How much difference if the tonearm is mounted 5mm
Weather it will have any effect will depend on the length of the slots in the head portion when the cartridge is mounted. Their slotted for a reason. 5mm is only 2 tenths of an inch. Not much. Most slots are quite a bit longer that that so if using the recommended mounting distance would have placed the cartridge in the center or even forward of center of those slots, you just might not have a problem. Regards. |
As Griffithds said it will depend if you have enough room in the slots of the head shell to compensate for the distance lost. Also if you use an arc protractor it will need to be one that is for use at the same pivot to spindle distance as you have mounted your tonearm at. Otherwise it will be way off. What type of protractor are you going to use? |
I am probably restating what the others said above. It comes down to the protractor geometry in question, which as the others said, starts with spindle to pivot distance. It's just that simple. If your VPI came with a protractor, you will know immediately if you can mount the cartridge so that the stylus touches the precise point on the protractor that is the optimal overhang setting. If you can't dial in the overhang point of contact, tracking distortion will be increased. If you don't have a VPI protractor, you can buy one from VPI, or buy an adjustable protractor off eBay. I can't give you precise information on the added distortion effects, but suffice to say, each protractor geometry is set up to "optimize" minimal distortion results based on the approach and theory of the particular geometry in question. Good luck. |
Let me make it clear. When i mounted the arm as the manufacture suggested, 212mm STP, the cartridge could not reach the cross point on my Dr. Feickert NG Protractor (I extended the cartridge all the way out from the Pivot) it was 4mm short. Unless i have a longer head shell or i will have to mount the arm 4mm closer than spec. (5mm to be sure). If I mount it closer, and use the Protractor to align the cartridge, will the arm be performed as normal? Thanks to all who have responsed so far. Calvin |
If you mount the arm the 4mm closer I would suppose that it would be fine...(Harry said he or anyone else can not detect a bit off)...however, as for ME....I would want it absolutely correct. ....just a question....why would you want to exchange arms...VPI makes a very good arm...the 3D is wonderful. |
Assuming you can mount the arm where ever you want. With a Feickert protractor (own one myself) you can just mount the arm where you end up with the cartridge in the middle of the head shell slots, and still get the stylus in the middle of the cross marks on the protractor. This is where the arm should be mounted. The only draw back is the head shell offset may be a little off if it was designed to work with a 212 mm P2S distance. If this is the case do not aligning the cart offset to the head shell. Just align the cantilever (front to back) with the marks on the Feickert protractor, which should be done regardless. This would work for any arm you do not know the P2S distance on as long as you are using the Feickert protractor, or one that is of the same design. Regardless I would contact the manufacture and try to get a replacement if the arm is not to spec, because this would make the arm impossible to resell if it is off. Someone else may not have the flexibility to mount the arm at a different distance than what is specified. |
Good morning, Thanks to all of you who have answered to give advises in this matter. Yesterday, I mounted the arm 5mm shorter than manufactor reccomedation. The result was terific. I will run it for a few days to breaking in and will report back. In the mean time, does anyone know is there exists any head shell which has the mounting distance further than normal? All I can find is the Ortofon LH 9000 and the zyx headshell. I an leaning to the zyx but it is too expensive (700 retailed). How effective of a good design headshell soundwise? Thanks Calvin |
The ''Zupreme'' sold by LP/Gear has the slots quite a bit forward. This head shell is Magnesium with the screw for azimuth adjustment. Litz leads and are the same head shell as the Sumiko's. Their just not branded as such and sell for $50 instead of the $90 that Sumiko's get! In my opinion, the best head shell available! Regards, |
