Apples and Oranges. The Townshend damping trough is a whole different thing from the bearing at the pivot of the WT tonearms. I think very highly of the Townshend idea, but it is a bit clumsy in its application. Nevertheless, the principle makes a lot of sense. You might say it's the only right way to dampen the energy developed at the headshell properly. As to the WT use of silicon damping at the other end of the tonearm, at the pivot, the damping per se may be a fine idea but in the case of the WT, the pivot is not otherwise fixed very tightly in space. It's a golf ball in a trough. That's my beef.
High mass vs Low Mass Turntables - Sound difference?
As I am recently back playing with analog gear after some 15 years away, I thought I would ask the long time experts here about the two major camps of record players -- high vs low mass-loaded-type tables...
For example, an equivalently priced VPI table (say a Classic, Aries or Prime) versus a Rega RP8/10 or equivalent Funk Firm table... the design philosophies are so different ... one built like a tank, the other like a lightweight sports car...
Just wondering if the folks here have had direct experience with such or similar tables, and what have been your experiences and sense of strengths and weaknesses of these two different types of tables.
For example, an equivalently priced VPI table (say a Classic, Aries or Prime) versus a Rega RP8/10 or equivalent Funk Firm table... the design philosophies are so different ... one built like a tank, the other like a lightweight sports car...
Just wondering if the folks here have had direct experience with such or similar tables, and what have been your experiences and sense of strengths and weaknesses of these two different types of tables.
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analogluvr My only beef with it is that it does not keep consistent azimuth across the record.It doesn't? How do you know this? If you're correct, it sounds like a seriously defective design or sample. Details, please. |
Instability of the azimuth setting is precisely what turned me against the WT tonearm. My long time friend had a WT Reference. The tonearm could be seen to "roll" from right to left, changing azimuth all across the surface of an LP. I like to think this design flaw has been corrected in more recent versions of WT, like in the Amadeus, but I have never operated an Amadeus. I do know it is much loved. But that's one of the first things one expects of a tonearm; hold the settings stable. It's like saying you have a great turntable, except it doesn't hold speed. |
LT tonearms still need to be set for azimuth. LT tonearms need to place the stylus tip exactly on the radius of the LP, from the edge to the center of the spindle, else they are always tracking at an angle, and off-center LPs offer the same set of problems for an LT tonearm as for a pivoted one. Then you've got the air pumps, leveling of the platter, etc, etc. No free lunch. But if that's your cup of tea.... Also, LT tonearms are problematic on light weight, suspended turntables. |
@lewm I concur to setting azimuth on LT and my HK Rabco(very heavy and unsuspended nearly 40lb deck pretty rare to find as well) does have azimuth adjustable. LT arms indeed problematic with suspended turntables and less-likely you can find one made or built that originally goes with linear arm. Most of LTs move the arm tube as soon as it tracks to the point of electrical contact to engage the tonearm motor that will move another notch of the arm tube close to the end of record thus LT always tracks at angle, but not as sharp as pivoted arm so the problems aren't same for pivoted vs. LT. |
Lew and harold, I remember that ET arms were popular on Oracle tables but I never understood why? I owned an Oracle for awhile and found it to be EXTREMELY sensitive to balance. Mine had a sort of counterweight balance under the platter but I still had problems, even with a conventional pivoted arm (SAEC). Maybe later versions of the table remedied that? |
Czarivey, You own one of the few LT tonearms that operate as you describe. I believe Mr Rabinow invented the idea of having a little motor move the tonearm in increments, when it makes contact with a tiny switch located back behind the pivot. Like you say, this assures that the Rabco tonearms (and the Goldmund TF tonearms which copy Rabcos) are swinging in tiny arcs across the surface of the LP, for good or ill. But most modern LT tonearms are either riding on an air bearing (with a rigid 90-degree connection between the arm wand and the air-borne carriage) or gliding downhill toward the center of the LP because of dishing of the LP surface, a la the Souther. |
There are few modern linear arms made with air bearing just like air-hockey.On the contrary there are many - Eminent Technology, Air Tangent, Cartridge Man, Bergmann, Kuzma, Walker, Zorin, Terminator just to name a few. I never had any kind of problems using Terminator T3Pro LT on my ORACLE DELPHI.The sound was very convincing, quite incredible to be honest for a BD suspended deck. The best I ever had heard hands down.It is not possible to balance an air bearing arm on the Oracle if it is properly set up, suspension is too soft. Been there. If you balance the arm to 0, i.e. floating, you can see the arm drifting either side of the centre of travel as the suspension shifts. This is clearly audible in a good system. |
