@intactaudio : " was about the requirement of both overhang and offset to get two null points. Without overhang which requires an effective length to calculate the two null points cannot exist. "
That could be for you but not for Löfgren him self that was who specified that formula, it was not me and certainly not you but LÖFGREN.
As a fact to calculate overhang the most inner/outer values are necessary in the Löfgren A . Effective length is necessary for the overhang calculation but not for null points calculations. Again it’s not me but Löfgren in his A alignment.
R. |
Dear @intactaudio : There is no :Whaaa?. This time you are way wrong/misunderstood on that specific issue .
" you need to specify at least four parameters which typically are alignment type, inner groove diameter, outer groove And Pivot to spindle (P2S.. "" Wrong, you don’t need the P2S that in the standards alignment calculations is not and input parameter in the equations but on those calculations P2S comes only by the difference between EL substracting the calculated overhang and that’s it. P2S came after overhang calculation. Been math on those original equations are manipulations, that everyone can " handled ", like the one made by the SAT designer chnaging the most inner groove radius and then following Lögfren A alignment that in theory achieves lower overall distortion level.
""" As a background note re the ’Löfgren A’ alignment and the null points. Null points are calculated from the inner and outer groove radii selected for alignment optimisation purposes. They are outputs only. They are not the drivers of the optimisation philosophy or arrangement, but rather the consequences of it. Of course, they may be specified for use in an alignment procedure or for when a particular alignment tool is being used, but their specification automatically pre-determines the values of the inner and outer groove radii. For the ’Löfgren A’ solution, the null radii are dependent only on the selected inner (R1) and outer (R2) groove radii,....""""
I can’t paste the equation so I will try to write it for the inner null point for Barwald/Löfgren A/Stevenson B:
R1 inner and R2 outer groove radius.
2 x R1R2 division/ ( 1-1/ divided by the sqare root of 2)R1 + ( 1+1/divided by the sqare root of 2 )R2
That’s the original equation and you can infere from that for the outer null point.
Any one of us can have our self kind of alignment just changing the most inner groove radius and like SAT running Löfgren A calculations. Löfgren B is an " aproximation " ( this is the word used ) that is a little different form the alignment A. There is a long historty on all those alignments and additions to those but the A alignment does not changed in its formulation of null points.
Effective tonearm length has no influence in the null points position. It’s are the same for a 250mm tonearm than for a 300mm one.
R. |
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I like and respect PL of SS, but I would not value his opinion of underhung tonearms any more than I value the opinion of any other smart vinylphile. Then, regardless of what any such qualified individual would opine, I would still want to take a few months to listen in my own home system using a variety of suitable cartridges before forming my own opinion. |
We see in this thread on full display that some are satisfied to rely on reference books, formulae, and theory that can be assessed, studied, and evaluated from the safe, protected, comfortable environment of an office or home, completely avoiding the risk, hazards, and unexpected consequences that may arise, result, or derive from actual experience in the real world. Acting in that way means one will never have to question their "beliefs" which of course are not their beliefs but that of others but it is easy to feel safe, expert, and knowledgeable in such conditions. You can see in this thread that when exposed to data, experience, and knowledge out side of their protected world that raw emotion, bad logic and insults result because they feel threatened or their ego bruised. |
@maxson thanks for your reply. Don't understand then are you measuring VTF off the platter if returning arm to resting position? Trying to picture this but on "conventional" arms I've always measured VTF on platter maybe 1-2 inches from outside. |
@rsf507 Re: Roy Gregory's problems w VTF. I haven't had a problem with this as long as I return the armtube to it's resting postion, a magnet at the outside of the housing that meets a short rod on the underside of the armtube. By returning the armtube to this position during the weighing process, I can be assured that it's in the position that it will hold as it traverses the record. |
@rsf507 , I would guess that @retipper would think you would haven to be out of your mind to buy a Viv arm. He probably would not state that directly as he would not want to lose customers. Manufacturers tend to be politically correct for obvious reasons. Maybe he will chime in. |
Whaaaa??? you need to specify at least four parameters which typically are alignment type, inner groove diameter, outer groove And Pivot to spindle (P2S). The math then returns you two null points, effective length (EL) and offset angle. The overhang (OH) is then found by subtracting P2S from EL. The knowns and unknowns can be reworked based on the information available. Effective length can be substituted with a known overhang and the P2S returned. dave |
Dear @intactaudio : "" The combo of properly set offset + overhang is the only way to get the 2 null points. ""
Well, the standard alignments we all know including Stevenson B the null points are output parameters calculated from only 2 other knowed parameters that are:
most inner groove radius ( mm. ) and most outer groove radius ( mm. ). and from here came the standards: IEC, DIN or JIS. Null points calculation it not depends of any other parameter, not even tonearm EL. Again, that is for the knowed kind of alignments.