Dear Dang, In some responses, it seems the responder is confusing pivot to stylus tip distance with spindle to pivot distance. If the spec for your tonearm is 212mm, spindle to pivot (P2S or PTS), then it is folly to tolerate a 5mm error in that parameter, as CLeeds and maybe some others already said. If you are using a Dr. Feickert protractor, and if you observed a big problem when you set P2S to 212mm, then in some way you may be using the protractor incorrectly. I use one, and one of its best features is the capacity to set up P2S before alignment of the cartridge body, because the arm that extends from spindle to pivot point, on the Feickert, is calibrated in mm. Once one has done that, then aligning the cartridge is the veritable piece of cake. I'm not sure what your problem is, from this distance. Perhaps you are mislocating the pivot point on your tonearm. If the manufacturer specifies a 212mm P2S distance, then the headshell should not be 4mm out of whack. Only other possibility I can think of is if the tonearm is set up for Stevenson alignment, not the standard for the Feickert. |
Hi Lewn, Your response totally makes sense to me. Here is what had happended. when i mounted the tonearm 212mm S2P the cartridge could not reach the crossmark on the Dr. Feickert Protractor, it seams like the slots are too short. Two days ago, I mounted it at 207mm, the cartridge can touch the crossmark now, but the offset angle is off at about 20 degree to get allignment correctly. As of now, all i can think of is the arm problem since I have used the Protractor before with the Vpi jmw and the Triplanar vii u2 with no problem at all. Please give me your opinion. Thanks, and I used Baerwald, i will try Stevenson to see if it is any better. Calvin |
Lewn, The problem with 'trusting' the given dimensions for spindle to pivot is that it is expected that everything else will just automatically falls into place (dimensionally). Well, that isn't always the case. What you are trying to accomplish is for the stylus tip to correctly trace a given curve line. BTW: All tone arms with a cartridge mounted will make a perfect circle it they were being used to draw with. You want the stylus tip to follow a section of that circle (part of that curve), in which the record is going to be placed on. The setting up of the spindle to pivot distance only ''assumes'' that the stylus tip is then going to follow this curve. It just might if you only use the head shell that was or is provided by the tone arm manufacture. That is because he has provided those head shell ''slots'' to be in a position that would allow you to mount a cartridge so that it will follow that curve. Use some other head shell and those slots might be in the wrong place. I use the Mint LP Tracker or sometimes referred to as the Best Tracker as my cartridge set-up device. If you were to 'hold' that stylus tip onto that curve line, and you had the cartridge mounted in a head shell with very long slots, could you not move that pivot point in or our (closer to or farther away from the spindle), without moving that stylus tip? Yes,moving it out 6 feet would change the curve but we are not talking feet. Not even inches. We are talking 5 milimeters. The change in the curve would be even smaller that what the difference is between the Stevenson and the Baerwald. Not to even mention all the other variable alignment protractors that are out there! I find it more important to decide what head shells you wish to use, and then set up for it. Not the other way around and have your hands tied sort of to speak, being forced to use what ever head shell (slot position), that the manufacture decided upon. I like Magnesium for head shell material, and I like to have adjustable azimuth. Most tone arms do not provide this Azimuth adjustment feature. My Graham arm does, but neither my JVC 7045 or my Lustre GST-801 do. I do not want to shim head shells, so I have chosen the Sumiko's, or cheaper yet, the 'Zupremes'. There is no industry standard as to where these head shell ''slots'' are suppose to be. This is sad but true. The JVC 7045 tone arm came with its own head shell. I marked a dummy arm board (made out of plywood), per the spindle to pivot dimensions given and drilled it. I then mounted the arm, the provided JVC head shell with a cartridge installed. It followed the Mint tracker curve perfectly. I then remove the JVC head shell and mounted a head shell with a cartridge that was not a JVC head shell only to discover that I could not get the cartridge to slide far enough back in the slots to trace this curve. I tried several other brands of head shells that I have with cartridges mounted in them and none of them would allow me to position the cartridge so that it would trace that curve line. So where is the problem? Is it the spindle to pivot distance dimension? Well, if you only use the supplied head shell from JVC, then the answer is 'No'. But if you wish to use head shells supplied by other manufacturer's then the answer is 'Yes' . That spindle to pivot dimension is wrong. I did finally drill my arm board but I didn't use the supplied dimension given on the drilling templet. I drilled the hole so that my cartridges sit in the center of the slots when they are mounted in one of these Sumiko's. The stylus tip traced that Mint Tracker curve line perfectly. I don't know nor do I care what the spindle to pivot dimension is. I only care that it traces the curve correctly. Regards, |
