Dear @jtimothya : It's not M.Fremer or any other reviewer or tonearm designer whom started to " discuss " about, no.
All kind of alignments ( even personal ones. ) equations calculations ( Löfgen was the first one. ) shows three main set up parameters:
overhang, offset angle and two null points. These is inherent on all kind of alignments.
Why those two null points, other that tell us that there the pivoted tonearm cross tangentialy with "cero " tracking error?
Well, those null points define three LP surface areas where in each one exist ( normally ) diferent distortion levels. Where those null points been calculated define the distortion levels at those 3 LP surface areas : the area before the first null point, the area in between both null points and the area after the second null point. That's it.
Rgards and enjoy the music,
R. |
Something just occurred to me: Is the offset angle required for Stevenson much more acute than that which is required for Lofgren and Baerwald? I think it’s the opposite, because of the aforementioned need to twist the cartridge inward on a Stevenson tonearm aligned for L or B. This would mean that there is more skating force at the null points with these latter two geometries, compared to Stevenson. That would be a point in favor of Stevenson. Just a thought. I’m not sure, but I believe so (Stevenson = more acute). Last night, I looked a bit more deeply into the Elison spreadsheet. The values for cells F3 and G3 are looked up in columns W & X. I believe you need to generate a set of Stevenson figures for these two columns. My Excel chops are a bit rusty, but this much is apparent. If anyone knows the answer to this, I'd appreciate it. It might be time to contact John. Darn you Lew! ... I have so much on my plate and yet this topic is really gnawing at me ;-) Cheers, Thom @ Galibier Design |
Hi Chakster,
I'm with Raul - that if this concerns you, that you should experiment. Even Lew stated that he felt uncomfortable about generalizing his resonance experiment across other tonearms.
Cheers,
Thom @ Galibier Design
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@thom_mackris
I’ve tried Stevenson for victor ua-7045 on luxman pd444 and it sounds great (no matter LPs or 45s). First cartridge was AT-ML170 OFC mounted at AT technihard shell (at-lh13). The little twist is hardly visible, but i’ve done so to set it up in dead accuracy by Dr.Feickert.
Now i have Victor X1 with Grace HS-6 headshell on the same arm. I use Baerwald, but i sill have to twist the cartridge in headshell even more.
I think Victor UA-7045 was designed with Stevenson alignment in mind, correct me if i’m wrond.
My Reed 3p was designed with Baerwald alignment in mind and this is what i use with Feickert. With Pioneer PC-1000 mk2 the sound is fantastic. I love this cartridge even more now.
Long before i get Dr.Feickert i used protractor from Hi-Fi News Analogue Test LP (they call it Linear Offset technique.) It’s Baerwald and works fine for "12 inch tonearms, there are no errors when i use both now to doubleckeck the accuracy of the old one compared to new.
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Agree with Lew. On an arm designed for Stevenson (or close), to get a Loefgren A or B requires moving the cart forward and increasing offset angle. I've done this numerous times for people who wanted a Baerwald alignment. Often such an alignment wasn't possible because the headshell slots weren't long enough. If the mounting distance is fixed, these alignments require greater overhang and increased effective length. You can use an intermediate alignment if desired, in between Stevenson and Baerwald. Contrary to popular belief, such an alignment is legitimate. Chakster has a good point. If the offset angle is in agreement with the arm design, there might be less torsional force on the cantilever. This might be especially true in arms with removable headshells. fleib |
Interesting the debate over the 3 main alignment curves, how most can detect differences in tracking errors depending where on the lp one is tracking and everyone has a favourite alignment. Mine is Stevenson as it sounds better/cleaner than the other two on the last 3rd or any lp.
I recently got a Thales Simplicty II tonearm and the maximun tracking error is 0.0006. far less than any of the 3 other alignment’s. You can hear its superiority, more than any other tonearm I have heard, you can’t tell where on the record the stylus is, the music is clear and just sounds right. So far there is no downside in my listening.
We have Kuzma, Trans-Fi , Ckearaudio and Bergmann that have traditional linear tracking - some say with drawbacks.
We now have pivoted tangential tracking with Thales and Schroder.
Tangetial tracking is what most audiophiles should be aspiring to right? You no longer have to worry about what alignment sounds the best compromise.