R. |
Dover, perhaps to add to what Intact wrote, or not, if you move the pivot forward so the tonearm is not underhung but becomes either overhung or even set to hit the center of the spindle (I guess we can call this "un-hung" or neutral hung), then you can have no null points at all (without headshell offset). Because at the null point, the tonearm from pivot to stylus tip can be thought of as one side of a right angle triangle, let’s call that side A. The distance from the stylus tip to the center of the spindle is then side B of a right angle triangle, and the distance from the pivot point to the center of the spindle is side C, or the hypotenuse of a right angle triangle. Pythagorean Theorem tells us that for a right angle triangle, C-squared = A-squared + B-squared. But in the overhang condition, side A is greater than side C. So tangency is impossible without headshell offset. The un-hung situation cannot work either, where A = C. |
Would love to get Peter Lederman @retipper (SoundSmith) take on this. |
The combo of properly set offset + overhang is the only way to get the 2 null points. If you eliminate either one of those aspects you can only achieve a single null. This single null still requires proper setup to achieve it.
I am starting to believe the effects skating force are painted with much too wide of a brush. One only needs to set a traditional arm with no antiskate on a blank record and note the speed at which it flies to the center. Now take an underhung arm without offset on the same record and in theory the skating forces should identify the location of the single null. This will not be immediate and will take several seconds. The thing that is interesting about this is while both setups do have skating forces involved, the magnitudes of the two are vastly different. One could argue that the application of 'proper' antiskate to an offset arm will result in forces similar to that of the underhung arm but then we have to consider how modulation level comes into play and the need for a big brush to cover up the reality hiding in the cracks becomes clear. dave |
@cleeds You Stated, "Unfortunately, there are some users here who very much treat discussions as a battle where the adversary must be annihilated. They make absolute pronouncements, and then attack any person or product that conflicts with their personal gospel. It stifles conversation." @neonknight has created another Thread seeking ideas about Tonearm Alternatives for a owned model. 'neonknight', as an extension of the earlier started Thread and I assume as a result of looking into the world of Tonearms. Has most likely made a discovery that got his attention. The want has been expressed to learn a little more, resulting in creating this Thread, where there is a inquiry about the Viv Lab Tonearm, resulting in the following: "I am trying to do my due diligence about this arm. I am just having a hard time getting my head around this idea of zero overhang and no offset. Does this arm really work the way it is reported to do?" Six Pages have followed, where it can be seen, reports offered by users of the Viv Lab Arm, have been denied the validity being made known about their experiences and the Good Impression made. Viv Lab Arm Users have even made it known that they have had it supersede other Brand Tonearms that show up regularly as a Tonearm to aspire to, or seen as a recommendation to others to seriously consider. The Thread has a healthy motivation, as it has certainly been with a content supplied through the positive information, through the reporting on user experiences, that has encouraged other to investigate further and in some cases create the chance to experience the design or a close alternative when possible. Hoo Rah for that as a outcome, nothing ventured , nothing gained. Certainly no noticeable 'contempt prior to investigation' from this group of inquisitive types. The most noticeable alternative approach to the Thread from the above two outlined approaches, are looking to be from individuals that have completely misunderstood the Op's inquiry. These individuals have approached the Thread to do the utmost best to impose their interpretations on why a Overhung Geometry is the only configuration worthwhile considering and why the Underhung Geometry is not worth any consideration. It is this approach that is seemingly way 'off track', pardon the pun, and quite a distance from the OP's initial inquiry. As a basic evaluation, the OP, has still got an interest in the Viv Lab Arm and has made inroads to learning how to acquire one. Users of the Viv Lab Arm, do not appear through their reporting, to be swayed to making a change to an alternative arm. A few very experienced users of the Vinyl Medium have and are to actively create an experience of the Geometry of the Viv Lab Arm. This is where I connect with the Thread. A 'minority' are left licking their wounds to fight another day, 'there is certainly no winners in this camp' the arguments presented are off topic. Looking at the follow up the the posts made from this camp, it does look like the content has been dismissed as being, not of any use by many readers of it.
