Why Would Azimuth Ever Need To Be Adjusted?

Discussion in 'Audio Hardware' started by jtw, Apr 18, 2017.

  1. jtw

    jtw Forum Resident Thread Starter

    Why Would Azimuth Ever Need To Be Adjusted? For turntables that come with an arm, isn't this set at the factory? Aren't most cartridges flat on the upper surface that gets mated to the headshell. If aftermarket arms are mounted to the plinth level, why would there even be a need for this adjustment?
  2. Spitfire

    Spitfire Senior Member

    Pacific Northwest
    Some cartridges have removable head shells so you have to adjust them.
  3. KT88

    KT88 Forum Resident

    You shouldn't, but as Spitfire states, some arms just have a pretty sloppy fit to their headshells and could use some fine tuning. It is also possible that a particular cartridge stylus isn't exactly perpendicular to the groove and so would benefit from fine adjustment in any set-up. That should be done at the factory as you suggest though. Nothing is perfect, ever. Not even on fully adjustable and finely adjusted arms. The record itself is often way more problematic than the arm / cart as it changes every time you change a record and you have no control over the quality of the Lp. It is what it is.
  4. thegage

    thegage Forum Currency Nerd

    All cartridges aren't perfectly square
    All arms aren't perfectly manufactured
    All cantilevers aren't perfectly aligned
    All styli aren't installed perpendicular

    That's just the reasons I can think of in 30 seconds.

    For some people it matters, for others they just put down an LP and Play.

    John K.
    tmsorosk, ddarch, bluesky and 8 others like this.
  5. advanced101

    advanced101 Well-Known Member

    I envy these people.
    bhazen, bluesky, chili555 and 3 others like this.
  6. chervokas

    chervokas Forum Resident

    The thing is, with turntables, you're talking about trying to trace microscopic groove wall squiggles so anything that's off at a microscopic level -- an tiny little vibration that causes the stylus or arm to move microscopically, and tiny microscopic misalignment -- will have some impact on how well and how accurately the stylus traces the groove. Between flaws in manufacturing, the need to build products to a price point (it's not NASA building a mission critical part for a moon mission), differences in conditions from place to place, and the fact that the arms are mounted and the carts are mounted by imperfect humans, everything can do with some fine tuning in situ (and occasional checks of that fine tuning). Like @KT88 says, records are different thicknesses, never perfectly centered, not always perfectly flat, so however you get your cart set up with your test rig doesn't mean it won't be off from record to record. We do the best we can. Really it's amazing that the crazy Rube Goldberg/Flintsones kind of contraption a record player is, works as well as it does.
    Gramps Tom, ddarch, BuddhaBob and 5 others like this.
  7. Guildx500

    Guildx500 Forum Resident

    In addition to the reasons stated above it is necessary if you have a unipivot tonearm.
    thesisinbold likes this.
  8. jtw

    jtw Forum Resident Thread Starter

    If this is true, I'd be really disappointed. How hard can it be to beat an eyeball and a mirror?
  9. jtw

    jtw Forum Resident Thread Starter

    I think you meant to say that some ARMS have removable head shells. The ones I've seen have slots machined into the head shell and arm.
    The FRiNgE likes this.
  10. toddrhodes

    toddrhodes Forum Resident

    South Bend, IN
    If you've ever set up azi with a Fozgo, it's completely clear why it's such a fickle setting. Seemingly imperceptible changes in angle make for obvious changes on the meter.
    ddarch and russk like this.
  11. jtw

    jtw Forum Resident Thread Starter

    I hear ya. But knowing this, it is in the best interest of the manufacturers to get it right at the factory, so that their products sound as good as possible right out of the box. Most people use a mirror, at most. Most people have tables that make azimuth adjustment relatively difficult.
    toddrhodes likes this.
  12. Catcher10

    Catcher10 I like records, and Prog...duh

    Do you know if the factory uses a Fozy meter or Oscope to set this up? Or do they just eyeball it? I suspect they eyeball it and just set the tonearm/headshell level with the platter. Any fine adjustments need to be done by the end user, because I assume at some point you will change cartridge and what the dealer/factory did is a mute point now.

    Azimuth may not matter as much with an elliptical stylus, but the second you slap on a line contact, shibata, microline type stylus you better give it some due and TLC, or you might as well burn some of that money you spent on that cartridge.
    This is the point where I question when people state their higher end stylus type cart does not sound any better, if you do not invest in the tools and time to set that cart up right it will NOT sound good and may damage your records as well as cut life off that spendy cartridge.

