Cartridge Alignment to Protractor Extremes

Discussion in 'Audio Hardware' started by avanti1960, Apr 3, 2021.

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  1. avanti1960

    avanti1960 Forum Resident Thread Starter

    Location:
    Chicago metro, USA
    Playing with turntables and LPs for decades yet we (I for sure) can always learn something new to help improve the sound.

    Recently with my Technics turntable using the supplied alignment jig proved a crapshoot at best, sometimes good, sometimes not. I find it not accurate enough for the best sounding alignment consistently, especially with more demanding cartridges and stylus shapes.

    The Mint LP protractor helped quite a bit but when actually reading the instructions the recommendation was to align the stylus to the tonearm arc at the extremes- by the spindle and at the edge of the platter, and not just at the null points.
    For years I have aligned the stylus to the arc just to the null points.
    A week or so ago I started to align the stylus to the extremes- the alignment that was "good" to the null points was way off at the extremes !
    I aligned the stylus to the arc at the spindle and edge of the platter and yes (of course :) ) the sound was better! But seriously, it did sound better- just a touch more solid in the center image and the confidence knowing that the alignment was as good as I could make it.

    Hopefully this helps- use a good protractor no matter what turntable you have and align it to the extremes. It is definitely more accurate.



    [​IMG]
     
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  2. vinylontubes

    vinylontubes Forum Resident

    Location:
    Katy, TX
    Yeah that's actually how the original Wally Tractor is used. There are actually those two spots that are checked before you move the stylus to the null points.
     
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  3. bever70

    bever70 Let No-one Live Rent Free in Your Head!

    Location:
    Belgium
    I never understood why people would just use the alignment jig that comes with their table (be it Technics or Thorens). It might be ok to get you in the ballpark but it can NEVER be as precise as using a protractor.
     
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  4. I purchased a Smartractor a few years back, one of the best audio investments I’ve made. It seems the cost has gone up though since I bought mine.
     
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  5. Brucedgoose

    Brucedgoose Forum Resident

    Location:
    Hawaii
    The Mint LP system is by far the best I have used, and I own the Dennesen Soundtrakor (aluminum version) as well (formerly my go-to). Any system that isn’t made specifically for your particular tonearm/cartridge combination is a compromise and cannot be totally accurate for all installations. Even the Mint LP system cannot take into account individual piece variations due to manufacturing tolerance variations, which at the level of the cartridge/cantilever can be significant. There is really no practical way to take these small but potentially significant variations into account, so even the very best, custom protractors, like the Mint LP, won’t be completely accurate for all cases, but I think its the best you can do.

    Have to reluctantly admit that as I’ve gotten older (66 now) it has become harder and harder to have the patience, good eyesight, and steady hand necessary to achieve “perfect” cartridge alignment. I use the Mint LP system, but rarely have the patience to get even that system absolutely perfectly dialed in. So I just get as close as I can using the best system I can find, and my failing eyes, and then try to forget about it,

    It would be very helpful if manufacturers of better cartridges would provide a spec for mechanical alignment accuracy of the stylus/cantilever, something with a tolerance like +/- 0.5 degrees from mechanically correct alignment. This would allow purchasers to know if it is even theoretically possible to achieve perfect alignment and it would be a good justification for some of the outrageous prices now being asked for good cartridges. Never gonna happen, tho...
     
  6. Ingenieur

    Ingenieur Just a dog looking for a home...

    Location:
    Back in PA
    Are the null points the beginning and end of a typical lp?
    I have a Cart-Align (40 years old lol) and it has 2 points that you try to optimize.
    Are these the null points?

    edit:
    One is 4.75 " from spindle
    The other 2.65"

    it looks the extremes are
    A bit less than 6" and over 2" ?
     
    Last edited: Apr 3, 2021
  7. Mister Charlie

    Mister Charlie "Music Is The Doctor Of My Soul " - Doobie Bros.

    Location:
    Aromas, CA USA
    Slightly OT but a question: If the VTA, VTF and overhang (using Technics gauge) are all correct, does it matter if the protractor (3 different ones) does not match up at all? Records play fine mostly, some have sibilance towards the end of the record. Some don't.
    Setting the cart to the protractor skews the cart in the headshell pretty substantially.
     
  8. missan

    missan Forum Resident

    Location:
    Stockholm
    There is no perfect alignment, only different ones that focuses on placing the lowest distortion on different parts of the record side. And very slightly so.
     
    Last edited: Apr 3, 2021
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  9. Brucedgoose

    Brucedgoose Forum Resident

    Location:
    Hawaii
    The null points are not the beginning and end of a typical LP. The null points fall within the grooved area of typical LPs. And the null points vary, depending in which alignment method you use (there are several, each with different distortion characteristics).
    I also have the Cart-Align system and it works well. Those *are* the correct null points for one of the possible alignments (not at the beginning and end-of-side) and that system works well, but, like all of these generic alignment protractors, it can’t be totally accurate unless it is designed for your specific tonearm/cartridge combination.
    This is not bad new, it is good news. It means you can relax about getting things *perfect,* since perfection isn’t really possible!
     