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downunderTangetial tracking is what most audiophiles should be aspiring to right? Not necessarily. Tangential trackers introduce their own set of problems including higher friction and noisy fiddly air pumps, depending on the arm, of course. Other so-called tangential trackers rely on a servo to maintain tangency, so there is periodic deviation from tangency as the servo "hunts" to correct it. Some audiophiles consider most linear trackers to be a cure worse than the disease. |
Downunder, I don't think we're really "debating" the 3 curves so much as we are talking about what curve is optimal for what tonearms and why. I recently got very interested in tonearms that have zero headshell offset angle and are designed to be mounted with "underhang", which is to say that the stylus tip does not overhang the spindle; instead it is set short of the spindle such that the tip is on the playing surface when the tonearm is pointed at the spindle. With such tonearms, of which there are only two I think, tangency to the groove is achieved at only one point on the surface of the LP, not two, and the most extreme tracking angle error can reach or approach as much as 10 degrees, at the most inner and outer grooves. (But it's more typically 5 to 8 degrees at worst.) BUT, on the other hand, there is zero skating force at that one null point.
What to do with this information? I have long owned an RS Labs RS-A1 tonearm, which is one of the two commercially available arms that use underhung mounting, that I know about. I always wondered why it sounded so good, despite its other rather gimmicky features. Then more recently, the Viv Rigid Float tonearm came on the market, which also uses underhang. The Viv company likes to talk about their floating bearing, of which I am a bit skeptical, but the arm gets great reviews and is revered in Japan and Europe. I think the reason that the Viv and the RS Labs may punch "above their weight" may be that the skating force produced by headshell offset is more noxious than the skating force that arises due to lack of tangency before and after the null point(s) for any pivoted tonearm. And by extension this suggests that our obsession with minimizing degrees of tracking angle error via headshell offset is possibly unwise.
Does anyone own a Schroeder LT? I rather like that one. |
Since downunder raised the point of alternatives to the "big 3" for alignment, I'll further muddy the waters by suggesting yet another. This one comes from Allen Wright's site for vacuumstate. I happen to own one of his JLTi phono stages, but that's another story. He attributes this alternative alignment to someone named Rowan McCombe who he calls "The Guru". I've traditionally utilized Baerwald but currently have The Guru alignment and enjoy it's musicality without any hint of distortion. http://www.vacuumstate.com/fileupload/GuruSetUp.pdf |
Dear @chakster : The 7045 is good tonearm and he 170 is very good tracker and this cartridge characteristics means that with or with out Stevenson alignment it will ride perfectly the inner grooves .
Again, your music/sound priorities are very personal and you have to use what fits it and that's all.
Regards and enjoy the music,
R. |
Dear @fleib : I play several times with my 505. I almost not used the Dyna dedicated headshell but several others. I never like it what I heard it with what Dyna recomend alignment that's ( if I remember ) not exactly Stevenson ( maybe I'm wrong an it's. Never mind because this not the issue. ).
When I used, either, on it the Löfgren A or B alignments I let all parameters in those alignments in orthodox form.
That is what works for the best for me in that tonearm even that you can be rigth about that " torsional force in the cantilever " that maybe could stay at minimum with cartridge that has very good tracking abilities.
For me has no sense ( even if I can be wrong. ) to sacrifice over the 80% of the recorded area in favor of " nothing " because as I said to @chakster : with good trackers we can't detect " problems ".
Regards and enjoy the music,
R. |
Dear @downunder : It's not the third part of the inner recording area but a lot less, never mind.
Yes, it's better a pivoted tangential tonearm design as the one you own, no doubt about but tonearm design is not only if its run tangentially but several other critical subjects for the cartridge can shows at its best.
Regards and enjoy the music,
R. |
Dear @pryso : There are nothing of exceptional/new down there even than the ownner of VS said he had no explanation where comes those null points values.
Look, I posted several times and I think here too that for alignment calculations there are 3 fix parameters: effective length, most outer groove radius and most inner groove radius.
In you link Cotter used the IEC outer radius and changed the input inner groove to 66. What did it that " guru "? the same he changed the IEC radius on the inputs calculations.
Exist no " black thread " about but only manipulation of the input calculation parameters.
What did it Stevenson?, as @fleib pointed out he did not touched the outer radius but the inner one where he forces that the inner distance coincide exactly with the second null point. That's all.
If you read the Analog Planet link that was posted here, I posted there that that " black thread " discovery ( even new for MF. ) for the uni was only a manipulation of the most inner groove radius and I said it its value.
Many people puts angry with me when I use the word " ignorance " but it's tru when we don't have the rigth information we are ignorant on that and what we read could seems to us as the century's discovery when it's not.
You like it that alignment not because it's better but only that tracking error/distortions changes of surface LP position.
Regards and enjjoy the music,
R. |
Dear @lewm : On your take about the Vivid floating tonearm design it's ovbious that you are just speculating about the AS issue.
