After reading this, I was compelled to put my table on the work bench and study my rb-300. I noticed that the nuts on the end of the vertical bearings do not move with the arm. This supports your extrordinary theory. There would be no movement in the vertical plane of this extra weight.
Then there is the damping factor of the bearings, and/or the area at them. This to me also makes perfect sense.
As if I'm not intregued enough contemplating the origin live mod, now this.
I haven't tried any of these, yet.
These questions burn in my quest for analog reproduction; How much of this tweek is attributed to the damping or manipulation of resonences at the bearing point, and how much is attributed to resistance of movement of the horizontal plane?
As far as the resistance to movement in the plane, it would seem to me that resistance to movement in both planes would be as desirable, up to the point that the cantileler would remain centered. Of coarse, while movement to the contrary would be undesirable, the resistance to movement which allows the transducer to transfer/produce the signal is critical, it would seem to me that resistance in the vertical plane would be desirable as well. It seems to me also that records seem to want to jog the cantilevel horizontally more so, or as much, as vertically, as record clamps hold the record relatively flat, and nothing can be done about records being off-center. It would seem to me in theory that benifits would be had vertically as well, if not more so.
As for adding weight for resonence control, I can't help but notice that all of the most recent improvements to the top tonearms have been in making them heavier. The emergence of the rpm, the subsequent improvement of the graham (1.5 to 2), then the added improvement by making the bearing mount more massive, (2.2).
Compared to these arms, it seems that the rega is behind in weight, and it seems that where the weight is added is important, both for resonence and resistance.
Please keep these tweeks and knowledge coming. They are HIGHLY enjoyable. It would seem the cutting edge is right here on a-gon. |
I just had a scary thought-might want to put some of that tweaky brain-power to it, or at least calm my fears if you already know;
What of the possibility of premature cantilever wear or damage? I understand that underdamped arms or the wrong arms can cause this. (I'm starting to become a little weary of trying this with my clavis d.c., and actually, I'm starting to wonder about it evan with the arm now in it's present state, as it seems really underdamped in feel). Also, do you think that you might achieve evan higher results by adding some damping to your arm, in addition to what you have done? |
Zaikesman, the damping I was refering to is fluid damping and besides sound its effect on the cartridge is this; when the arm is put into motion, lets say to the left, the weight of the arm resist the motion, and then goes into motion to the left, pulled by the cantilever. when the cantilever then goes back to the right, the arm is still going left, and so the inertia arm of the puts additional stress on the cantilever.
How much stress is put on the cantilever is affected by how heavy the arm is. (actually not the weight, but the inertia, which is affected by weight).The higher the complience, the more the cantilever flexes to a given amount of weight, and if the cantilever can flex enough, and the arm is heavy enough, the arm can be put in motion.
The real idea is to keep the cantilever centered, not having to much resistance to movement so the arm follows the cantilever, but enough resistance to keep it from overshooting.To achieve this, a fluid of a certain viscosity is used, the viscosity permits slow movement with little resistance while faster movement is resisted. So you can see that the tuning of the viscosity, and amount, could achieve this.
Here's where it gets complicated-damping with fluid can have similar effects to adding weight, as the fluid restricts movement. Fluid can have positive effects on sound. How much is attributed to keeping the coils centered or the restriction of movement, or the adding of the solidity and resistance to vibrations is one question in my head. the other is that as weight is added, and fluid is not, this makes the arm more prone to going in motion.
Fluid can have negative effects as well. Besides the cantilever to be less centered by not having it tuned properly, or causing more stress than intended, to much damping kills the sound quality. In my experience, Adding damping cleans up the sound and widens the stages, and tightens aand focuses the bass. After a certian point, then the sound starts to get dulled in the high end, then becomes veiled and then more diffused past the point it was before it was added. There have been some instances where adding any at all caused this.
So there is the object of my curiousity, one or two of them, among others.
The damping you are refering to, Zaikesman, is damping the armtube for ringing, and it is always a good idea. I have always had good results, no matter how good or bad the arm, no matter how good the match of arm and cartidge. One of my favorites-a drinking straw, of slightly smaller diameter than the inside of the armtube, and stuff the space between the straw and the inside of the armtube. This provides a pretty good surface/dialectric for the wire as well. (seems better then having it smushed against the armtube). I want to try cat hair, but my doner cat moved on. My theory is that cats seem to absorbe sound,and they are always sneeking up on stuff. In the wild, they have to be sound absorbant, so there may be something evolutionary to that.
Twl, fifty bucks, that would be a bargain. Seems like a hard way to make money, as I don't see much profit there. I think a lot of people would be into it though. |
We have two ideals here, maybe three. As far as tracking goes, the arm should have low enough a moment of inertia to follow the cantilever wherever it wants to go. The stiffer the suspension, the more the arm will follow. If the arm is sufficiantly heavy, or the suspention has enough give, then the arm will stay put as the cantilever follows the groove. This is not ideal. But the arm should be of sufficiant resistance to provide the cartridge a good base for transmitting this information. The frequency of the movement of the cantilever should be faster than the movement of the groove but slower than the frequencies in the groove. This is naturally where the relationship between mass and complience comes in, the stiffer the cartridge, the more mass is desireable, but the mass should not be too high as to allow/cause the cantilever to deflect.
