S-shaped arm vs linear tracker vs straight arm?

Discussion in 'Turntables' started by Anubis, Jun 3, 2010.

  1. Anubis

    Anubis Super Member

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    I was browsing some TTs today out of curiosity and I wonder:
    What, if any are the advantages and disadvantages of S-shaped arm tables of straight arm tables and linear tracking tables over S-shaped arm and straight arm tables?

    Thanks everyone
     
  2. BrocLuno

    BrocLuno Lunatic Member

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    Linears have no tracking error. Most S arms and a few straight arms have user replaceable headshells that allow one to have a few cartridges ready to go for that table. Some straight arms are very nice, but some are short for DJ work and have very high tracking error rates. They must use a conical stylus.

    To take this conversation any further we need to know which specific arm you are interested in?
     
  3. thedelihaus

    thedelihaus Nocturnal transmissions

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    Linear trackers have been some of the best sounding tables I've heard- especially the Mitsubishi LT-30.

    Straight arm and S arm differences are not as severe, and some would even say nominal.

    Any of the above, designed well, will offer great performance.


    The benefit of a traditional S or straight arm is less complexity.
     
  4. Nat

    Nat AK Subscriber Subscriber

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    Obviously a straight arm can be lower mass than an S arm of the same length and robustness. But its easier to mount a headshell mount directly into the S arm -- you can do it at an angle with a straight arm, but then you have a more or less massy part right where mass has the most effect, which sort of defeats the point of a straight low mass arm. And the low mass interchangeable headshells on straight arms tend to be a thumbscrew, which may not be all that rigid.
    Meanwhile, the curvature in the S arm actually helps damp out resonances. Though the arm may not be balanced right to left with different mass cartridges, so some manufacturers as lateral weights, which suddenly introduce another set of resonances...
    So there is something to be said for both types -- straight arms probably maximize their virtues with fixed headshells, and curved arms probably are more justified if their purpose is to allow interchangeable headshells.
    When straight arms came in, their advertised benefit was low mass -- now that high compliance cartridges are less popular, that may not matter as much.
    Linear arms often are lower mass than pivoted arms, and can allow less tracking distortion, but often its at the expense of lack of rigidity, complexity, and gumming up lubricants. And often they are pretty expensive. So there too, there is a set of tradeoffs.
     
  5. Anubis

    Anubis Super Member

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    Thanks everyone, this is the info I was looking for. I don't have any particular arm or TT in mind right now, I was just looking at some on the internet and saw the three different types and that question entered my mind. (I do have a Sony PS-LX520 TT, it is a linear tracker. Although I think it's not great quality, plays good though. However, I have nothing to compare it to. I think I paid about $90 or $100 for it new back in the day.
     
  6. fastbike

    fastbike Well-Known Member

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    Broc, It reads that you think straight arms require conical stylii. You didn't really mean this did you? Straight arms aren't found on only those goofy DJ tables you know. The DJ arms have high tracking errors true.

    Straight arms are typically lower mass than S arms.

     
  7. JohnVF

    JohnVF Lunatic Member

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    S-shaped, straight or Linear is less important than how well each is executed within the whole design of the turntable. There are excellent examples of all (as well as turntables with designs that would allow you to mount any of the three).

    Not all straight arms are DJ arms :) (I know that's not what you said):

    http://www.sme.ltd.uk/content/Pickup-arms-1308.shtml
     
    Last edited: Jun 3, 2010
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  8. BrocLuno

    BrocLuno Lunatic Member

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    As I said some are very nice (read audiophile), but some are DJ beasts with exceptionally bad tracking errors. The short (think DJ) arms need conicals to work around the reduced overhang and short swing radius.

    The longer straight audiophile arms can handle any cartridge - but mostly one at a time needing physical dismount (think un-bolt) to change. Some nice straight arms accept proprietary headshells and you can have more than one ready to go.

    As I said, need to know which arm we are talking about?
     