Lewm, I should also mention that the supplied head shell from JVC also is usable after my drilling. But instead of the cartridge being mounted in the center of their slots, the cartridge is now mounted near the forward most location of their slots. All other brands of head shells allow the cartridges to be mounted some where around the center. Some more forward, some more towards the rear. But all will follow the Mint Tracker curve perfectly. Regards, |
Dear Dangcaonguyen: """
I mounted the arm 5mm shorter than manufactor reccomedation. The result was terific. """ IMHO what it's terrific down there are only " terrible " and high distortions not real music information. Many years ago Löfgren makes a huge research and found out what after him was the flagship of a tonearm alingment ( you can search google for those white papers to understand the meaning/foundations of the theory. ) where vintage and today tonearms has each one tonearm specific alignment parameters. What define those critic parameters ( overhang and offset angle ) is the tonearm pivot/bearing to spindle distance where for each PTS distance exist one and only one offset angle and overhang. Each time that STP distance change these two parameters change to aling correctly the cartridge in the tonearm. Look, the difference between the Löfgren and Baerwald alignments with the same PTS distance is less than 0.6mm in the overhang where the offset angle stay the same in both alignments proposals. In this example the whole tracking error ( pivot tonearms. ) is different all over the LP recorded surface. Here you are talking of 5mm!! with out changing the offset angle!!!, so the tracking error goes up in exponential way"""" and that's what you are hearing. Those gentlemans that gave you the advise to change the cartridge position through slots do not understand yet from where come those parameters values ( equations on the white papers. ) on overhang and offset angle. Now, here you can read all referent to mount VPI different tonearms an you have to mount any cartridge on them through the VPI dedicated protractor and if you are in doubt then contact directly to VPI: http://www.vinylengine.com/vpi-tonearm-geometry.shtml and here you can read about calculators when you need a different PTS distance, overhang or offset angle: http://www.vinylengine.com/tonearm_alignment_calculator_pro.php or you can downland this calculator that gives you all you need to know about and know how distortions goes with changes in any tonearm/alignment parameter or alignment kind: http://www.enjoythemusic.com/freestuff/BaerwaldLofgren88.xls Regards and enjoy the music, R. I |
I'm sorry Raul, but I do not listen to 'white papers' so I do not know what they sound like. I listen to records and know what I 'hear'! What you state about there only being one correct number for overhang and offset angle of any particular tone arm length is true. But that doesn't meant that the person who came up with those numbers on my JVC templet are the correct ones! Nor does that meant that the numbers for set-up in the tone arm in this thread are the correct numbers because they are ''only'' numbers printed on a form. Nothing more, nothing less! The proof is in how it traces after set-up. Not how it measures in regards to some printed number on a form! The arm in question was not actually measured so how do we know what its 'overhang and offset angle' should be? You 'assume' that its length is what is stated on the templet. You 'assume' that the dimensions stated on the templet is correct. You 'assume' that to drill this hole for the arm to mount into will be correct. Sounds to me like you are ''assuming'' far to much and not doing enough 'actual measuring! After drilling, it either tracks that Mint Tracker correctly, or it doesn't. That is all, and nothing more. If to do so, some other number had to be used to drill the mounting hole distance from the spindle for the arm, so be it. The point is to track the curve line. Not ''what does it measure''? Regards, |
Hi Rauliruegas, i mounted the tonearm 5mm closer (pivot to spindle, not pivot to stylus), and used the Feickert protractor to mount the cartridge. Therefore in theory, if I understood it correctly and if we could trust the Feickert tractor, the cartridge was mounted in the right geometry figured out by the maker of the protractor. Am I right? The only thing which is bothering me is, although the arm cartridge combnation peformed correctly, it will not get out all of its potential which the designer put onto the arm. Also, the offset angle is off at arround 20 degree make me worry for the pivot bearing. I hope it makes sense. Thanks, Calvin |
