your argument against removable headshells based on added mass of the joint structure is ridiculous; the arguments citing possible loss of rigidity and the necessary introduction of an additional physical contact in the signal path have more merit. Which tonearm do you think has lower vertical effective mass, any Dynavector, all of which have removable headshells, or a Reed tonearm with a nonremovable headshell where the arm wand is made from Cocobolo? (I am not saying the Reed cannot be superior to a Dynavector, but it won’t be so on the basis of minimizing effective mass. I am the happy owner of a 10.5-inch Reed 2A.) The distribution of the mass of a tonearm/cartridge, from the front end of the cartridge to the rear end of the spindle that holds the CW, defines its effective mass. That’s all been accounted for in the final figure. I am sure you know this. So if there is a gram or two extra mass in the joint, the calculation a priori has taken that into account. You speak as though the mass of the headshell joint is added in post facto.
I am not sure what you are saying about the effects of structure on VTF, but if the center of mass of the CW is in the same plane as the surface of the LP, that will minimize changes in VTF due to record warps. What I am saying is that the FR64S does place the center of mass of the CW in the plane of the surface of the LP. What’s more, the CW is decoupled from the pivot. That reduces the effect of the CW on the inertia of the tonearm. Moreover, the stub that holds the CW on the FR64S is displaced at an angle to the pivot, such that a straight line through its center of mass is parallel to the long axis of the headshell and cartridge. Further, the FR64S has a side weight to provide for lateral balance.
"Heavy tonearms and stiff cartridges increase record wear and distortion during playback as the increased inertia causes the cantilever to move instead of the tonearm." The cantilever is supposed to move; that’s how an audio signal is generated.
I know all about your fondness for SOTA turntables. That’s fine. I hope you recall my mentioning that my Star Sapphire Series III with vacuum clamping was the most speed unstable turntable I have ever owned. I did not appreciate how obvious that problem should have been, until I sold it on in favor of a Notts Hyperspace and added a Walker Audio Motor Controller. That’s why I urge SOTA-philes to go for the Eclipse upgrade.Finally, I use various forms of shock absorbing materials under each of my five turntables; I do not use springs or a formal sprung suspension, but I never said that absorbing floor-borne vibrations is a bad idea. (Please don’t come back at me with airborne vibrations; I know about those too.)
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Mijostyn, I think you are a nice guy, and I enjoy sparring with you, but what does rankle me is your consistent tendency to draw scientific-ish relationships between or among disparate factoids that are very often not at all related as cause-effect or at least there is no proof of a cause-effect relationship except circumstances. Further, you nearly always fail to label your dissertations as "opinion". You’re certainly not the only one who does this, but you write with such certainty that it might actually perpetuate some of your erroneous beliefs among newbies. Putting aside our complete disagreement when it comes to suspended, belt-drive turntables (I generally don’t like them except for the Dohmann) vs unsuspended direct-drive turntables (I like some of the best ones), your polemic on tonearms above is full of holes. The only thing you say with which I would have to agree is that use of a removable headshell does inevitably require an extra set of physical contacts in the signal path. I was just as taken in by this teaching against removable headshells, that was foisted upon us audiophiles back in the 90s, that I avoided using tonearms with removable headshells for about 20 years, until 5-6 years ago.
You wrote, "Removable head shells are a terrible thing to strap a tonearm and cartridge with. Not only do they add unnecessary contacts but they add mass right where you do not want it forcing you add more mass at the other end of the arm increasing the arm’s moment of inertia ruining it’s ability to follow record undulations." What "mass" are you talking about? The mass of the connector, which cannot add more than a gram or two to effective mass? Even tonearms with fixed headshells must have a headshell of some sort, which always adds to effective mass per se. Actually, separatable headshells make a tonearm more adaptable to cartridges with various levels of compliance. For one example, the FR64S is a tonearm with high effective mass, especially when you use the FR headshell that comes with it. There are a few different ones made by FR, but they are all pretty heavy, weighing 20g and more (and many say they sound bad, but I wouldn’t know). But one can choose to use a much lighter headshell, such as any good carbon fiber type that weigh about 10g typically, or any of the light aluminum headshells made over the years by SME, AT, Denon and others that weigh much less than 10g. So for the putative disadvantage of those extra physical contacts, one gains tremendous flexibility. Now, can you adapt an FR64S, in terms of achieving an acceptable calculated resonant frequency, to some of the MM cartridges from the early days with VERY high compliance, e.g. an ADC XLM? Probably not. But you can adapt an FR64S to nearly any modern medium compliance LOMC, if resonant frequency is your holy grail. Whether or not you can "hear" those headshell contacts in the signal path is a question I would leave to each end user to decide. I advise a touch of a good contact enhancer.
You also wrote, "They are static balance arm thus the VTF changes with elevation and the bearings are high above the record surface increasing warp wow." Wrong and wrong. I think the FR64fx is built just like an FR64S, only with lighter materials, but for sure the FR64S is a dynamic balance tonearm, not a static balance type. Moreover, the FR64S has a decoupled counterweight that hangs down into the plane of the LP surface, not "high above" it. It is a very modern design in that regard. I remember Herb Papier telling me he thought it was a big improvement, when he decided to re-engineer the Triplanar so to decouple the CW. Some guys don’t like the dynamic balance method for adjusting VTF; I just recently read that at least one FR64S aficionado ignores the dynamic balance feature and prefers static balance. Still others prefer dialing in some of the VTF by dynamic and the remainder by moving the CW. Using dynamic balance does permit one to get the CW as close as possible to the pivot, thereby minimizing its effect on net effective mass.
Let’s just keep our facts straight.
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Yes, if you insist upon using a "crappy" rack, the SOTA suspension will help. And if you have a lot of warped LPs, vacuum clamp or peripheral ring will help. Also, if you are testing nuclear warheads in your listening room.
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