"""
but the arm gets great reviews and is revered in Japan and Europe. ""
several people when listen something diferent and especially when the audio item manufacturar touted its " great design " almost always all ( especially reviewers. ) " revered ". Sometimes like in your example is by ignorance sometimes because they like those biased diferences and sometimes those biased differences are no more than higher distortions. In that regards about the " underhung " the design has no real foundation and the manufacturer speaks only on what the listeners heard it but with out single fact on its design and why is " so good ".
Mathematics always helps and you are an advocate to. What happens with the " underhung " higher eror(distortions?
Anyway, maybe all of us have diferent opinions about and maybe no one has the rigth one. That's why exist the so many forums in the internet with so many " hot " discussions. Is part of the audio fun where all we can learn.
Regards and enjoy the music,
R. |
Lewm, When Loefgren published his alignment(s), he equated alignment error to distortion. I wonder if any attempt has been made to qualify or quantify this assertion, what kind of distortion and how much? Aside from a very small amount of phase error between channels (we're talking about rotation of contact area within the groove), it seems to me most error is subtractive and would not qualify as distortion. With underhung straight pivoting arms, reduction of torsional forces on the cantilever is also said to be a function of no offset angle and skating is reduced to the extent that it becomes unnecessary. Yamaha offered such an arm as an option on the GT-2000. It is the YSA-2.
http://www.audiocircle.com/index.php?action=gallery;area=browse;image=122280
Regards,
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Raul,
Appropriate to the subject line for this post there are three primary alignments commonly used, identified by the names of the men who developed them. I jokingly referred to them as the "big 3".
My reason for commenting yesterday was to add to downunder's mention that other alignments have been put forth. I was not suggesting The Guru method is the best, only that I tried it and found it enjoyable. I attached a link in case anyone else might be curious to try it as well.
Peace
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Lewm & Fleib:
The RS-A1 is a bit different as the cartridge is able to rotate and (possibly) maintain tangency to the groove. In Viv Lab and the Yamaha YSA-2, the cartridge is held straight and thus the cartridge will at the beginning and end of the record be at a ~10 degree angle to the groove.
Some thoughts:
1) The distortion resulting from the stylus being at an horizontal angle to the groove is 2nd harmonic, which I believe is the least harmful distortion.
2) It is not clear to me how different stylus shapes affect the distortion resulting from being at angle to the groove.
3) The calculations only cover horizontal alignment and it’s not obvious to me what the resulting distortions in the vertical part of the stereo signal are and whether these are dependent on the frequency (highly likely) and stylus shape (also highly likely). In particular, it is not clear whether these are 2nd harmonic or something else.
4) This horizontal alignment is the only kind of distortion for which I have seen a calculated estimate. Does anyone know of estimates for the distortion resulting from skating forces or vertical misalignment and whether these are 2nd harmonic or something else? I recall reading a discussion of the design of the Viv Lab where the designers seem to have been concerned about skating forces and considered the related problems worse than those related to horizontal alignment.
5) I’ve only seen one graph claiming to show the actual measured distortion from playing a test record. I came across this on the web and do not know if it is authentic. It was claimed to be from a Yamaha test of their YSA-1 (~Stevenson) and YSA-2 (straight) tonearms. Does anyone know of actual measurements of the distortions?
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Sampsa55, Interesting post. Vertical alignment error (SRA/VTA) can be measured with a test record and a distortion analyzer. I've never done this. It seems to me, it will vary somewhat from record to record and I adjust it by ear and on the fly. Most people hear this as an imbalance -bass to treble which seems more obvious than tonal and harmonic inaccuracies which I also hear. You say alignment error causes 2nd harmonic distortion. Is this documented? While vertical error is readily heard, horizontal is not so obvious. Adjusting alignment provides clarity and focus. Is this measurable 2nd harmonic distortion? Conventional pivoting arms only have 2 nulls across the record. It's the movements of the cantilever which trigger the generator. Reduction of torsional forces from anti-skate and offset is said to be responsible for increased clarity. The RS-A1 also addresses vertical torsional forces by aiming the cantilever at the pivot vertically. The rotating headshell seems a compromise between alignment and offset. There was a Grado Signature Laboratory arm which had elevated pivots and fixed alignment - offset. Regards,
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You say alignment error causes 2nd harmonic distortion. Is this documented?