Throw fluid damping in and then we have a relationship between complience/mass/and resistance of the fluid, and changing one changes the other. Fluid is desired where the arm is to light to be ideal. Fluid is nessesary where the arm is heavy enough to cause the arm to 'wag' at a frequency enough to cause to much more stress at the cantilever caused by the wagging itself, if it is more than the suspension can handle. I understand linear trackers had a tendancy for this. (linear trackers have a reputation for bigger soundstages, and I am starting to see this as my eyes are being opened).
The one ideal I am speaking of is the centering of the coils. The ability of the arm to track the groove without overshoot caused by the mass of the arm. Fluid damping has traditionally been effective in this ideal. The other ideal is the mass of the arm being ideal for the control and or transmission of frequencies in the audioband, maybe more. I think that there is definitely something to this adding of mass in the horizontal plane that perhaps the makers of the best tonearms are missing right now. All of the evidence and information I have learned on this thread seems to support this.
This leads me to the question of fluid damping. One of the main reasons fluid damping has been employed is for the benifits of sound quality, caused by the controlling of frequencies by the behavior of the arm. I suspect that perhaps, some of these benifits may be caused because these arms may be deficiant in mass in certain areas, and I am questioning that if the arm/cartidge interface is ideal, and the ill effects are within the ability of the suspention, if fluid damping is evan desired. On the other hand I wonder if it would then become nessesary or more desired as a result of the added mass of the arm, as the complience/mass interface is now being severely shifted.
Rega arms have traditionally not needed or used fluid damping because the design of the origional arm was such that the arm provided good damping of unwanted frequencies while at the same time providing low mass, something that the rb-300 did/does exceeding well considering. But now as we tweek the arm closer to the ideal, and closer to better compatibility with these stiffer cartridges, we are getting away from the origional design. This leads me in the direction of thinking that now we may want damping on a rega.
But then again, these cartridges may be stiff enough that we may be getting past damping altogether. Fluid damping, while having some simalarities to mass is also different. What is happening at that critical place at the cartridge suspention and the effects of mass, damping, and complience, is what I am thinking of and wondering about. |
It took me a long time to understand as well. Now I'm grappelling with mass and it's relationship with damping. If you are like me, you think about this stuff all the time, and things come to you, (obviously, look at whats come back at us).
This part I think you might be missing- you mention that all (most) your records are not off center. While there are quite a few that are obviously off center, what we are talking about here within the cantilever/coils is microscopic. All records are off center, evan if just a fraction of a groove width, they aren't manufactured to the kind of tolerences we are striving for. If you dismiss this, then you shoot for the arm staying put at the cartridge. Really, what we want (in theory) is the arm to stay put directly over the cantilever. The key to this, with fluid damping, as stated by Z above, is the viscosity. Control the resistance selectively at selective speeds (traditionally, the speed being the frequency of the warp/wow). To see it, you definitely need to get in and look at the cantilever at the cartridge to see how much it is moving in relation to the cartridge. to measure it, you definetly need test records and the like. ( I don't have these resources, maybe you do).
There is more to controlling frequencies then just keeping the coils centered, though. There are, I believe and suspect, differences and simularities between fluid damping and mass. We are not done with this yet.
Last night, I put my immedia back on to test some of this. I drained some fluid out until the arm could tilt easily to one side but come back without overshoot. Then I weighed some pennies, came up with 5 pennies on each side to be about 12 grams with electrical tape, and slung them out with a paper clip. They are about 1.75" out on each side, just below the record height, slung out at the same angle as the cartridge, and just taped on the top with a piece of electrical tape, over the center of the bearing, and they swivel front to back because of the tape. archaic, but they increase the horizontal mass considerably with minimum effect on any other parameter.
What I thought I heard was a wider soundfeild with more separation between intruments. But the induvidual instruments seemed more truncated, less air and detail around them. The high end seemed more recessed with a loss in detail. I didn't adjust damping at all between the two. I did notice more movement of the cantilever, at least I thought I did. Sounded similar to adding to much damping, and of coarse this experiment is extreme, I didn't play with it any further.
One resource I don't have lately is too much time. I am currantly getting more enjoyment in the tweak factor by hearing your results.
The immedia has damping, and it is easy to control and adjust/change, but it is also much heavier than the rega, I plan on starting another thread if you don't to see if anyone has tried fluid damping with the rega, and if any is readily available.
This is a new tonearm you are designing, isn't it? You are changing the parameters of the design. Seems to me you are somewhere roughly as far from the rb-series as the ol 750 is. |
Keep in mind I am still trying to grasp a lot of this myself. I'm still wondering about the benifits/consequences of the differences/simularities. Zaikeman makes some really good points in that last post. Keep in mind here that the most commonly used fluid for damping, silicone, is newtonian, that is, it resist faster movements disproportionally to slower movements. Ideally, slow movements get no resistance, fast movements get great resistance.
Ideally, we tune this to follow that slow moving warp or eccentricy with no resistance, but resist movement faster than that.
Now picture a high complience cartridge on a heavy arm. The arm stays put, the cantilever follows the record.
Now picture a low complience cart on a really lightweight arm. The arm can follow it anywhere, but it is not a good enough 'base', if you will, to allow the cart to do its job. potentailly, the cartridge just throws it around, and it can't transmit the information.