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You have misconstrued what I am suggesting. I am suggesting keeping the headshell offset at 0 ( straight ) move the arm mounting point forward in order to set 2 null points. The 2 null points could be anything, for example 1/3 & 2/3 across the record. The 7 inch arm is probably not possible, but certainly the longer ones could be set up this way. My gut feel is that the straight headshell has more impact than the "underhung" geometry. With the "underhung" claimed by VIV I don't get it. If you look at their set up template their null point is in the middle of the record playing area, which means that irrespective of the "underhung" set up, skating forces are going positive and negative as the cartridge tracks across the record. If they set the null at the end of the record, then the skating forces would always be in 1 direction only, and therefore much easier to control. |
rsf, In my opinion, the pivot point should be fixed in space. I do not view Roy Gregory's report that you cite as a good thing. Dover, I have to think about this some more, but off the top of my head, I do not think it is possible to set up an underhung tonearm so as to achieve two null points on the surface of an LP, no matter what you do with the headshell offset angle. Also, I disagree with the Viv website, if they say that the combination of zero headshell offset angle and underhung-ness has the net effect per se of reducing the skating force. What it does do is create a smoother more linear transition in the magnitude of the skating force as the stylus traverses the LP surface. Maybe this factor makes the high TAE at extremes of travel more benign than it would be in a conventional pivoted tonearm. Just guessing. |
@rauliruegas I thought it was a simple question. Since I’ve never used or seen a ViV arm and in the review Mr Gregory said it was difficult to get an accurate repeatable VTF, the question was aimed at those with direct experience, is getting repeatable and accurate VTF with this arm? |
Dear @rsf507 : I could think that you already know that the recording/playback overall process is full of imperfections and trade-offs.
Could you share which is your target doing that question? or maybe you already have the answer.
R. |
From a review by Roy Gregory
Question? Is the setup very frustrating? Can VTF be dialed in accurately and consistently? |
There are 2 elements to the VIV Lab arm -
What would be interesting would be to set the VIV Lab arm with 2 null points and straight headshell and compare that to the underhung geometry with straight headshell. Then we would get a more accurate picture of the "underhung" vs 2 null point impact on sound. From my reading of the VIV Lab notes It would appear that the zero offset headshell has more impact on reducing skating forces than the underhung geometry. From the posts thus far in this thread we have no idea of whether 1 or 2 above is the major factor in the VIV Lab sound.
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Raul, I get your position vis a vis tube vs transistor. You are entitled to it. But you cannot seriously be thinking that the idea of an underhung tonearm is or ever was foisted upon us by the evil "AHEE", can you? I hope not. It's quite the opposite, as I think you know. Not to mention that in the early days of SS, transistors were promoted heavily by the AHEE, as against the then prevalent tube devices, just because of the lower HD measurements, never mind that very low HD was achieved at the expense of tons of NFB. It was only after about 10 years into the SS era that tubes made a comeback, partly because of Harry Pearson and TAS and partly because of Bill Johnson and his Audio Research. Yes, I guess you could say that HP and TAS would come to personify the apocryphal AHEE, in the eyes of some. Anyway, I think we have reached a point where we now have superb devices that use tubes and equally superb devices that use transistors. There's room for both in the present audio universe. |
Those are my thoughts exactly. Unfortunately, there are some users here who very much treat discussions as a battle where the adversary must be annihilated. They make absolute pronouncements, and then attack any person or product that conflicts with their personal gospel. It stifles conversation.