It's in Baerwald's original derivation from 1941, where he shows the resulting distortion to be primarily 2nd harmonic. |
**It's in Baerwald's original derivation from 1941, where he shows the resulting distortion to be primarily 2nd harmonic.** Not to be argumentative, but that's hardly convincing. The distortion analyzer wasn't invented until '41. What did he use as a test record, a steady tone on a 78 ? For those unfamiliar with the history here, Baerwald didn't invent the alignment which bears his name. He popularized the Loefgren A alignment which has lowest average error. Loefgren B has lowest total error, primarily because nulls are closer to the center of the band where error is greatest. Sampsa55, I'm not saying 2nd harmonic is wrong, I don't know. Perhaps there is a more recent testing? Regards, |
I wasn't referring to a test, but to Baerwald's math models where he derives the distortion resulting from the stylus being at at angle to the groove and the results show the 2nd harmonic dominates. I don't have Loefgren's original paper, so I don't know if the result is even older. (Stevenson wrote his in 1966.) I'm sure it has been tested too.
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Found the Löfgren article from 1938 (and a more recent translation from German to English). One key assumption Löfgren made in calculating the distortion is that the lateral stylus tip velocity is 10cm/s. It seems others followed this assumption and for instance the Ellison Excel sheet is based on it. This will scale all the calculations and hence is key in understanding the magnitude of the problem. This assumption was made in the time of 78s without RIAA correction, so I’m wondering about the extent that it’s still valid. Here’s the quote in Löfgren (p. 355): Die Schnellenamplitude überschreitet wohl selten 10 cm/s (11), entsprechend einer Lichtbandbreite (12) von etwa 25 mm. The citations (11) and (12) are: (11) H. J. von BRAUNMüHL und W. WEBER, Einführung in die angewandte Akustik. Leipzig 1936, S. 106. (12) G. BUCHMANN und E. MEYER, Eine neue optiselle Meßmethode für Grammophonplatten. Elektr. Kachr.-Techn. 7 (1930), H. 4, S. 147—152. Just came across Gilson’s 1981 article in Wireless World that is quite interesting. I’ll just leave these quotes here without any comment (p. 61): It shows simply that the lowest possible tracking angle errors can be achieved only at the cost of increasing the values of F and t; and conversely forces F and t can only be reduced by accepting increased angular errors. In the absence of published information on the audible effects of the opposing factors, the optimum balance is anybody’s guess, but it is hard to see justification for the assumption that the lowest possible angular error must necessarily be the best condition. In thinking about these problems, it is necessary to keep a sense of proportion; tracking error is only one source of distortion and possibly a minor one. Probably the worst source is tracing error, which can easily run into double figures percentage at the inner grooves, particularly with slight stylus wear. Then there is vertical tracking angle error, which is difficult to avoid. Another source is that due to any longitudinal compliance in the stylus/armature system; it is usual to mount the cantilever in an elastomeric grommet or block, and this is not adapted to providing much rigidity in the longitudinal direction.
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Sampsa (and Fleib),
Just a few things:
While it does appear from visual inspection that the headshell of the RS-A1 might rotate in order to maintain tangency to the groove, this actually does not happen, because the wires from the arm wand to the cartridge are stiff enough essentially to prevent it from happening. Moreover, the English translation of the designer's white paper suggests that he never intended the headshell to rotate. Rather, he is seeking to decouple the headshell from the arm wand. (This is claimed to be so beneficial that the headshell per se is available as a separate product, which could turn any conventional tonearm with a straight pipe and interchangeable headshell mount into an underhung tonearm.)
With the Viv Rigid Float, if you choose the 7-inch version, then indeed the tracking angle error at the extremes will be about 10 degrees. However, if you choose the 9-inch or 13-inch versions, the max error goes down commensurately. While we were in Tokyo, and I was wrestling with the decision to buy one or not, my back of the envelope calculation was for about 5-7 degrees with the 9-inch version (the one I would buy) and less than 5 degrees for the 13-inch version (which I would not buy because I have no turntables that could mount it at the recommended distance from the spindle, and because I think the 13-inch arm wand raises other issues of effective mass and resonance). It's obvious that the inventor of the arm has run into objections related to the tracking angle error with the 7-inch version (the original sole specification) which led him to create the 9- and 13-inch options. I did not buy one, but the temptation will not go away, because our son lives in Tokyo, and the tonearm (all 3 versions) is on display at Yodibashi Camera in Akihabara. |
Lewm, If the RS-A1 headshell doesn't rotate, then the only other unique feature the ViV brings to the table is the floating pivot. I'm not sure how significant this is, but I suspect you already have the better sounding arm. If the goal is to reduce torsional affects on the cantilever, your RS-A1 also does this in the vertical plane which might be more important than lateral. Vertical angular error is more noticeable and more readily heard, IMO. This might also apply to vertical torsion? I've read a couple of reviews about the ViV and they both said the 7" arm sounds best. Conjecture was, this is due to reduced resonances. It's a little hard to imagine how 10° alignment error could sound better than a lesser value, but conventional wisdom doesn't seem to work here and it would be interesting to compare these two to the Grado Signature. That one has vertical displacement and an SME type headshell with conventional alignment.
http://www.vinylengine.com/turntable_forum/gallery/image_page.php?album_id=1572&image_id=8766
Regards,
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Lewm:
I've been looking for that RS-A1 white paper. Do you have a link to it?