Now, if the arm has some resistance, and the cantilever flexes, but the cantilever also is stiff enough to pull the arm, the arm goes in motion after the initial deflection to follow the cantilever. As the arm chases the cantilever, and the cantilever then is pushed the opposite way, the arm and the cantilever are both moving in opposite directions, and we get movment in the cantilever that is greater than the initial deflection. In this way, we get cantilever deflection that is greater than if the arm was not allowed to move at all.
In the above post, the statement that fluid resist movement constantly as opposed to mass resisting movement initially is a good explaination of how we use fluid to tame these unwanted cantilever deflections. But that is just one reason for fluid.
Fluid is also used to tame the arm of movement that does not allow the arm to transmit information, movement or vibrations that would allow information to be lost at the cantilever, (that is why townsend put the trough at the headshell, but I believe that it might have been a failure).
In my experiment with the immedia and the pennies, it is highly faulted, for those reasons you mentioned and others. the weights were literally just flopping front to back, and this would most problably cause some bad stuff. The purpose was to try to demonstrate to myself the possibility of substituting mass for damping fluid, as well as add mass to the horizontal plane. If in fact I did hear what I thought I was hearing, that is a wider feild and better separation between instrument, despite the degragations, that is something. I might not be able to go too far with the immedia though as it is already a heavy arm. The added mass may be too much. Also, what I was hearing might be side effects of the degragation.
Zaikesman, please ring in with some of the arms you used with fluid damping, I can see some good info here that may help us, as you seem to have a pretty good handle on this damping of fluid.
I'm going to follow up on some of that stuff and see if I can see what's happening. For now, I contend the following possibilities; Mass is highly desireable, and better than fluid for the taming of unwanted frequencies, (notice that arms have gotten a lot heavier), and that mass might be better placed than the current understanding of it's use, or that it may have more use than one. (or my understanding needs to catch up). |
The effect of the cantilever deflection in the reverse is a real thing. I've read about it and observed it. When you get your fluid damping devise (where are you getting it, by the way, so we may obtain our own), you may be able to observe it as well. I am blessed with near sightedness, and if I may pause to brag, I can count the seven strands or litz wire in cardas. To make it easier to observe, I get my mag-light and look head on at the cantilever, observing its revative movement with the cartridge. Then also I sometimes find a spot in the background and observe both the movement of the cartridge and the cantilever as it traverses the record. It is much easier to see with a record that is more off-center than usual, but it is rare that I find a record that I can't observe as being off-center. I have, and do, observe less movement of the cantilever when I damp the arm.
I'm going to jump around- first, yes the last sentence is speculation, I'll explain why later,
I am seeing two separete reasons/uses for damping fluid.
The one reason, is the centering of the cantilever in the coils. The other is the taming of unwanted frequencies.
On the first point on fluid, I am suggesting that the cartridge is a more accurate transducer with its cantilever centered in the coils.
On the second, There is both the issue of the speed at which the cantilever moves (which translates to unwanted bass information, the movement of the cantilever transmitting a bass frequency, which is the 'bell curve' stated above) and the control of the other frequencies higher in the audioband, the resonences.
Now I bounce again. You are correct in your statement of the tonearm being of mass according to the complience, as one reason tonearms are heavier than they used to be, and mass having other purposes. The current thinking in design is to keep the moment of inertia as low as possible in all planes, and at the same time, add as much mass as possible while keeping the moment of inertia low. Tonearm makers are also adding mass at their bases (no doubt allowable by better tables). This can be likened to the effects of a heavy platter being a better sink for resonences, as opposed to just better speed control. Or a heavy suspensionless table as opposed to one that seeks only to isolate.
The other trend, although not new, is the use of new lightweight materiels. The reason for this is not simply to make the arm lighter, but to make the arm stiffer by using more of these stiffer materiels. The stiffer the arm is, the more energy is channeled to these massive energy aborbing bases, and the more solid the headshell is at the cartridge as a result of all this.
Now I bounce back to the meat of our discussion. If we explore the use of damping for the second reasons I stated above, and we explore what is happening at the cantilever as far as movement (I like the bell curve analogy) we may be able to get better results by substituting mass for the reasons we use fluid in that area. The evidence I use to support this is that 1) arms have been getting a lot heavier, and that they seem to be attempting to put it where the moment of inertia would be lowest, 2) The graham arm has its weights slung out at an angle for stability and proper tracking of the cartridge offset angle, and may be enjoying the effects of greater horizontal mass as a side effect, 3) the reputation of linear trackers to have good soundstaging qualities, as they have a disproportionate horizontal mass to their vertical mass, perhaps an overlooked side effect in their quest for accurate transcription.
All of these arms use fluid, however, and in the case on the linear trackers, before it was made available on the E.T., the heavier armtube had a reputation for snapping cantilevers, for the first reason I stated above for the use of fluid. The wheaton also uses fluid, (a real heavywieght), slung out in what seems effective for tracking more than transferring resonences, and of coarse the immedia and graham both depend on it for proper operation.
Further evidence I suggest, and this is perhaps the most compelling, is that the rb-type arms are the lightest in this class, and that they have all benifitted from adding more weight from aftermarket counterweights, And in the deliberate attempt to add weight only in the horizontal plane, seems to have shown results disproportionate to simply adding more weight, and was added in what was stated in the beginning of the thread as perhaps an oversight to why the graham works so well. (the rega does not need counterwights for lateral stability the way the graham does).
I would correlate that fluid on a rega is a rarity and that it is also a lightweight.