    I used mirrors before trying an oscope and now a Fozy meter. the adjustments are very fine but the outcome is hear-able.
  13. jtw

    jtw Forum Resident Thread Starter

    Maybe my geometry isn't very good. If a cartridge manufacturer does its job, and makes the cartridge, stylus, and cantilever square and true (which benefits them), switching from one cartridge to another shouldn't make the azimuth change. VTA, yes.
  14. slovell

    slovell Retired Mudshark

    Chesnee, SC, USA
    Ever had a unipivot arm?
    Mike from NYC likes this.
  15. toddrhodes

    toddrhodes Forum Resident

    South Bend, IN
    It's not your geometry that's questionable I don't think :) It's your expectations that every cart that walks out of a factory will be perfectly square and that the cantilever is perfectly perpendicular to the cart body, along with the stylus being affixed at the perfect angle - every time - that are flawed. I've heard one account from an ex-VPI dealer that they couldn't get the pivot-to-spindle within a mm of the same distance on any table that passed through his shop. So if something that macro can't be precision, scale that down to perfectly aligning something the size of a blood cell attached to a rod the thickness of a few human hairs and it's pretty clear - if you expect that, you'll be paying big bucks for the skill and QC (and throwaways) to meet those expectations. :)
    SandAndGlass likes this.
  16. KeninDC

    KeninDC Forum Resident

    Virginia, USA
  17. Spitfire

    Spitfire Senior Member

    Pacific Northwest
    You're right.
  18. Bronica S2A

    Bronica S2A Active Member

    I suppose it was done at the factory - 47 years ago.
  19. Catcher10

    Catcher10 I like records, and Prog...duh

    The reason to adjust azimuth is two fold 1) Eliminate/minimize crosstalk and 2) channel balance. This, to my knowledge, can only be achieved by reading the electrical output of your cartridge while playing a 1KHz tone from a test LP. How you read measure that is up to you, some folks just listen thru headphones and adjust till what they hear is even/centered in their head...OK.

    But if you want to maximize soundstage and minimize surface noise, IMO it needs to be more precise than this. Adjusting VTF and VTA can affect azimuth, I have seen it on my Fozy meter...
    Also the higher end carts are usually hand made, hand spun windings, I doubt one will ever be like the other.
    Mike from NYC and Grant like this.
  20. Grant

    Grant A Musical Free-Spirit

    Sound and performance can be affected by variances as small as a millimeter.
    ddarch likes this.
  21. Apesbrain

    Apesbrain Forum Resident

    East Coast, USA
    Or a Well Tempered.
    slovell likes this.
  22. jtw

    jtw Forum Resident Thread Starter

    What are the tolerances on racing engine builders?
  23. jtw

    jtw Forum Resident Thread Starter

    Are you saying that the optimum is not the absolute vertical position, or that the absolute vertical position is best established using the 1Khz tone?
  24. chervokas

    chervokas Forum Resident

    True, the way we do cartridge setups by eye leaves a fair amount to be desired. If someone really wants to adjust azimuth more accurately they's measure channel to channel crosstalk electrically using a test record. And since another of the imperfections in cartridges is going to be channel imbalance of the generator the best set up may be for equal levels of crosstalk between the channels which may not be physically perfect azimuth. Or you could not worry about it. I don't, I use a Rega arm. But there are ways of adjusting azimuth more accurate than by eye. Here's one suggested method: How Do I Set The Azimuth Adjustment On My Cartridge? | Soundsmith
    ddarch likes this.
  25. The FRiNgE

    The FRiNgE Forum Resident

    Good point, a millimeter is a relatively large unit of measure in any mechanical system. Engine builders measure in thousandths of an inch or mils. The clearances in engine building are very similar to alignment of a stylus. An engine must have the proper main and connecting rod clearances to maintain oil pressure and to prevent metal to metal contact (or bye bye engine) Likewise, a stylus misaligned tends to gouge itself into the groove wall. More importantly, a stylus does not have the assistance of oil and oil pressure to lower friction, and prevent direct contact. In fact a stylus makes intimate contact with the groove.

    All we have to prevent groove wear or damage, is a polished stylus surface, the oil based lubricity of PVC, and alignment of the stylus in the groove. I may add, also a clean groove, as particles increase friction and heat, and also etch and gouge the groove walls. Playing a record is a mechanical operation. The stylus and groove are bearing surfaces.

    In the interest of higher fidelity, for those who pursue excellence in sound, it is a fairly simple base line. The groove must be clean. The stylus must be aligned (and clean).
    ddarch likes this.

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