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Sampsa,
Somewhere I have or had a hard copy. But I will also check my other computer to see if I have an e-copy. It's one of those almost laughable translations from the Japanese, but one can make sense of the main points. I see this problem with my son. He thinks and dreams in Japanese. When he speaks to a Japanese person, he does not stumble for the correct words. He is a real scholar in this area. But if you ask him to translate a document from Japanese to English, I can tell that there is effort required, and it takes time. In the RS-A1 white paper, you would see one claim that does not hold up; the paper states that "side force" (skating) is eliminated by the design, when of course it is not; it is only eliminated at the point of tangency to the groove.
Can you, in turn, point me to a review in which anyone compared two different versions of the Viv, so as to be able to say the 7-inch one was preferable? I did not find that review in my search.
Fleib, Can you explain to me how the RS-A1 tonearm reduces or eliminates torsional effects on the cantilever in the vertical plane? I guess you are referring to its other structural oddity, which is that the unipivot bearing is above the plane in which the headshell operates.
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Lewm: I recall seeing that white paper online, but have not been able to find it again. If you have a PDF, I'd appreciate it. The RS-A1 unipivot it supposed to be positioned so that the cantilever and tonearm are parallel or ideally on the same straight line. Since not all cartridges have the same angle for the cantilever (I think they range from ~15 to ~22), this will be an approximation. The limited design info I've found doesn't mention torsion, but speaks of "downforce": http://www.eifl.co.jp/index/export/rs-a1.htmlWhen we usually talk about skating force, we assume that the cantilever is tangent to the groove and pulled along this tangent (only true at those null points naturally). Since the resulting force is at an angle to the line going from the stylus to the pivot, a sideways force results. If the cantilever is not tangent to the groove, the friction force would still be tangent to the groove and thus straight arms would also have a sideways force proportional to the angle between the stylus and the groove tangent. I've seen reviews of the Viv Lab in The Ear, Stereo Times, and Audio Beat. All reviewed the 7" version and none of them complained about distortion. Audio Beat said they also had the 9" version, but just mentioned that the 7" and 9" sound different "and not in the ways you might predict". Also Audio Beat mentions that the order was the opposite you mentioned: The designer started with the very long version to reduce tracking distortion and then realized that the shorter ones sound better. Fleib: I'd appreciate links to those comparisons of Viv Lab versions too. |
Lewm, Sampsa, The only reason to elevate the pivot is to have the cantilever aimed there vertically. It's not beneficial for tracking like an underhung counterweight. That's the only plane where that happens on the Grado arm. The VE photo was supplied by Werner and the arm is said to sound great. There was no direct comparison of the three ViV arms. It was mentioned in Stereo Times that the shortest version reduced resonances. There was another review/comparison which I can not find now. It stated the 7" sounds better - for the same reason. Regards, |
It's amazing how far we can go with audiogon contributors, from old '7 inch records to the new '7 inch tonearms.
Well, i'm testing Lofgren alignment with good results on Victor UA-7045 with Victor X1 cartridge.
What is truly amazing with Victor X1 is my new 100k ohm resistors that completely change the sound of this cartridge. Hard to believe i'm listening to the same phono stage and the same cart i used before at 47k ohms.
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Chakster, You might consider listening to the Victor tonearm in Lofgren for several weeks. Then re-align for Stevenson (only assuming that the Victor UA7045 is designed for Stevenson), and listen for another few weeks. Then decide which you prefer. A few hours of listening to one alignment is not going to provide sufficient information, in my opinion.
Sampsa, I agree that when an underhung tonearm with zero headshell offset is operating anywhere on the LP surface such that the cantilever is not tangent to the groove, there is indeed a skating force. The only point on the LP surface where skating force is negated (zero) is that one point of tangency. But the apparent excellence of such tonearms, despite the large tracking angle errors that they can produce at the extremes, suggests to me that skating force created by the headshell offset angle necessitated to achieve any of the 3 major 2-point geometries, and maybe the common strategy for introducing anti-skate, may be in some way more pernicious than is the skating force due purely to lack of tangency. That's what interests me.