So my thoughts now are, do we need to emply fluid on the rega to explore this to a higher limit, and also, if we choose to use more mass, if we would be better off not using fluid for certain applications. There may be trade offs as to how much we allow the cantilever to move in relation to the cartridge, wheather or not the cartridge/arm would work better being in a static position over the record, and reap the benifits of stability, at the expence of letting the cantilever out of center,(or evan if we could get dangerously close to causing damage).
What is particularly fascinating to me is that I have never heard of adding weight for the purpose of modifying the behavior at the cartridge end, but certain evidence shown here seems to support it. That is why, although I believe that to allow the arm to freely with the groove, as opposed to remaining static, is better, I am willing to question it. |
TWL, I think we are having some misinterpritations here, but when we are speculating, as I am, that will often be the case.
I agree with you on all your reasons and speculations behind your mod. I also find them highly intelligent and insightful. I also understand that you are looking for superior tracking. I get the idea that you think that I was implying you weren't. I think that our separation in understanding is in the flexing of the cantilever and the speed that I am refering to. Or, if you will, the offset from perfectly center that is encountered in the circumstances of cantilever flexing.
The speed I am refering to is the warp/wow frequency and the lowest bass frequency. The amount of movement I am refering to are very, very slight. At the level of evan a fraction of a cantilever width. I am not trying to imply that because I can see it, that it exist, or that it doesn't exist if I can't, I use my eyes as an aid. The cartridge I am using is a clavis d.c., and as you know, the arms are an older model immedia and a rb-300. I do observe movement in both, but I don't consider it unusual movement or out of spec. Just to be clear on what I use my eyes for, if I see movement, I use that for a clue, or try to find clues by looking for movement, and then I attempt to identify what I am seeing by checking the set-up and listening.
When the complience and mass of an arm are considered matched, the resonent frequency is suppossed to be between the warp/wow frequency and the lowest bass frequency, I beleive that is 5-10 khz's. THAT is the movement I am refering to. This happens as the cantilever is moving to track the record, which is determined by the mass and complience of the set-up. How much it moves and how fast it moves are two different things, I leave it open for debate as to how much, as I don't know. I know that in most proper set-ups, there is movement, and that it is desired by traditional thinking to minimize it. (I'm still refering to the amount of movement, not the frequency).
While I suggest that your canilever is moving, I am not saying that it is mistracking-the contrary. I have to suggest that it is moving more than it was because by adding weight to a given application and changing nothing else there should be more movement in the cantilever, and that is based on having the arm remain more static than it was. I don't mean to imply that it is more static than it should be, or that there is more deflection than there should be, but I do contend that at the extreme of such an experiment that there will. I am forced to consider, however, that if you increased the amount of movement but changed the other parameters, such as the frequency, or other things that I am not aware, that superior results are/were gained from your experiment at the expence of greater movement at the cantilever. Please don't take that as me saying that you are ignoring movement there, Or that you are not looking to minimize it, or that you shouldn't, but if you don't consider what movement is taking place, or what could take place, then I don't think we can be able to asses the differences that are taking place.
The way I see this, is that adding mass of that amount in the horizontal plane is unconventional thinking, evan as the theory and evidence for it may be sound. I also believe that your assessment of the improvements in sound are true, as I would say from what I have learned from you I would have to guess you are quite competent in that area. All of the evidence that I keep learning as I explore this is leading to this not only being the case, but is causing me to have to stretch in my understanding of tonearms. So I might stretch your theories. |
Oh yes, I gotta try the weights. I would highly appreciate a set of yours, as then I can be sure I am trying exactly what you are using.
My statements regarding cantilever flex are exactly as you say. It is not actually the cantilever that is flexing, but the suspension. That can get confusing. I dont know or remember what that peice is called that the cantilever is attached to, that peice of wire, but anyway, I am observing the movement at the center more or less as you desribe.
The warp/wow that I am refering to is not nessessarily something that I would expect to tame, but the way I understand it, all combonations of arm mass and complience have or produce a resonent frequency, a frequency that is the natural frequency that will cause them to vibrate in sympathy. That is why usually the goal is to set that between the lowest frequency produced by the record, (or for clarification, the music or noise pressed into the record) and above the frequency of the warp/wow.
If the resonent frequency is in a place that is likely to get "exited" then that may have a tendancy to mask or alter the information we want.
I'm not sure if this is conventional, but I am trying to define that there is a difference in the speed of the cantilever movement and the amount of movement altogether.
I'll try to dig up some references so I can be more accurate in my descriptions and definitions, and also you can see what you think if I can find them and get some to you. I also seem to remember the SME use to have a damping trough available, so I'll have to see if any are available. The KAB site I checked out, and the damping trough seemed as though it would require quite a bit of modification for use on a rega, and zaikesman, if you are reading this, it will be very interesting to hear what this does for you.
I also think it would be interesting for us to try and measure these things. If anyone has any info on what is required, I would be extremely interested. |
I'm glad you tried the warped record. I'm having trouble trying to explain what I mean as far as the amplitude of the movement and the amount. I'm trying to think of the proper terminolgy, bot I'm at a loss, as I have been, but I'll try to get closer. I have a feeling you might already be aware, you just can't understand the way I am attempting to explain it, so here it goes. I'll use extremes.