First of all, Hola', Raul! Second, Dang, are you saying that after setting P2S at 207mm (which is quite short for even a 9-inch tonearm), your cartridge could be perfectly aligned with each of the two grids on the Feickert protractor, including the front to back alignment of the cartridge body? Your tonearm is totally unfamiliar to me; is it "vintage" or a brand new product? If vintage, the tonearm may have been designed for Stevenson alignment, especially if it was made in Japan. The Feickert is designed for accurate alignment to the Baerwald standard, which is very different from Stevenson. (Which by the way also means that you should not use the Feickert if you want to try Stevenson alignment.) I cannot recall whether the Stevenson is "shorter" in pivot to stylus tip distance than Baerwald or Lofgren, or whether it's the other way around, but possibly this is why your alignment appears to work, but you would have had to twist the cartridge body with respect to the headshell to make it work, i.e., to achieve the proper offset angle so the cartridge body aligns with the grids on the Feickert. Is that the case? If so, maybe another mystery is solved. Third, DSGriffith, I don't really follow your argument, but I have to agree with Raul, who after all is agreeing with me. On the other hand, I take your point that aftermarket headshells or swapping OEM headshells between two different tonearms may complicate the alignment problem. For a given geometry (Baerwald, Lofgren, or Stevenson) with a given tonearm, theory predicts there one and only one "most" accurate alignment (defined as that which gives minimal tracking angle error on average across the surface of an LP). (I'm aware that Baerwald is identical to one of the two Lofgren methods, A or B. Can't remember which.) I am not one who believes you need to be within a micron of "accurate", but 5mm seems a huge error. There are cases about which I have read where persons in the field have come to disagree with the manufacturer of this or that tonearm on what is really the best P2S distance, etc, for a given tonearm. This is true for the FR64; FR says 230mm, gurus say 231.5mm. |
Hi Lewm My main point is not to dispute overhang dimensions but to dispute the assumption that because a templet says a arm is a certain length then the arm that you are mounting "IS" that length. Measure it and then determine what the overhang is suppose to be for the arm that you are mounting. Not some factory manufactured arm that has been made from tooling that has +/- tolerances built into the assembly tools and possibly put together by some guy on Monday morning with a hangover! BTW: I also agree with what Raul and you have stated. But text book definitions are not what the question here was. I think the arm in question does not measure in length for what the overhang dimension given is suppose to measure. This particular arm just might sound better positioned at a location other than what is printed on a templet. Regards, |
Dear Dang: So, you are saying that PTS distance is 207. Nothing wrong with that if the offset angle and overhang belongs to that PTS distance. You can see it here: http://www.vinylengine.com/tonearm_alignment_calculator_pro.php?arm1=Arm+1&l1=ps&a1lv=207&am... as you can read on that chart the arm1 almost follow the Löfgren alignment so it's right, no problem at all. Now, looks like the cartridge overhang is correct because even your protractor points and only you have to be sure that the cartridge offset angle has the same value in that calculator chart to have the levels of traking error/distortions for that geometry alignment. The distortion levels beteween a tonearm mounted at 207 or 212 mm from the pivot are almost negligible if in both cases the overhang and offset angle are in the right position. Don't worry what the tonearm manufacturer put on his tonearm specs because we can change the effective lenght of that tonearm if and only if we are sure thet the overhang and offset angle is right on for that geometry alignment choosed. Now, if you are sure of all those critical parameters then your " terrifc " sound posted is just true musical information with distortions at minimum for that geometry alignment. Regards and enjoy the music, R. |
Dear Griffit: "
I listen to records and know what I 'hear'! ", yes but what you don't know is the distortion levels generated for your choosed alignment till you use " white papers "/calculator of those white papers equations. Tonearm/cartridge alignment is just geometry not rocket science but even that you need to work with " numbers " where " subjectivity " is not enough. Of course that if you don't care about distortions levels then you can do whatever you want. Regards and enjoy the music, R. |
Raul, read the opening post. A tone arm was bought. Should he drill the mounting hole at the given dimensions per the manual? You say yes. Why? Because the manual says so? Sorry but mistakes often get made on drawings. I'm a Aerospace engineer and I have correct hundreds. Who said that the arm in question actually measured what the manual says they all are expected to measure? To drill a hole in your arm board because some stranger says that is where most of the arms he has manufactured should be located is just plain wrong! That arm should be measured. S2P determined. Then drilled. It is not rocket science. It is just plain common sense. We are not talking text book geometry here. We are talking about one particular tone arm. Regards, |