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@lewm Chakster, You might consider listening to the Victor tonearm in Lofgren for several weeks. Then re-align for Stevenson (only assuming that the Victor UA7045 is designed for Stevenson), and listen for another few weeks. Then decide which you prefer. A few hours of listening to one alignment is not going to provide sufficient information, in my opinion.
That's what i'm gonna do. I think i'm very well prepared for a long winter, it's start snowing and getting below zero degree. I will spend more time listening good music in the late evenings (using different carts and arms). That's the the plan. |
What is truly amazing with Victor X1 is my new 100k ohm resistors that completely change the sound of this cartridge. Hard to believe i’m listening to the same phono stage and the same cart i used before at 47k ohms. Hi Chakster, Subtle differences in damping; whether mechanical (from varying tracking force, anti-skate or application of damping fluid) or electrical (loading) can have a profound effect. Loading is about more than tuning the response peak although this is definitely important and dependent on your phono stage. Hi Lew - One reason I’m not inclined to take others’ experimental results at face value is because of small variances like what Chakster observed which tend to be overlooked. I’ve been guilty of this in the past as well. Setup parameters are another point of vulnerability. Since I’m in turntable development at the moment, one of my rigs goes unplayed for 2-3 weeks at a time. I find that when I fire it up, some fine tuning of the setup is necessary - specifically, parameters prone to be affected by suspension changes: azimuth, VTA and to a lesser extent, tracking force. Note that I don’t do anything until the cartridge has run for a few hours. IOW, this isn’t a result of the cartridge being "cold". Cartridges with line contact styli are more variable in this regard, although conicals are not exempt. I still want to ween you off that Feickert protractor ;-) It’s a good tool, but I don’t think you can achieve results repeatable enough to base your conclusions on. His software is great, but nothing in my experience has produced the precision and repeatability of an arc protractor and without this, I don’t think one can draw any meaningful conclusions. Cheers, Thom @ Galibier Design |
Thom, I haven't made any meaningful conclusions in years. Most of my conclusions are inconclusive. However, I do think that if we think we can set up a tonearm within less than an +/-0.5mm margin of error, we are kidding ourselves. By the way also, where did I say that I have any particular allegiance to the Feickert protractor? I also own a UNItractor from you know who in Germany. It's capable of a higher level of accuracy, but it's quite fussy to use. Thus I sometimes use the Feickert when push is coming to shove. I've got no beef with an arc protractor either.
Seems to me that a very slight error in implementing Lofgren A/B or Baerwald, or Stevenson, one that still results in two null points on the surface of the LP, is not going to make a huge difference in one's experience of the sound thus derived. I would be receptive to a contrary argument that is based on science.
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Chakster mentioned Feickert in OP. Great device based on the Dennison Soundtractor, gets excellent results as long as it's used properly. One thing often overlooked - an arc protractor is only accurate if your mounting distance is perfect (factory). If the factory is mounting an arm they didn't make, you might want to check it with a conventional protractor. **Seems to me that a very slight error in implementing Lofgren A/B or Baerwald, or Stevenson, one that still results in two null points on the surface of the LP, is not going to make a huge difference in one's experience of the sound thus derived.** +1 Although it depends on resultant nulls. Chakster, I bet you'll wind up with Loefgren alignment. Both nulls are within the recorded part of a 7". Error will be much less through most of song. Stevenson will be better at the end, but much worse up until there. |
fleibChakster
mentioned Feickert in OP. Great device based on the Dennison
Soundtractor, gets excellent results as long as it's used properly. Both of those protractors are flawed because they assume the cantilever is perfectly aligned within the cartridge, which is quite often not the case. That's why I prefer a mirrored protractor that actually aligns the cantilever.
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Dear @lewm : """
within less than an +/-0.5mm margin of error, """, that's almost the overhang diference between Löfgren B and Baerwald.
If we made an accurate overall cartridge/tonearm set up with either Löfgren or Baerwald it´s almost imposible that you or anay one else can detect differences in the quality level performance. Against Stevenson things could be diferent because higher set up differences in the main parameters and with higher distorions overall Stevenson.
In both cases we can make it more " easy " if we know what to look for in the tests listening process.
Now, all we need is the MINT LP that's a dedicated protractor for the TT/tonearm/cartridge and for only 100.00. Makes no sense to spend ( because is not an investment. ) any little dime over that cost because we can't achieve in true any single advantage but more " problems " for those expensive protractors you own or other people owns.
As a fact and I posted several times about no one of us should spend a single dime in protractors if the tonearm manufacturers takes its own/self critical responsability with their customers to delivery the tonearm with an ACCURATE and user friendly protractor !!!!!, it's his responsability not us one but we are the ones that already liberated them from that main manufaturer responsability.