  9. Nat

    Nat AK Subscriber Subscriber

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    There may be some confusion about what is meant by straight. In any scenario other than backscratching, a straight arm is a straight arm tube with an offset cartridge. Only DJs who backscratch have any business using a pivoted straight arm with the cartridge in line with the arm -- the tracking error is horrendous, and, as BrocLuno says, they need to be used with conical stylii which a less sensitive to misalignment in the groove (and can take higher tracking forces which also helps with backscratching).
    This shouldn't be taken as a condemnation of spherical stylii, which can be very good, though there is a limit to their high frequency extension -- I never felt the Decca I used to have suffered from having a spherical stylus, nor do the legion of Denon 103 users.
     
  10. barkerd

    barkerd Super Member

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    we must compare apples to apples : is this a "what is best , given NO financial constraints on the design and it's manufacture"

    or is it " in general , with higher consumer grade TT's and tonearms , which has generally been shown to be the better performing design?"

    Personally, I like the advantages a straight arm delivers, and I would say that this fact is partially born out when you look at the massive (forgive the pun) numbers of "S" arms 'back in the day , compared to now. Also look at the manufactures, back then , that stuck to their guns and said "straight is better" , even when the most common thing to do was have an "S" shaped arm .......
     
  11. Nat

    Nat AK Subscriber Subscriber

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    I'm trying to think of who made straight arms in the 60s and early 70s when S and J arms were omnipresent, and the only obvious candidates are Garrard, Dual, Miracord and BSR -- all changers, and possibly because an S arm that had to clear the stack of records might take up too much space.
    You did have a few specialists -- Grado, Win, Castagna (which sure seemed like the Win's predecessor), ADC, and Decca (and there are more), but none big sellers. Almost all manufacturers went with the SME/japanese headshell and that drove them to S or J shaped arms in order to have a strong mounting system.
    It was when high compliance cartridges came into their prime that the extra mass of the curved arms became an issue, and then you started seeing arms like the Grace 707. At the same time, and for somewhat similar reasons, unipivots grew in popularity, and they are much easier to deal with with straight arms, so you got the Decca and Mayware, then the Hadcock et al.
     
  12. guiller

    guiller Toscaninichus Australis

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    I don't know if Thorens arm (TP13) tonearm for the Thorens TD-150 turntable (1965) qualifies as "straight", but it seems to me not to be S -shaped:

    [​IMG]

    Something similar could be said of the TD-125 with TP-25 tonearm (1968).

    [​IMG]

    Something similiar along these lines could be said of the subsequent tonearms for the TD-125 MK 2 and TD-126, but this last model was introduced in 1974. Please, correct me if the pictures show the incorrect tonearms.

    Ref: http://www.theanalogdept.com/thorens_history.htm
     
  13. Nat

    Nat AK Subscriber Subscriber

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    Those would be classified as J shaped (headshell is straight), whereas the later arm on the 125 and 160 were straight, with an angled headshell.
     
  14. Pio1980

    Pio1980 AK Member Subscriber

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    Curved arms would take an SME/JIS T-4 interchangable headshell, straight arms with interchangable headpieces had a variety of standards tho' lo-mass interchangable-head arms took a standard plug-in with the necessary offset that the curved arm provided designed in, like this;
    [​IMG]

    0.7 mil conical tips cannot properly trace the higher velocity modulation, particularly toward the inside of the disc where relative linear speed is much less rendering the modulation denser. A tip with the requisite 0.6-0.7 width and a narrower front-to-back contact patch profile will have better tracing accuracy but will demand more precise set-up for proper function. The conical tip is more forgiving of imprecise set-up and record standard variances.
     
    Last edited: Jun 4, 2010
  15. benb

    benb Well-Known Member

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    To anyone who knows basic mechanics this seems like a silly thing (because it IS), but I have the impression that decades ago people thought the S-shaped arm had less tracking error than a straight arm (with the same pivot-to-stylus length). I seem to recall one guy in college who thought that. Was this ever used as a selling point?
     