  10. Davey

    Davey NP: Hania Rani/Dobrawa Czocher ~ Inner Symphonies

    Location:
    SF Bay Area, USA
    Technics uses the Stevenson alignment with very slightly different inner and outer groove radius compared to the DIN or IEC standards. Stevenson sets the inner null point closer to the label for least distortion with records cut close to the label. Most protractors these days are for Baerwald alignment, so you would expect a longer overhang and about 1 degree more offset. Baerwald is optimized for lower distortion across the middle section of the record, so is better if you don't have a lot of records cut close to the label. Either one works fine, but you have to accurately set your alignment to the one you choose for best results. Any of the popular three alignments should result in low distortion play with a decent cartridge.
     
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  11. rebellovw

    rebellovw Forum Resident

    Location:
    hell
    I use the Dr Fiekert (spelling) protractor for both my Technics and my VPI. That plus a USB microscope to dial in the alignment. I'm happy with the results - slightly different than the plastic tool.

    [​IMG]

    I found the plastic tool off with the DL103

    [​IMG]
     
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  12. Brucedgoose

    Brucedgoose Forum Resident

    Location:
    Hawaii
    Yes, it does matter. Sorry!
    The sibilance is mistracking, and that is most likely due to incorrect VTF. You will need to experiment with slightly differing VTF settings (or a good test record), to minimize or eliminate the sibilance. Getting the alignment right won’t effect the sibilance much, but it will reveal more musical details in complex passages because the stylus will be properly seated in the groove. VTF effects this *dynamically,* but getting the alignment right ensures correct orientation of the stylus in the groove when at rest (and all other times as well).
    VTA is less critical, in my opinion. Just get the tonearm level and you’ll be close on this.
    This process is the biggest pain in audiophilia. Keep trying.
    One more thing I almost forget: Anti-skating. You need to get the anti-skating correct in order to completely eliminate the sibilance. Experiment, again, once you get the VTF right.
     
    Last edited: Apr 3, 2021
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  13. Brucedgoose

    Brucedgoose Forum Resident

    Location:
    Hawaii
    Yes, that’s correct. But whichever one you select, you’ll get the lowest distortion if you get your chosen alignment spot-on. Not easy to do in many cases.
     
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  14. Brucedgoose

    Brucedgoose Forum Resident

    Location:
    Hawaii
    Plastic is not dimensionally stable, so you’ll get different readings depending on the ambient temperature. This is why precision measuring tools are made of metal, not plastic and its why I sprung for the metal version of the Soundtraktor.
    The USB scope is a good idea. I gotta get one.
    Another plus for metal is that its recyclable, unlike plastic!
     
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  15. rebellovw

    rebellovw Forum Resident

    Location:
    hell
    Thanks - yeah - it does a pretty good job (the little plastic jig) great for a quick cart setup when you don't wan't to pull out all the bells and whistles (put on cartridge changing attire :) ). Nice to have options.
     
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  16. Leonthepro

    Leonthepro Skeptically Optimistic

    Location:
    Sweden
    Metal also grows and shrinks with temperature fluxuations.
     
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  17. rebellovw

    rebellovw Forum Resident

    Location:
    hell
    That would be some crazy fluctuations.
     
  18. Leonthepro

    Leonthepro Skeptically Optimistic

    Location:
    Sweden
    Under crazy temperatures sure.
     
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  19. Brucedgoose

    Brucedgoose Forum Resident

    Location:
    Hawaii
    Much, much less than plastic.
     
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  20. avanti1960

    avanti1960 Forum Resident Thread Starter

    Location:
    Chicago metro, USA
    "Null Points" are the two positions on the radius of an LP where the cantilever is perfectly tangent to the groove radius, made possible by the offset angle of the headshell to the theoretical tonearm length. It doesn't get any better than those two points when an LP is playing in those specific grooves.
    The goal in determining the null points and alignment is to have the least amount of distortion when playing a record from start to finish.
    There are slightly different alignment methodologies that favor the inner or outer grooves, it is an interesting topic- see Stevenson, Baerwald (Sp), Lofgren alignment, etc.
    The "Mint LP" protractor works perfectly for my Technics table, I have no complaints about distortion at any place on the record.
     
    Ingenieur likes this.
  21. avanti1960

    avanti1960 Forum Resident Thread Starter

    Location:
    Chicago metro, USA
    agreed. i believe that the technics gauge can be greatly improved for example.
     
  22. Indeed,as a mechanical engineer that is why inspection tables are made of granite,in my part of the world it can get cold or very cold and then it get warm and sometimes hot.
    When I was involved in the production of machine tools the machine bed,as its the datum,would be housed in a sealed tent to keep the temperature stable.
     
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  23. avanti1960

    avanti1960 Forum Resident Thread Starter

    Location:
    Chicago metro, USA
    yes like .0000008 in per degree !
     
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  24. Catcher10

    Catcher10 I like records, and Prog...duh

    I always use an arc protractor, the arc is designed so that it sets the overhang based on your tonearm length. And yes always set by the extremes and then check it all the way along the arc.............Especially after setting at the 2 null spots, you till should be exactly following the arc if all you did was some twisting.
    You have to then finish by checking azimuth since the twisting can put that out of alignment...............It's a delicate dance of all alignment steps.
     
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  25. Claude M

    Claude M Forum Resident

    Location:
    USA
    Going to order that "Mint LP" plastic thingy, thank you for mentioning it. This is starting to cost real money! A few bucks here, a few bucks there. Before you know it, it's a nice about!
     
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