Regards and enjoy the music,
R. |
Cleeds, My Dennison has alignment lines for the cantilever and I believe the others also have this. I also have a mirrored protractor and results are the same. Raul, An arc protractor is great if and only if mounting distance is in exact agreement with specification. Otherwise it's useless. The other protractors mentioned are based on where the pivot is actually located, not where it theoretically should be. Why spend $100 on a Mint? You can go to Conrad's site and generate one for free. |
Hi Raul,
I agree with you that a tonearm manufacturer should provide an alignment tool with their product. It’s in their best interest that the customer have the best chance of achieving a good setup.
Lew -
An arc protractor can get you to within .001" of tracing the arc - limited only by your patience. I had forgotten about Conrad’s site. I’ve never tested it against the ones I produce with my CAD software.
As noted above, an arc protractor is specific to a single tonearm effective length, and you now have a website that will generate a protractor for you. If your printer takes card stock paper, you’re all set.
I stopped following the "other" protractor thread when the manufacturer refused to reveal his chosen alignment. It’s his choice and I respect that, but at the same time it leaves me no way of validating the accuracy and REPEATABILITY of adjustments made using his tool.
Parenthetically, I might add that I’ve seen some very good setups done with a Feickert. My preference for an arc protractor is that it eliminates any and all ambiguity.
If you think about any tool which depends on your siting down your cantilever at one or two spots, you’ll realize that the manner in which an arc protractor magnifies pivot-spindle/overhang errors lends a dramatically higher level of precision and it does matter.
For sake of argument, let's assume you have a 0.5mm overhang error in your setup. If you rotated your arc protractor so that you can land the stylus on the inner (lead out) side of the arc, and and (without rotating the protractor) you swing the arm over the lead-in (outer) side of the arc the stylus will be several mm from the arc.
This is can be confusing when someone is first learning how to use an arc protractor because they think they may have a 2, 3, or 4 mm overhang error. Once you understand this "error magnification" however, it is a huge benefit in terms of enabling precision adjustments.
If forced to choose, I would opt for getting one tonearm/cart set up perfectly rather than taking a buckshot approach of multiple tonearms with suboptimal tools. Yes, I appreciate the fun of playing with multiple arms, but I’m a patient guy and would rather get one thing right than many things wrong.
Cheers,
Thom @ Galibier Design
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Thom, I am not sure what is your point in the last 3 paragraphs above, except to say that any protractor can give bad results if you don't know how to use it. And I don't think any one of us takes a "buckshot approach" deliberately. I am sure each of us is very meticulous, or at least feels that he has been as careful and precise as eyesight and lighting and the protractor make possible.
Wouldn't it be nice if we found out that underhung tonearms, which demand nowhere near the precision accorded to mounting overhung tonearms, were to become accepted as the superior sounding option?
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@fleib Chakster,
I bet you’ll wind up with Loefgren alignment. Both nulls are within the recorded part of a 7". Error will be much less through most of song. Stevenson will be better at the end, but much worse up until there. No, only one null point is on the recorded part of the 7" inch. As you know Feickert use 3 steps: 1) for overhang. 2) for offset at outer null point. 3) for offset at inner null point. Only Stevenson’s geometry is withing the 7" inch two times: First at step-1 (aka overhang), which is exactly the beggining of the recorded grooves (aka the beggining of the track, not the edge of the vinyl) on 7" inch, and step-3 (aka offset) on the inner null point which is exactly in the end of recorded music (not the edge of the label) on 7" inch vinyl. While the Baerwald and Lofgren are on the 7" inch ONLY at inner null point once. |
Chakster, sorry, I made a mistake, but so did you. None of the standard alignments have both nulls within the recorded part of a 7". Baerwald - 66.0 & 120.9mm Loefgren - 70.3 & 116.6mm Stevenson - 60.325 & 117.42mm 7" record recorded band - 57 (approx.) to 84.15mm These are all distances from center spindle. Only the inner null of each alignment will be within a 7". Loefgren will have least error at the beginning and Stevenson at the end. If you want to see the alignment error for each arm and with each alignment - you have to log in. http://www.vinylengine.com/tonearm_alignment_calculator_pro.php Regards, |
I have a Smartractor for a few days now and settle the Uni Din with good results. Today I changed the curve and trief the Loefgren B (DIN) and I clearly prefer the latter.