  16. Nat

    Nat AK Subscriber Subscriber

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    Flim flam has always been a part of audio advertising, so I don't doubt that many people have made this argument (and, no doubt, the reverse argument also). I think that people either actually hear differently, or interpret what they are hearing differently enough that its possible to argue both sides of an issue honestly, if the issue is defined narrowly.
    A good example is the issue immediately preceeding of spherical stylii -- its objectively correct, I think, that a .7 mm stylus can't trace the highest frequencies without distortion, but set against that the enthusiasm of many audiophiles for the Denon 103, the Decca London, and various other cartridges with such stylii. These listeners aren't cheap -- MC cartridges even with spherical stylii cost more than most MMs,even of the highest quality. So what is it that they are so enamored of? Its got to be that hf extension actually matters less to these people than the purity or accuracy of what is there, or that some peak in the lower hf masks the roll of. But its fair to suppose that anyone willing to pony up the cost of a Denon actually has spent enough on their system that they could tell if it was just peaking.
    So maybe hf extension isn't the summa qua non, at least for some people.
     
  17. Brett a

    Brett a ~◦●○o0o○●◦~ Moderator

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  18. Jeff Levy

    Jeff Levy Member

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    I have three tables and plane on keeping only two. And I am no tech guy by no means :) I have a Sony PS-LX520 linear TT w/ a simple AT cart, and really love the sound and ease of use. Low mass arm for sure. As long as you clean the rear bar and relube it, it should float smooth forever. That is technically a straight arm that produces sound from a critical point... the same spot the masters were cut from and they keep distortion way and alignment great. Auto silence circuitry makes this table really quite too.Hooked up to my mid 80's ONKYO or TECHNICS receiver and FISHER huge floor speakers, I get quite an awesome sound. Surprises me actually. OK the other two.

    My Harman Kardon T-25 is a straight arm, (low mass) table. 1.1 pound base, not the huge 4 pound like on the T-65. Still impressive. Simple and beautiful. Sounds incredible. Quiet and faithful reproduction. I have that hooked up to a Telefunken TR-400 DC series receiver. Monster unit. Great phono preamp - great everything. Its a beast. I have this hooked up to PSB Alpha1 bookshelf speakers and it crisp and clean.

    My third table has a J-arm. Just picked it up so I cannot say much about it yet. AT cart (all 3 have AT carts).
    Its a pretty rare table and I got it for free basically still in the box, with the styrofoam etc. It's an "Optonica 4705" (rare high end automatic table made by Sharp) w 1/4" tempered glass lid. Awesomely different, and fits perfect to a "T" on top of the Telefunken receiver with a lot of clearance under it as well. It nice to see a J arm again too. Linear, straight and J. I only want to keep two.

    The thing is... all three are awesome! OK, my point. They all sound great. The H/K is crystal clear (might be the cart but I cannot see any numbers and I WILL NOT unbolt it). It's elegant. The linear is very cool tech wise and sounds great too. Very clean but maybe not as "rich" as the H/K. Simple to use. The "Optonica" is kinda space age - that glass lid and perfect sizing for the Telefunken makes it really cool along w/ the chrome J arm. Even thought the platter sits very low inside the deck, it must weight 3 pounds! Very warm sound to this table. Reminds me of the 70's while listening to an album. I like them all. Why did I post this again?
     
    Last edited: Sep 12, 2017
  19. ferninando

    ferninando AK Subscriber Subscriber

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    just note that most if not all modern TTs have straight arms.
     
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  20. Eric Lloyd

    Eric Lloyd AK Subscriber Subscriber

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    Also consider how critical your listening might be.

    For example, I have a friend who is very particular about his sound and has the ears to know the difference. He prefers a very high end straight arm with a MC cart hung on it. I, on the other hand, have damaged hearing and a taste for rolled off high frequencies; I just can't hear everything well enough for true critical listening. Therefore, I prefer an S shaped arm because it's pretty and headshells are relatively inexpensive.

    More information is always better in this game but, when it comes to what you're going to play every day, make sure you really dig it.
     
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