ds, Have you really observed such errors? I am putting myself in your shoes. In my thought experiment, I have a new tonearm, and the manual says to mount it so as to achieve a pivot to spindle distance of 215mm (for example). What measurement would I make of my sample of said tonearm in order to know that following this instruction would be a mistake? I guess that could be distance from pivot to center of headshell slots, for one example. But manufacturers don't often even supply that spec. So how did you know that you had a "bad" sample of any particular tonearm? I respect that your training and life experience may have equipped you to detect and solve such problems better than I. In my imagination, badly made samples would be more likely to have out of spec bearing friction, much more likely than to be significantly (could define as +/-0.5mm???) longer or shorter than specification. As I noted above, there is also the case where thorough analysis of the geometry might lead one to prefer a different P2S for a given tonearm from that which is recommended, but that still assumes all of the samples of that tonearm are alike. |
Dear Dangcao: Sure that Lewm ( Hola! ) will give you a precise answer about your protractor. In the mindtime you have to know that the Stevenson geometry alignment is the worst one of the 3 you mentioned because is the one that gives you the higher distortions/errors all over the LP recorded area but the last few indide mm. and I'm sure that other You can read it and see it through the link I posted and gave to you. I hope this time you really read it, is very important to understand the why's on this critical alignment issue. http://www.vinylengine.com/tonearm_alignment_calculator_pro.php?arm1=Arm+1&l1=ps&a1lv=207&am... Regards and enjoy the music, R. |
Lewm, If you are given a spindle to pivot distance mount point of 215mm, then there must be a arm length that was used by the person who approved that 215mm position. Measure your arm and verify that it measures what is assumed to be its length. If it doesn't measure that length, and I have one that didn't, then that mounting hole you are about to drill (using that 215mm dimension), is going to be in the wrong place. My JVC UA 7045 tone arm is the arm that has convinced me to do the critical check and not just 'blindly trust' those printed templets. On the templet for the JVC 7045, the spindle to pivot dimension is 130mm. The templet shows that the head shell arm lift (which btw, attaches to the cartridge), would then be in the center of the slots. I drilled my dummy plywood armboard as stated. 130 mm from center of spindle to pivot point. The cartridge when mounted in the Technics head shell, when set-up using the Mint Tracker curve device sat in the most forward locating of the slots. This is and of itself would not be a problem if I only used one cartridge and had only this one head shell. But I own 80+ cartridges. All mounted on various head shells. What I discovered is that this particular Technics head shell has its slots are not only longer, but are also positioned 50mm farther to the rear than any other head shell I own. Its most forward cartridge location position is to the back side of some of my other head shells and beyond the slots on most others. I even have other Technics head shells who's slots do not even come close to this original head shell that came with this tone arm. Now ask your self. What is it that you want to do? If you are using a curve checking device to set up cartridges with, then is that not what your goal is? To set the cartridge so that it traces that curve. I wanted to know why no other head shell will work with this arm except the one provided by Technics if that is, I drilled my arm board where I am being told to drill my arm board via their templet. What I discovered is that my arm does not measure in length what it states it to be on that templet. It is slightly long. How long? By close to 5mm. I thought about removing the head shell collar and machining the end of the arm tube to shorten it by this 5mm. (The company I worked for has a rather large machine shop so I could have pulled in a favor and had this done for free). But why take that route. Why chop up the arm when it was obviously the numbers on that templet were not representative of what my arm measured. Why not just take the arms current measurements and reconfigure that spindle to pivot distance so the the hole I drilled actually is where is should be in reference to my actual arm length. Not where I am being told to drill it. My arm hole currently measures 135mm from spindle to pivot. 