My ORACLE`s suspension is not "too soft", it´s just works superb. I can make my suspension bouncing up and down (3.5 Hz) whilst playing a record with excellent sound quality. The early DELPHIs with soft suspension are superb performers IME. I never liked DELPHI IV with stiffer suspension. And with hard acrylic mat it sounded quite awful, to be honest. |
Avanti, On many counts, your analysis is not entirely correct. Without going through all the arguments, if you like belt-drive you want the pulley and the platter to be as similar in diameter as practical, and as close together, center to center, as practical. This reduces belt-creep and enhances transfer of motor torque to the platter. Also, why does having a small pulley driving a large diameter platter prolong motor and bearing life? The motor has to spin faster in inverse proportion to the ratio of the diameters of pulley and platter, which I would think would tend to shorten motor life. Ditto for the bearings, especially the motor bearings. Belt life; that's a toss-up. But just the fact of using a belt places side stress on both motor and turntable bearings. |
dover1,088 posts05-25-2017 5:37pmThere are few modern linear arms made with air bearing just like air-hockey.On the contrary there are many - Indeed you've named few. Now try to list ones that don't use air bearing and than compare two numbers and the number 'on the right' which is modern linear arms will be infinitesimally small. |
@lewm a smaller motor pulley driving a larger pulley (platter vs. sub platter) has many engineering advantages as can be computed in simple belt pulley - pulley drive system configurations. i performed some engineering calculations simulating a 1" motot pulley driving a 12" platter vs. driving a 4" sub-platter. Below are the findings: 1) Bearing force. The platter driven system has a bearing load force of 2.8 lbs. The sub-platter driven system has a bearing load force of 6.7 lbs. or 240% more load. More than twice the force on the bearing means increased wear, noise but more importantly increased drag on the speed of the platter. 2) Cyclic Variation (in belt tension). The platter driven turntable has a cyclic variation of 0.79 lbs. The sub-platter driven turntable has a cyclic variation of ~2.4 lbs, over (3) times as much as the platter drive. Because the motor and belt in the sub-platter system have to work harder to spin the platter, the tension on the "pull" side is much less than the tension on the "slack" side of the belt. This translates into constant pull / release tension cycling and stretching which will wear out the belt significantly faster than the relatively light belt stretching on the platter driven turntable. 3) Drive ratio. How many revolutions the motor pulley spins in relation to the speed of revolutions of the platter. The platter driven drive ratio is 0.083 while the sub-platter driven system drive ratio is .25, or 3X as much. What this means is that speed variations in the motor of the sub-platter will be magnified 3X as compared to speed variations in the sub-platter motor. In other words, a speed variation of 1% in platter driven system caused by the motor will equal a 3% speed variation in the sub-platter system, all else being equal. A platter driven system has 3X the speed stability of a sub-platter driven system. 4) Drag resistance. This is a simple lever arm calculation. The larger pulley (12" diameter pulley) compared to the sub-platter (4" diameter pulley) has a 3X greater resistance to drag forces. Drag forces in the form of tone arm drag (minimal but measurable) and bearing drag. Bearings are not frictionless. But because the bearing forces are 2.4X higher in a sub-platter system, it has more drag to overcome and 3X less capability to do so. In effect, the sub-platter system is 5.4X more sensitive to drag caused speed variation than the platter driven system. Summing up. The combination of much higher bearing load forces, belt tension variation, 3X more speed variation sensitivity and 5.4X more sensitivity to drag forces place the sub-platter system with a significant amount of physical and mechanical disadvantages when compared to a platter driven turntable. It's refreshing to see that the high end turntable manufacturers actually have some sound engineering and physics principals to back up their designs. |
I recently heard the Rega RP 8 and was very impressed. I actually think it is a better table than say the VPI prime and Classic. I believe the scout actually sounds just about as good as either of these tables. The problem with VPI is their arms. Unless you use a moving magnet or moving iron cartridge, you will run into tracking issues because there is no real anti-skate mechanism with their arms. Not good when you are running a low output moving coil cartridge that magnifies everything so much, you need an arm that will not fight the tracking of the cartridge/stylus. I think the founder of VPI does not really believe in anti-skate. Well, i guess if you use an aries with a 12 inch arm that probably helps a little. But if you do not have a 12 inch arm, you NEED antiskate. The Rega tracked much better than the prime or the classic and really digs into the grooves. Amazing table for the money. The only thing I do not like is it is too plug and play.I am not sure their cartridges are the best and I believe their arms are worthy of much better. |