Say you had your anti-skate so off that it caused your cantilever to be way off to one side, (ignore all the obvious mistrackings for the sake of explaining). It would not cause movement of your bass drivers because the cantilever would be fixed. The cantilever has to be in motion, no matter how fast or slow, to cause a signal. (evan one you can see, such as movement of the woofer, but can't hear)
But if the cantilever were to move slow enough, no matter how far from center, there could be still no signal.
So while the movement of the woofer, in real use moves for something like the duration of the movement of the cantilever, it is actually the speed (technically the frequency) that is causing the woofer to move.
To get back to real life for a moment, In playing that frisby, you were able to actually observe the movement of the woofer and still get exceptional sound, yes? That indicates a good macth between cartridge complience and arm, as the warp/wow frequency was obviously present and did not affect the sound quality by causing an unwanted resonence that would interfere with the frequencies you were listening to.
You are right about this, I'm sure of- we will not ever be able to eliminate the warp/wow frequency. It will always be present and the cartridge will always be able to pick it up.
Were you able to observe movement in the catilever/suspention while this was happening? Also, are you sure that the woofers were moving to the sideways motion and not the vertical? In fact, if you follow what I am attempting to communicate, I wonder if you could observe movement of the woofer while not observing movement of the cantilever, and visa-versa.
Let me know if I am coming across, or the proper terminology whatever it is. I can't actually ever recall such a discussion ever taking place. I have more and more questions, but I don't want to confuse things to much just yet.
I found in an issue of stereophile, april 1996, (vol 19 no 4) in the review of the clavis d.c., MF gives a very thorough account of the inner workings or cartridges, this one particularly. He names many of the parts, except what that thing is called that is in front that the cantilever shoots through. It may not relate to our topic, but it may be interesting to you, evan if it may be redundant, so you could tell me more properly what the heck I'm talking about. |
I have finally recieved the HIFI mod for my rb-300, and I have to say that evan though I had ideas of how it would sound, I am stunned.
First off, it is important for me to state that my system is lower in resolution than what I have been used to, and I have to state that it is more than likely lower in resolution than most of the systems that poeple would likely have that wanted to add these sidewieghts. I point the finger solely at the vanderstten 2ci's, while the are sweet sounding, and convey the music, and make the room sound quite good, they lack accuracy. I am not driving them with the best amp for them currently as well.
The reason this is important to say is because to get the 2ci's to stage, to pinpoint, (one of the inherent strenghts of vinal) and to play clean at the same time is more of an accomplishment to be able to hear with these speakers.
The other arm that I am using is an older model immedia. Comparisms are nessesary because frankly right now the immedia is a better arm. It conveys more detail and information. There is roughly twice the cymbal info, separates the midrange instruments better, offers an easier to define bass line.
But compared to the rb-300, the rb does something the immedia can't seem to get. It boogies. The bass is subjectively more involving, more of a tune. The voices of instruments seem to come out with more emotion. While a simple a-b between the two would reveal that to almost anyone, the immedia would be more accurate, and better, what the rb does is impossible to ignore. For me, the obvious goal is to make the rb as good as the immedia. At first, I would understand this to be to somehow make the rb convey the low-level detail of the immedia, stage as pinpoint, and be overall more accurate. Direct comparisms between the two would lead me to believe that most of this would happen in the upper frequencies. So a modification that would seem to take the arm in another direction might seem backwards.
At first, it did. upper midrange information seemed to be attenuated. The air that surrounds cymbals, and the vibrations that pop out and accompany certain voices and horns and lead instruments were the first casualties. But while some of this energy that I would initially seek went away, right at that same place was more depth. I was playing ELVIN!, a record in which Elvin jones is miked up front, with Art Davis on bass to the side and toward the back. This is a great recording for finding detail, as part of what makes it so exciting is Elvin's speed and energy on the kit, and the way it was recorded, there is an abundance of different sounds coming from the drums.
While some of the snap from Elvin quickly wacking the cymbals and rims was not as apparent, And Art didn't pop out onto the room quite the same as I have come to expect, Elvin's kit was also wider, and deeper. Art's bass also had what seemed to me another octave down. I couldn't decide which was better, and I knew I was in for more work in listening. this was going to be harder than I had expected, and it was time to pull out the records that I know like the back of my hand, dirty or not, and wear them evan more.
Next was Van's THE HEALING GAME. There is a track that has a lead bass and another playing the low. And on this record, there is a distinct decay that can be heard of the room when Van sings loud. This would surely tell me something. As I expected, There was more separation between the two basses, But what I actually didn't expect, is the definite lower octave of the second bass, that made comparisms betwwen the two moot. Van also, took up more width betwwen the speakers that before. this is curious. He is undoubtably miked in the center no matter which system it is played on, and to hear a voice take more width, that can easily be disterned is baffuling. At the same time, The back up vocalist, who repeats Van, was farther to the right and back, and more of a pinpoint, and smaller. On to another track, with an opening of an organ. The bass pedal of the organ was deeper. This is the stuff that makes me want to listen to the rb more than the immedia, but I still had questions about the detail and accuracy.
For me, this means getting out Cannonball PLUS, the origional issue. This is my most accurate recording. It starts out with Cannonball's horn which is followed by a natural echo that you can follow as the soundwaves travel acrass the room and SLAM into something and scatter. The bass is recorded up front, and the bass player actually speeds up in his exitement, and the drummer struggles at first to keep up. He seems to be hitting the cymbals harder to keep the pace, so there is cymbal sounds scattering all around.