5mm more from the spindle that stated on the templet. All my head shells, now are usable. Even that original Technics allows the cartridgde to be mounted closer to what is depicted on the templet. When I state ''are usable'', I am referring to setting them up correctly with the use of the Mint Tracker. If the stylus tip deviates from that curve line anywhere on that line, whether it be near the spindle or near the records edge, then it is not set up correctly. I have a picture taken of the original Technics head shell sitting along side a Sumiko head shell. Give me an email address and I will gladly send it to you so that you can see for your self. Once you see it, then picture in your mind if a cartridge was mounted in the center of the slots on the Technics, where would it be in the Sumiko which is sitting right along the side of it. Now put yourself in my place at the time I was trying to figure out where in the hell to drill this hole. At that moment in time, where did the actual error lay? Was it the arm length? It might be correct pertaining to the drawings being used to actually manufacture the arm. Then Is it the drilling templet that is wrong? Would you have just blindly gone ahead and drilled that S2P distance hole as stated by the experts who included this templet with the arm? Well there is an error here somewhere and it certainly wasn't going to be the hole that ''I'' drilled! Any other questions? Just ask. BTW: You have resurfaced memories of this experience that I had sincerely tried to forget! (gran) Regards, |
Dear Dang, I have not mounted a cartridge in several months, but it seems to me that my Feickert protractor, which is one of the older versions (assuming there are newer versions, which does appear to be the case), is designed for only one geometry, which I think is Baerwald. Perhaps yours is different. If yours has a Stevenson option, you might try it if only to verify that your tonearm was designed with Stevenson in mind. In which case, the headshell and the cartridge body will align with each other only for the Stevenson option. This does not mean that you must use Stevenson. It only means that you will be twisting the cartridge body with respect to the long axis of the headshell in order to attain any other geometry, and probably also needing to move the cartridge screws to the ends of the slots in the headshell to get Lofgren or Baerwald. If you care to do it, you could try the recommended 212mm with Stevenson parameters. If that gives you an alignment where the cartridge lines up with the headshell and the screws mount comfortably, I think we've explained your findings. If you set up a "Stevenson" tonearm according to Lofgren or Baerwald, the recommended P2S is going to seem too long and the screws will be out at the end of their allotted travel, or beyond, and the cartridge will be "twisted". ds, I haven't the time right now to digest all of what you wrote, but it seems in the first instance that you are talking about not trusting the template supplied with and for the tonearm. I fully agree that this can be problematic. I've had bad experiences in that regard myself. |
Lwem, Who exactly are you to trust if you have bought a tone arm in regards to setting it up? 'dangcaoguyen', the gentleman who initiated this thread, provided the information given to him and and asked if he could move the mounting hole over 5 mm? Then gave reasons why when mounted using the supplied set-up dimensions, His Quote "the cartridge could not reach the cross point on my Dr. Feickert NG Protractor (I extended the cartridge all the way out from the Pivot) it was 4mm short. Unless i have a longer head shell or i will have to mount the arm 4mm closer than spec. (5mm to be sure)". Sounds rather familiar to me!!!! Once you digest my thread, it should also sound familiar to you. I addressed his question. I didn't expect others to give a destitation of text book arm geometry! He wasn't asking for a schooling in arm design theory but just a simple answer to what he discovered. His suggestions and discoveries, mirror mine! Regards, |
Dear Griffit: "
He wasn't asking for a schooling in arm design theory but just a simple answer to what he discovered " I totally agree but thing's are that I always post trying that in any audio subject where I have experiences not only say: " yes or no " but trying to learn more on that subject and that other people can do it. We all will improve our audio knowledge level if we all understand where everything comes down, where is " generated ". I'm sure that some of the gentlemans here and viewers of the thread already learned " something " on each single post in the thread and this ( for me ) is the right target in any audio forum. In my case your contributions here do not gave any new " light " but through this thread I learned that the Dangcao protractor is for at least 3 different geometry alignments where the Lewm one ( same manufacturer. ) is only for Baerwald. With all respect my sugestion for you is that instead to " blame " my posts will be better if you ignore it. How about?, sounds good: right? Regards and enjoy the music, R. |