I listen mainly classical music and I find the flow of music more natural to my ears. Also the micro dynamics' the way the note begins has more snap.
tt is TW Acustic Raven AC wih Da Vinci arm and MC Anna cart. |
Fleib, In defense of the arc type protractor, the converse of your criticism of it is that if the P2S distance is not precisely correct, the arc type will tell you that, and you can fix the problem. Whereas the Dennesen and related types don't tell you that with as much precision and certainty. I have an original all-metal Dennesen, which I never use, since I greatly prefer both the Feickert and the UNItractor from Dertonearm. One reason I went away from it is the near impossibility of seeing either the tiny dimple into which the stylus must sit and the grid lines for aligning the cartridge body. They are SOOO faint. It was never easy to use, even in my yout', when I could see real good.
Barbapapa, After only one day, is it not a little bit premature to conclude that you will live forever more with the Lofgren B alignment? I myself am not given to love at first sight, which is why I ask. For one thing, had you auditioned the very same LPs using your old alignment, just prior to the latest re-alignment? Nice stuff, by the way.
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In defense of the arc type protractor, the converse of your criticism of it is that if the P2S distance is not precisely correct, the arc type will tell you that, and you can fix the problem.
If the tonearm is 1mm too far and you mount the cartridge 1mm forward so that the overhang is correct, can you really tell the difference between an arc with radius of 270mm vs. 271mm? The difference is going to be tiny. Notice that this is different from having the tonearm mounted right and having the overhang off by 1mm. The good news is that the effect on the tracking distortion is also very tiny, shifting the null points by less than 1mm if the tonearm is 1mm too far or too close but overhang is right: http://www.vinylengine.com/tonearm_alignment_calculator_pro.php?arm1=Arm+1&l1=ps&a1lv=271&am... |
Lew, I've been happy with a Dennesen for alignment for years. I find it so much faster, easier, and therefore more likely to be correct than 2-point arc protractors, such as the DB Systems I used previously.
However, I do utilize a good light and small hand held magnifier, then I have no problem seeing when the stylus tip is in the dimple and the cantilever properly aligned with the guide lines. Mine are not faint, just tiny. ;^)
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Lewn,
Maybe you are right by the way. I had the Unidin curve for 3 days but it still is a short time. Yesterday the Loefgren was used with the same records for a first comparo.
I admit I have been a bit impatient. Now I want to stay a few weeks with the Loefgren before trying the UniDin curve again and make a more definitive opinion.
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Dear @barbapapa : Overall Löfgren " A "/Baerwald and Löfgren " B " has lower distortion levels than the other alignment you mentioned. That alignment is not something " special ", it's only a manipulation of one of the input values in the alignment calculation formulas: the change was that instead to take either: IEC or DIN or JIS standards value for the most inner groove input it tooks 54 with no real overall improvement. As you, M.Fremer voted for Löfgren B too through his tests.
As I posted what any one of us need as a protractor is the MINT LP one, that's a dedicated protractor for the TT/tonearm we own. It's really accurated and for only 100.00-150.00.
IMHO no one needs more, is really useless stay trying any other protractor other than by curiosity. At the end what we music lovers want is listen MUSIC all the time and not testing 3-5 diferent kind of alignments. Again: useless.
Btw, @lewm posted: """
curve again and make a more definitive opinion. """.
You tested by 3 days and changed to Löfgren with the same LPs. IMHO you need no more. Your ears telling ( in this case ) what the numbers tell it too.
We can think that a short/brief time can't be enough and sometimes is true but when one person ( as you ) knows what to look for that times goes lower.
I don't need to many time to give my vote to Löfgren and Baerwald over Stevenson alignment: 2-3 hours can be more than enough. Why can I follow wasting more time? when what I want is to enjoy MUSIC. Makes no sense to me: makes sense to you?
Regards and enjoy the music,
R. |
Lewm, your defense of the arc seems valid, but the Dennesen types don't need perfect arm mounting distance. As long as you can sight the pivot intersection you can get a "correct" alignment provided you have enough headshell room. I always check with a conventional 2 point protractor. As long as the apparatus doesn't move, the alignment is good. Raul, What alignment does Mint use? (measure from center to first grid and compare to alignments above) Regards, |
Dear @fleib: The manufacturer choosed Baerwald ( I think???? because I 'm not an owner of it. ) and I don't know if he is willing to manufacture it Löfgren B. At the end Baerwald is excellent choice too.
Regards and enjoy the music,
R. |
@rauliruegas the MINT LP one, that's a dedicated protractor for the TT/tonearm we own. It's really accurated and for only 100.00-150.00. Or Dr.Feickert analog protractor (next generation) just for £137 new from analogue seduction in UK. The pound is weak and now it's just about $170 including shipping outside Europe. Superb build quality! |