What I heard here was definite. The bass was definitely deeper, there was another octave down that I have never heard before, except on occasion with my Theta. The air that seemed to be missing from the high frequency energy was shown as a resonence that when missing, revealed the cymbal playing, (which is quite loud and up-front on this record) to be the best I have heard on this record so far. Instead of splashing all around the upper left side, there was a cymbal being tossed side to side, that was definite and discernable as a cymbal being tossed as it is being wacked.
I played more records, but I'll sum up here for now. I was able to decrease the tracking force to 1.65 grams and regain some of the lost midband energy, with no buzzing or other audible mistracking. I was able to visualy dicern the slightest cantilever movement, both with the HIFI and without, but not enough to see at this time whether there was a difference, but it was both less than I have observed with other arms at times and within the accuracy that I usually set up the zenith. All records, in an a/b with and without the tweak had a change in staging, which was wider and more behind the speakers, and that is something that the vandy 2ci's have trouble with. The 2ci's don't pinpoint well, but the differences were audibly "visible" as far as distances before and after.
As for the lost energy in some of the frequencies in the upper and mids, I'm right now of the opinion that it could be replaced somewhere else, that would in the end be more accurate and detialed. I can't be sure whether the energy that is lost is from the start inaccurate in the first place, or whether it is revealing another fault in the arm that was not present before, or whether it is actually a side effect of the tweak. I am sure that it adds positve, more accurate effects, in the bass and in the staging qualities. It moves the overall performance farther away from the immedia, in the tonal presentation and the presentation in the mids, but closer in the pinpointing and staging, (something the damping effects in the immedia, hmmm), but the bass the immedia just can't do.
In the effort to get better sound, more accurate in some or all areas, rather than add to the qualities that are good it is more accurate to subtract those that are bad, evan as it initially seems to go in the opposite direction. In the end this is where transparencey and exitement is.
In my case, the HIFI stays.
And this is just the sound, what it is actually doing I am still with my origional guesses, that are posted above, but I have less doubt that the cantilever is moving in relation to the coils. It is not an issue anymore, as far as damage or evan having a negative effect on the sound, but what is still a guess for me is what it is really doing. The difference in horizontal mass and vertical mass, is still something I think may be something to pay more attention to.
I wonder if this is measuruble, definable and proveable, and I actually wonder what arm may possibly be as accurate in the bass as this. It has taken me a while to write this, and I have actually never heard a vinal playback system have such an accurate, full bass. It would take a direct comparism to know, with more than my humble system.
Its time to step up to the newest of grahams and immedias, the wheatons and such. It is past the older immedia and the rega's. |
Zaikesman, I think we are all a little lost here in this, but that is what I think makes this worthwhile-A better, more sophisticated comprehention of what habbens in this area, which I think is aat the fundamentals of what makes a tonearm work well. Regarding the unmodulated groove, and the output happening in that region, is yes, caused or modulated by the warp, not something pressed into the record.
I think where TWL is on this, that I tend to agree with, is that the cartridge will, and should, be capable of reproducing this, evan as it is artificailly produced by the warp. My guess, which I'm not sure is correct, is that because it is produced does not nessesarily mean that is the resonent frequency produced by the arm/cartridge combo, but am I wrong?
Regarding the transient that you just spoke of, I don't understand this, but it may be what I am trying to understand. Could you please explain with more?
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Oh, I almost forgot, the yoke, what part is that? TWL, the peice I was refering to was not the suspention component, that metal piece with the big hole in it, the one you have to look through to see the coils, often made of brass? |
That is an interesting point. You have strange dreams. Do you ever have dreams where you take an rb-250, cut the armtube and put the lead between the two pieces to make it longer?
Actually, seriously, that is a good point. It makes me want to measure this all that much more. It doesn't seem like it would be too hard to measure the differences betwwen the amount of mass as far as their effect, but I am having limited succes learning how. I got a line on a occilascope, but it will have to wait a couple months. I also heard that you could get a computer program and an a/d converter, but I haven't checked that out.
It would be pretty easy to make an armboard, or make more/other appropriate parts I would think, For me I think the hard part would be figuring out how long to make it and figuring the placement of the mass. Actually, figuring out what exactly the mass is doing in a way that could be calculated.
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Interestingly enough, I did have the vta adjusted like this for the second part of my listening. Before this, I was careful to match the vta to where the vta was on the immedia, which is usually about 1 millameter higher at the beginning of the record with the cartridge just before the lead out groove. While in readings it seems that that is unusually high, both me and my dealer found the same vta for the clavis seperately before we consulted each other. I found this true with the lydian as well. Every other cartridge I have used has been with the vta lower in the back.
That experience alone has made me pay attention to vta. While tonal balance can be affected, I don't adjust vta for it. I don't think that you have either, but right off I would think that the mod is allowing for a set up that is more orietated to extracting more detail, rather than subtracting it in the mod itself. As I have listened to it a little more, I have no indication that there is anything odd or incorrect in the tonal balance. Subjectively I would say it is more correct.
A freind of mine stopped by while I was playing a record, and he commented on how good the system is sounding. He hears my stereo often but he is a non-audiophile.
I am still in the direction that there is improvement to be had in the rb that is more revealed by this mod, rather than that it is just a trade off for the improvement in other areas. I have always thought that the rb sounded a little weird, somehow, in it's energy, and the reviews that I have read, all think it is a great arm but every reviewer, evan those of a glowing review, have something they hear that keeps them from putting it at the top of the best they ever heard, or what they believe is the best, etc.