Raul, Quote: Dear Dangcaonguyen: """ I mounted the arm 5mm shorter than manufactor reccomedation. The result was terific. """ IMHO what it's terrific down there are only " terrible " and high distortions not real music information. End Quote: This is your idea of helpful? To criticize by questioning his findings after his deviation from the printed hole location. Did you actually hear what his system sounded like? It his system. If it sounds terrific to him, then I believe him. But to tell him that that what he is really hearing is ''terrible'' and high distortions not real music information is plain B/S! Regards, |
Dear Dangcao: Japanese " loves " that S geometry with foundation in that the climax , normally in classical music, happens at the end of a LP side and those clemaxes are recorded at higher velocity and at the end/inside part of the LP the forces are harder for the stylus/cartridge to track it. So, the S geometry " helps " for the " normal " distortions ( other than the geometry alignment ) be at " minimum in that part of the recorded area but we have to pay for it because only in that inside part ( few mm. ) distortions are lower but in all the LP area just from the begin the distortions are way higher tahn in other kind of geometry alignments. Several of the vintage topnearm designs came from Japan. At the " end of the day " in almost any tonearm you can make the tonearm/cartridge set up with the alignment of your choice. I don't know yet one tonearm that accept one and only one geometry alignment kind. Regards and enjoy the music, R. |
Dear Stringreen: Some tonearms comes ready for the offset angle if you mount it according the manufacturer advise but if you want to change it then sometimes you need to twuist the cartridge to have the right offset angle. MANY TIMES YOU HAVE TO DO IT BECAUSE YOU NEED THAT THE CARTRIDGE CANTILEVER BE STRAIGHT TO THE PROTRACTOR LINES WHERE SEVERAL TIMES THE CARTRIDGE CANTILEVER IS A LITTLE OFF POSITION WHEN BUILDED BY THE CARTRIDGE MANUFACTURER. The tonearm/cartridge set up is a extremly critical set up where there is no " land " to even minimum errors/mistakes because fraction of mm. change for the worst the distortions levels and where those distortions happen. I posted here that for the same cartridge/tonearm set up the difference between Löfgren and Baerwald alignment is less tha0.5mm on overhang staying the offset angle almost the same and if you go to the links I posted you will see in the charts how changes the distortions for both aslignments. This kind set up permits CERO tolerances if we want minimum distortions. CERO tolerances is almost imposible to achieve so we have to have extremly care to make this kind of set up everywhere in the " circuit of the set up ". Regards and enjoy the music, R. |
ebm, You are correct if that is what the final setup actually measures. That the position of his actual arm is 5mm out of the correct spindel to pivot dimensions for the length of his actual arm. 5mm off is 5mm off! But what is implied from the beginning of this thread is that there is 5mm difference between the the information given to make this setup and what the actually set became! One of the two options is right and the other was wrong. Is it the final position of the arm that is wrong? The owner of the arm says it sound terrific in its current location. This location is 5mm off from what was stated for it to be positioned. Because 'crappy sound' has not become the outcome of him moving the mounting hole over by this 5mm, then I would say that the spindle to pivot distance number he has been given was incorrect. His is not incorrect to have set up his arm correctly, only incorrect for not using the numbers supplied. If 'not crappy sound' is what his goal was, then what he did was correct. If following supplied dimensions was his goal, the he was wrong. I would prefer the 'not crappy sound' outcome over the following of supplied dimensions! regards, |
Dear EBM: You can read some information of what I posted. Now, if in that tonearm set up: overhang, offset angle and pivot to TT center spindle distance belongs exactly to a determinated geometry alignment like Löfgren, Baerwald or whatever then that " crappy " sound will not appears. In one of my links ( VE calculator. ) I made a comparison between different PTS distance in specific for those 5 mm. The calculator gave us the values for those 3 parameters I name it ( in both cases. ) and gave us the diagram where we can see the differences in distortion levels and if I remember when all those 3 mparameters are right the distoriton levels are almost the same. So, IMHO no crappy sound. Regards and enjoy the music, R. |