Me too, but I’m a curious guy by nature. Even though I have no plans to change from the SME V arm I’ve enjoyed for decades and have never heard an underhung arm, I’d jump at the chance. It would be interesting to discover if I could hear any correlation between the sound and the unusual geometry. |
Dear @gibsonian : " All tube system (SET best) and a Viv tonearm and sound like all the intoxicating distortions that "audiophiles" have adopted over the years will be enhanced to new super pleasing levels. Not surprising is it? "
No, not surprising because is what they like the more and that is the whole education all of us received by the corrupted AHEE where we all belongs.
Of course several audiophiles were and are excellent " students " even some of them with post-grade AHEE education and some others like me not really good. I love MUSIC and I learned to respect what that means taking actions against that corrupted education I received by AHEE . Through the time my audio ignorance levels improved thinking that way but " diversity " is part of the human world.
There is rigth now a thread where the OP wants to change its tube phono stage but AHEE post-graded gentlemans insist with that alternative even that he posted 1-2 times that wants to change:
R. |
@lewm I am open minded on this subject. The Thread has been a prompt, and as result, I have the opportunity coming to encounter a version of Underhung Geometry. I have no intention on commenting on Underhung or 9" vs 12" Wands until the upcoming experiences are complete. As all demonstration will be using the same fundamental Tonearm Design on the same TT, the the same Brand / Model Cart' with almost identical usage hours. This type of demonstration is not too common and will be the first time I have been able to have a comparison that has set up conditions so closely matched.
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@lewm , I am at Vail skiing so, pardon the delay. There are standard answers to ink plot tests but as anything with humans there is a bell curve distribution of answers. Most regular folks are going to think the Viv arm sounds fine. Those of us at the higher end of the bell curve are going to think it sounds like sh-t. When given the test all I could say was "it looks like and ink blot." Shows you how imaginative I am. Distortion is like fog the heavier it gets the more impossible it is see / hear. Systems with really clear vision put distortion on Viv-id display. |
Pindac, Speaking for myself only, and possibly for some others, I do not view this discussion as a debate where there could ever be a true "winner". I champion the idea of an underhung tonearm as a novel idea that deserves some thought and attention. I have never heard a Viv Float, so I have no strong convictions about the performance of that particular product, but I have heard an RS Labs RS-A1 tonearm, because I own one. The fact that it does so many things directly against convention (besides the fact it's underhung) and yet still sounds very good first started me thinking whether we should question some of our tonearm gospels. And I am still at that point. |
@intactaudio : For an experienced " ears " gentleman as you that audible/inaudible always be served the best by a true high resolution system specially through its electronics/speakers
I hope you are not using tubes down there that could " vanish " true high resolution I can think that the choosed LP tracks were the ones you know as the fingers of your hand and I have not doubt about but curiosity for the LP choosed tracks because some of them could be a test reference for me and maybe to other audiophiles. Thank's.
R.