And also, bear in mind the reputation for the tonal qualities of the immedia.
This is one of the most fun and promising mods I have done in a long time, my own or purchased, or tried from another's idea, maybe the best. I hope you get the credit you deserve, because you (twl) have brought me much enjoyment in the sound evan if I was to leave it at this.
But don't think I will. |
I should be working instead of spending time here, but I can't help myself. Besides, I have had a lot of benifit and fun from the interest this thread has spurned, so I feel I should put in another 2 cents.
Thank you Mr. Rockonroni for mentioning your appreciation. Your description of how it effects how you can easier identify mistracting and setup is insightful. It is helpful that you mention such because besides the obvious advantage of being able to set up better, it is an indication that what is lost are likely distortions, and what is gained is likely more accurate. I should mention that my experience in that area mirrors yours; mistracting errors seem to be easier to identify for what they are, they seem to 'stick out' more obviously.
I think it worth mentioning that although I have not wieghed it, the mass the HIFI adds is closer to the immedia than without, (I say I haven't wieghed it but it is obvious enough it is not nessesary to know that), so the only issue would be the correlation between mass and sonic benifit, not any danger of excess wear or damage (or not functiong or tracking properly).
Furthermore, the sample I got (the only one I have used) came reamed out to fit one the ends, but not with any glue, and I fastened it by pressing it on, and did not use anything to help hold them. They fit pretty darn good at first, but one would occasionally fall off. As this continued they fit less secure. I then put more effort into 'cramming' them on and I noticed the sound improved. Perhaps there is a correlation with the fact that they are lead and right at the bearing, having some sort of damping effect, similar to other mods that have been succesful on rega's. |
YEAH!! I dig tweaking. It sounds like your ideas should work real well for a # of reasons, so here is my pre-feedback on your proposal- I have had great success adding lead to the couterweights of all the arms I have tried it with. My origoinal goal was to increase the mass of the arm (If I recall correctly, it was because I read that this was a tweak applied to the well tempered arm, replacing the counterwieght with a heavier one). When considering this keep in mind that there is a difference between what is referred to as effective mass and mass. Effective mass is the 'effect' that the mass has on the inertia of the arm. As twl states, increasing the mass of the counterwieght and moving it closer is a perfect example of increasing mass without changing the effective mass. Twl's mod is an example of the opposite- the mass applied at the pivot changes the effect in the vertical plane very little, while the effect on the horizontal is increased disproportionally. So, if you were to consider a graham arm with adjustable sidewieghts, and spread the sidewieghts out from the pivot equally, the mass does not incease, but the horizontal effective mass increases because it then takes more force to effect movement in that plane. The vertical effective mass remains unchanged because the weight remains at the same point relative to vertical movement.
The reason I go into this so much is because if you see a picture of the newest version of the immedia arm, you will notice that mr. perkins has moved to a scheme that has the counterwieghts extended out to the sides. He has increased the effective mass in the plane that effects azimuth.
The immedia is a unipivot, so stability in this area is important, and the well tempered is also a unipivot, with a very similar damping scheme.
The rb-series is not a unipivot, so the azimuth is fixed, and while the aftermarket counterwieghts do move the mass of the arm lower, I wonder how much of the improvement is because the mass is lower, or because the properties of energy absorbtion. With a counterwieght that is perfectly round with it's energy transfer dead center, the energy would be reflected back equally and at the same time, and if the point of energy transfer is off center, this may serve to be an effective way of breaking this up. As evidence I would point out the reported success of mods that change the tension of the rear stub of the rb-type arms and they're success relative to these droppoed counterwieghts.
And also, regarding mass for benifits of energy absorbtion, One of the best tweaks for the well tempered arm was arm wrap on the base, and also, the immedia arm first had a base that was very similar to the base of the well tempered arm, until it was changed to the heavy stainless piece it is now, and the success the graham 2.0 has because of it's heavier base over the 1.5.
I am looking foward to hearing about your results. |
Zaikesman, I believe I can explain this phenomena, and it is interesting because it relates to the effectiveness of this mod.
You are correct in your visualization in that in a pivoted arm, movement is restricted because of the fixed position of the bearings, and wieght placement will not alter what the bearings allow, but it can, and does, shift the forces on the bearings and the amount, and this affects the direction of the forces and the resistance to force.
picture a straight rod with a pivot in the center and equal wieghts on each end. if you bend the rod at the center so that one side is down and the other is level, the other side will then wnat to come down as well, evan though you haven't changed the weight on each side of the pivot. now picture the same straight rod with a lot of weight on one end. the location of the pivot has to change to make them balance.
now flip this stuff sideways and consider the pull of the cartridge on the pivot of a tonearm. to shift the mass in relation to the pivot will shift the force on the pivot, just as changing the location of the pivot change the balance of the arm. in the case of the lateral force, or the anti skate, it would shift to one side of the bearing.
if you were to remove the arm from the table and hold the arm so it hangs toward the floor, it would not hang straight down if you had more weight on one side than the other.
with the arm on the turntable, there is no force on the bearing until the record spins and pulls the stylas away from the pivot. with a change in wieght distribution, you change the amount of force required to pull the cartridge from one side to the other. the nature of the hifi mod is to increase the lateral mass as to increase the resistance to sideways movement. to add a weight on only one side will still increase resistance in both directions, but will increase it more in one direction than the other. |
Yes, I should not have actually said, "shifts the forces", I should say shifts the relationship of the forces. It gives the various different forces a different relationship (equation) as they relate to each other.