Tzh21y, you and I are hearing the same thing. The Rega has this incredibly clean, detailed and fast sound. I never liked the VPI arms either and they are a pain to setup. Also the VPI drive system always has a bit of noise as you can hear the round belt riding in the crown of the pully unless they changed that I always thought that was a design difficency of that design. I will disagree with you on your last part, the new Rega Alpheta 2 is a remarkably good cartridge, it is way better than the 1rst gen Alphea. For the first time Rega is actually getting raves on their cartridges. The exact and bias do sound good for the money but lacked some of the midrange bloom of some of their competitors. The new Alpheta 2 and the new Anima cart are really quite special. Dave and Troy Audio Doctor NJ |
@geoffkait and @pryso made very good points i.e. corvette vs Lotus and that there are lots of variables as opposed to Low vs High Mass. Take into consideration a deck like the EMT 950 which has a very light platter but has a substantial chassis/plinth and a very heavy/powerful motor. I am personally intrigued by the Rega Naid which is ultra low mass - the reason being that I had once believed MASS = BASS. I understand that the Naid ain't lacking in the bass department. Likewise the DPS ain't heavy mass but when I heard it - due to the powerful motor and resistant bearing it produced sledgehammer bass. |
I would correct geoffkait on his claim that sorbothane needs to be constrained to work. I have been using it unconstrained for years with good results, on speakers, headphones cd players etc. However constraining, i.e. covering the surface which is not in contact with the equipment, improves its use a lot. You do not need aluminum sheets. I have worked with various clamping devices and found that very little force on the sorb worked best. In fact I simply use 4 layers of electrical tape and get great results and have ditched the metal clamps. |
Huh? What? I never said Sorbothane only sounds good contstrained. What I said was Sorbothane always sounds bad, no matter what. If you can find any place where Sorbothane sounds good you are a genius and I congratulate you. Trust me, there are much better sounding though similar looking materials when constructing constrained layer dampers. |
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I am sorry, but science just does not lie. Philosophies and strawman arguments of striking a pot with a piece of wood - saying things like the lighter design will store energy for less time - possibly - because if vibrates more quickly at dramatically(flying across the room or at least moving more) and since there is constant sources of vibration in a record player...that is not a good thing dispelling energy in a short amount of time means more dramatic vibration. Hey, if that vibration sound good...bingo! Strike an empty beer can and it will fly across the table. Strike a full beer can and it may move an inch. Which one vibrates more? Trick question because it is more complicated than that. Sustained vibration attenuation is in the implementation and composition of the materials.. Lighter things can vibrate less than heavier things. A heavy bell is made to vibrate, where a check of wood is not. There it is - the quality of sound is in the implementation. As is the same with pretty much anything in audio...Guess what...you can make a light turntable sound great and you can make a heavy turntable sound great. But science is science and *in general* the heavier/denser an object, the lower the fundamental frequencies of the object will be. Do you want a lighter plinth that vibrates at a higher frequency - or do you want a heavier plinth that vibrates at a lower frequency? Additionally, Acceleration ( movement/vibration ) = Mass x Force. If you have less force or less mass(of the moving parts), then Acceleration ( movement/vibration ) is reduced. In any case - *in general*...reducing the forces/movement inside a turntable will reduce acceleration and therefore vibration. This holds true to both light and heavy tables. But science says that imparting that force on a lighter plinth gives you more acceleration to the plinth because the same equation applies to the body being acted upon. It is easier to move a lighter thing and it takes less force to do so. So these philosophies I see in audiophile circles are really more ideas..."what if we did this?" - then proceed to make up reasons why it is better only half based on science. Then make a great sounding turntable regardless of the weight. The correlation and misapplication of principles gives me headaches. Unless you are using vibration to make something sound better( like a violin ), I do wish more people would focus on the absorption and damping of vibration. That is turning any produced mechanical energy produced by the turntable and from external sources into heat as fast as possible.