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@intactaudio As stated previously, I was out of this Thread. Other Posts have caught my attention. "Could you detail your room/system and the LP tracks you are using for your listening tests?" "It is an interesting but extremely complicated and hard to fathom, not tonearm design but the psychology behind human hearing." If submitting your decor' materials, specific room treatment materials, and positioning of structures within the room. It will be a great help if the information can be supplied about whether there is a Window present and if it is observed from the listening position. Can the Colour of your Curtains/Blinds be made known, and if these were pulled closed or remained open, as such a impact of color can have a real effect on the effect of Psycho Acoustics and could easily make your report contain a deficient content 🤣🤣 Somebodies desperate to to win over this Overhung/Underhung thingy that is going on. The Hay Makers are now being thrown, desperate wild swings from the ones who have found themselves on the back foot once more. The two statements made above, should become/not become (I know my leaning), the new precedent being set, for a qualification required to be revealed, prior to all subjective appraisal being offered up. The last qualification for a subjective evaluation having gravitas, that I recollect as being made by one of the producers of a above statement. Was that there was a visitor who was a Orchestra Member? and the description offered of the visitors appraisal and opinion, was to be taken as the proof of the perfectness of a system demonstration that took place. To cast doubt on the findings during the demonstration, the visitor was not even Blind Folded during periods of replay to be evaluated.
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Dear @intactaudio : "" Maybe the distortion caused by this is inaudible to some people, but it is there and is audible to some of us. "" That statement comes by @mijostyn and I agree with. Audible/inaudible depends basically on room/system accuracy levels and resolution levels not only your " ears ". Could you detail your room/system and the LP tracks you are using for your listening tests? Thank's in advance. R.
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Ahh like the old Vace-Fase illusion you get a 50-50 shot at getting correct. I did a google image search and got about 3 images into an online test and it was funny how you would look at the image and then tick a checkbox from a list of possibilities on the next page. Ya gotta like the power of suggestion to make you see / hear things. dave |
@intactaudio , it is always safe to assume the math is always right especially when it comes to human hearing. Just because some obviously defective designs sound OK to some people does not make them any less defective. It is an interesting but extremely complicated and hard to fathom, not tonearm design but the psychology behind human hearing. I think it is analogous to the Rorschach test. Show 10 people an ink blot and you will get ten usually different impressions of what the ink blot looks like. The same is true of sound. It depends on that person's experience, preferences and state of mind. |
@lewm, "nothing" is the ideal goal. The tonearm's job is to hold the cartridge rigidly in the right position to do it's job having only two degrees of motion, vertical and horizontal. The right position is tangent to the groove with a SRA of 92 degrees and a stylus azimuth perfectly perpendicular to the surface of the record. The tonearm can not resonate in any way and should have frictionless bearings. There is no perfect tonearm, but in evaluating tonearm designs I think it is helpful to keep this in mind and make as little compromise as you can, picking the compromises that are least harmful. When you add into it that you are dealing with a sprung suspension and an unavoidable resonance problem the cartridge itself becomes an important factor in the design of every tonearm and has to be kept in mind. So, there is this push-pull situation in tonearm design. Fixing one problem makes other problems worse. I believe, since there is always a threshold under which problematic issues become inaudible, the appropriate approach is to minimize all the problems in a balanced fashion and hopefully bring all of them in below the threshold of audibility. Many very smart engineers have looked at this problem and the vast majority of them have decided that the 9", pivoted, offset tonearm does this best. Newer tonearm designs utilizing the Thales algorithm like the Schroder LT and the Reed 5A and 5T may advance tonearm design to the next level. The principle makes enough sense that I would be willing to try it. Carriage driven tangential tonearms also make sense but are much more complicated and expensive to make. I put air bearing arms and this Viv arm in the same category, arms that optimize one or several factors at the gross expense of another which I find unacceptable. Maybe the distortion caused by this is inaudible to some people, but it is there and is audible to some of us. Lew, if you look at the business end of the Schroder arms he uses the same design on all of them, a cartridge mounting plate is attached to the end of the arm with one screw in a slot. So the cartridge can be twisted within a certain range and the overhang can be adjusted withing the range of the slot. If you mount the cartridge with only the inboard screw you can twist it straight and slide it back creating an underhung arm without any offset. This may not work with all cartridges but it does with the MC Diamond because I tried it. This configuration definitely caused enough havoc with imaging that I am pretty sure I could pick it out reliably in a blinded AB situation. |