You are correct- if we hang a tonearm straight down, and get gravity to pull it to one side, and put it on the table again, there is no longer any gravity pulling it sideways. It would not have force to pull it to one side. In actuality, the force of the cartridge on the pivot point does not change either (unless we increase the tracking force).
If we visualize a tonearm hanging straight down with a radically offset mass, you can see that it would take a certain amount of pressure to hold it to hang straight down. And the offset weight is resisting gravity. Replace the gravity in this visualation with the pull of the cartridge. It takes more effort to pull the cartridge one way than the other.
While radically shifting the weight in this manner will not actually pull the cartridge in a direction, it will alter the resistance to such a pull. This then also changes the effect of the pull on other forces. The cartridge will pull to one side more than the other, not because there is more pull in one direction, but because there is more resistance in the other.
This can lead to some pretty deep thoughts on anti-skate. While it is the offset angle of the cartridge is what pulls the arm to one side, the pull is actually directly in line with the cantilever. But, we do see that the cantilever deflecting to one side (when we can see it). To use offset mass as opposed to actually applying an offset counterforce, might be a more effective, and accurate way to deal with anti-skate. |
I think it is worth pointing out that what a properly designed tonearm IS, is the result of continuing to try to improve the design, that is, further the knowledge and design of the technology. That is why it is so much fun that twl shares his improvements with us. Any tonearm can be improved. If it interest you, go back toward the beginning of this long thread and you will see what fun we all had in trying to determine the validity of Tom's modification. There is actually enough here to demonstrate that the modification is of proper design. This is a LONG and old thread. The mod (lateral mass) is proven in listening test, compatability, the theory behind the mod is also put to the test, and it is shown to be an improvement not only to the overall sound, but is a more properly designed arm with it.
If you are truly interested in what a properly designed tonarm is, and want to have real fun, notice how many highly regarded and well designed tonearms DO NOT take note of the the aspects of TWL's design, and if you execute it properly, many arms could be improved the same way. (notice that some arms have uprades that go in this direction). The rb-series of tonearms have some really good aspects to them, namely the design of the armtube and the bearings, as well as some aspects that are overlooked.
The mod works so well that the performance of the arm comes scary close to some VERY good arms, and evan surpasses a lot of very good arms in certain, important areas. It is amazing what you can achieve with a little knowledge of tonearm design. |
There are some really interesting thoughts here in the last few post, as far as thoughts or ideas that eventually turn into knowledge. It is for one useful when we attempt to measure and discover that the measurements are not exactly what we expect- we figure out there is something else going on and we learn something. One thing pointed out here is that the grooves of a record are cut at a 45 degree angle-so then how could a horizontal mass not have an effect on vertical mass? (as it relates to its affect on the suspension). I wonder how these grooves are cut into these various test records that are able to relate to being able to determine separete vertical and horizontal resonences, and wheather these are still existing the same way when the same system is playing a record with grooves cut at 45's. My ears suggest that as I listen to the differences with this particular mod is there is greater channel separation.
We all know that resonence points are important, and tonearm designers are sure to make sure they're designs fall within these parameters. There is also a definite importance on mass, and the placement of such, as it relates to the evacuation of energy, and it is clear in the more recent trends of the better tonearms that have recently added mass to they're arms in particular areas and gained improvements.
A little earlier on in this thread it was brought to our attention that the sidewieghts could be used to effect a change in anti-skate behavior. It made me think about the effects of bearing placement, as it relates to weight (or mass) placement, as it relates to the behavior and tracking ability of the arm. In both the immedia and the sme, the bearings are placed by the designers to minimize tracking error, according to the relative travel of the arm, BUT, changing the placement of the mass in a similar way, such as some of the aftermarket rega counterweights, and the upgrades on the graham, show similar results, without changing bearing placement.
The best unipivots in use today, namely the graham, the immedia, and the vpi, pay close attention to the placement of mass because they have to-it relates directly to the stability of the arm as it relates to tracking- and as designers shift and add mass, they continue to get better results. It is also, perhaps, that as the same attention is payed to pivoted arms, we get the same results, which might lead to the conclusion the while there are advantages to a unipivot as it relates to bearing quality/cost and friction, that perhaps it has more to do with the placement and attention of the mass.
Another case in point might be the popularity and performance of air bearing designs. Very complicated, and while they do show themselves capable of a high level of performance, it was a matter of time until pivoted, and unipovoted arms showed many of the positive aspects of the air bearing designs without the complications. Could very well be, that the sole advantage in actual use, of these air bearing designs is the vertical/horizontal mass relationships inherent in they're designs.
Of corse, the very best arms are very expensive, and rightly so because of the costly construction, as it seems that often certain improvements and uprades are costly to execute. There are some aspects of some costly arms where the quality of the construction relates directly to the performance. And then there are some aspects where improvements are made to the design that are by chance, or because the designer thinks the improvments are the result of what the intention is. That is why this thread is so fun. That is where this thread is at, and that is also why it is so amazing that as TWL comes up with these ideas and experiments that seem to break the rules, it not only forces us to change our perception of what a "properly" designed tonearm is, we make great sounding improvements that I am convinced would further the technology the more we understand them.
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