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I have owned a number of sprung and massive tables over the last fifty years, including a VPI Aries, AR, and Linn LP12 (contemporary, near the top of the line). Typically sprung tables tend to “sound livelier” is the characterization. I feel that is correct. Massive tables sound more… sorry, solid (as in solid bass). There are tables of both philosophies in most price categories and as you rise in price they converge on much better sound and less as to belonging to either camp (lively / solid). So, since there are so many tables and price ranges, observations can drive one crazy as to which is better or just different. especially since they are set up in your particular venue and they are susceptible to vibration from your system playing and environment.
Anyway, characterizations of “the sound” of a general disingenuous disappears with better and better implementations. |
Damping + Absorption or alternatively Damping + Efficient Dissipation. These are the Criteria that are keeping TT Design at a place of divergence. I have moved on from Mass and Absorption, and now am Wed to Lighter Weight and Efficient Dissipation. There are Lighter Weight and Mass Materials that are equally impressive in the Damping Measurements. There are Lighter Weight and Mass Materials that separate quite differently from how the dissipation measurements compare. It would seem a certain frequency of dissipation is what is selected by designers to as a means for their products to conform to a specific trait of a SQ or Coloration. |
"Acceleration ( movement/vibration ) = Mass x Force. If you have less force or less mass(of the moving parts), then Acceleration ( movement/vibration ) is reduced." I don’t know what force, mass, or acceleration you are addressing, but your equation is wrong. Newton’s First Law of Motion says F=ma, Force = Mass X Acceleration. Then, Acceleration is equal to the Force divided by the mass. Therefore if you have less force (or torque in this case, because you are talking about an angular Force), you get less acceleration, which actually makes sense. But if you have less mass to be pushed around by a force, then acceleration due to that force increases. As a consequence, your next sentence, "In any case - *in general*...reducing the forces/movement inside a turntable will reduce acceleration and therefore vibration." Is also incorrect, even if I am not sure how you are equating acceleration with vibration. |
It's got to be a question of balancing all of the various unwanted resonances and speed inconsistencies. With this in mind I'd favour low mass designs although I have heard some fabulous high mass designs too. It would seem that Harley Lovegrove of Pearl Acoustics also feels the same way. I've already heard the excellent sounding Rega P8 and if the P10 really is that much better as he claims...
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@lewm , Thank you. I was getting cross eyed. @bdlitzer , you are right about issue. Isolating the turntable from vibration and turning into heat as fast as possible is the right approach to turntable design. All of the best turntable sound exactly like nothing. They do not add or subtract anything and they block any extraneous vibration from getting to the cartridge either through the platter or through the tonearm. The turntable and tonearm also have to totally dissipate the vibration coming from the stylus. If you put you ear to the cartridge while playing a record you should here nothing. |