Pindac, I’m sure you know this, but because you did not mention it, I hope your underhung tonearm will be built with zero headshell offset angle. Dave, in your aural experience reported above were you listening to an RS-A1, or what? Also, what is “arbitrary distortion”? Could it also be called “subjective distortion “? Thx. |
@intactaudio Dave good to see the inquisitiveness ( the quality of wanting to discover as much as you can about things), is proving to be availing. I was off this thread, but my visit and your last post has got me 'back in the game'. As said, I have been fortunate in having it agreed a New Tonearm Design, I am being asked to be present for a demonstration and offer a assessment of the demonstration experience, has been agreed to have one of the models set up as a Underhung Geometry. It will be a rigidly coupled Mounting, it will be used in comparison to the 9" and 12" Overhung Geometry. The length of the Arm to be allocated for a Underhung Geometry is yet to be made known. The Plinth/Chassis will be able to mount Two Tonearms to a 12" length. The demonstration is to use a Two Cart's, same Brand/Model with very similar hours of usage. The Tonearm Design also has a Geometry, that has the Styli when in the Groove at the same height as the Vertical Bearings Axis Pivot Point. Your taking the time to create the experience and evaluate, has been a added boost to my intentions. I am keen to see what is able to be created and where the attraction of the Geometry can be discovered, in relation to the Overhung alternative. As per usual, whether Overhung or Underhung, all assessments will end up as a subjective evaluation, that is to be made through drawing from multiple years of experiences of being demonstrated multiple differing HiFi related Designs being put to use. There is a Computer Programme available occasionally for System Health Checks, especially for a Vinyl Set Up. The use of this on a well known system produced a end result, where the improvement in the presentation was by myself perceived as almost Tangible. The imaging become very focused and the performers were more present than what was remembered. This Software might? be available for the demonstration day as well. It will be used at some point to give the New Tonearm Design the fairest of lore, as getting the Cart' optimised in its set up Geometry will go a long way to help learn as much as can be offered.
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My best guess is for some reason the underhung arms handle the TAE differently than a traditional arm. I think i would liken the sound to that of the conical vs advanced profiles. In all but the best setups the conical will sound better but leave a lot of the music in the groove. If you want a quick simple setup that will sound good use a conical and an underhung arm. If you have the ability / time to nail the setup an advanced profile on an offset arm will be better. For some reason in spite of all of its problems, the RS-A1 can get plopped down and be playing music in 5 minutes at a level of a fairly well set up traditional arm. I am about 12mm and I would listen to the last track as a test for alignment. For the last third of the record the single null moves about 3mm toward the spindle for every reduction of overhang of 1mm. Zenith also plays a role here and the chances of actually getting it to 0° is slim so this will change the theoretical ideal. I suggest starting with coarse moves and the last two tracks of a side since thats where the gross errors are most apparent. I do want to note that unlike the three underhung arms discussed here, the arm you are going to try this on is rigidly coupled in all but the lateral and vertical planes so i would be very interested in your results. At the risk of giving all of the naysayers here some ammunition I believe this is what the math says about the resultant distortion of an overhung and underhung setup. It is this huge disconnect between what the math says and what people hear that has me interested in this topic. dave |
Do you detect a greater uniformity of any colorations, from lead in to lead out grooves? That's what I thought I heard with the RS Labs, less in degree and fewer variations in sonic character, compared to a typical overhung tonearm, as it traverses an LP. Which made it sound more like a good R2R playback. (That's my best metaphor for it.) This effect was not probably as great as may come across in my writing about it, due to the fact that we must use words to describe it. |
All of the offset is applied at the single mount screw. The only thing preventing a 0° offset is the back of the cartridge hitting the armwand. I made a shim to get the clearance so the cartridge could be set straight. I looked at the math and suspect the best setup for this type of arm puts the single null point about 80% of the way into the record. I have found that the predicted distortions by the math need another factor of 2 added beyond the traditional weighting to match what I hear. I also suspect stevenson was on the right track since things get really ugly as you pass the second null and approach the lead-out groove. dave
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