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Cartridge Alignment to Protractor Extremes

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

  1. AKA-Chuck G

    AKA-Chuck G Forum Resident

    Location:
    Washington NC
    Not IME. The younger crowd buying a lot of vinyl and cheap turntables really have no clue about setting up a TT. They are depending on it being preset up like the Rega RP1 and cheaper models with cheap carts already installed. That's the average person. :wave:

    This crowd, OTOH, like fiddling around somewhat. Always changing things. I'm included in that group. A group that probably includes less than 5% of TT buyers. But we buy expensive toys and even those can be preset up with the cart of your choice already installed.

    Some are doomed to CD's and MP3. :wave:
     
  2. Brucedgoose

    Brucedgoose Forum Resident

    Location:
    Hawaii
    Yes, exactly. You’re provin’ my point.
     
    JackG likes this.
  3. AKA-Chuck G

    AKA-Chuck G Forum Resident

    Location:
    Washington NC
    I looked at your profile. That's not average!:righton:

    Actually the fact you are here is proving my point.
     
  4. StratDoc

    StratDoc Active Member

    Location:
    Chattanooga, TN
    I am in the right place, because I definitely fall into the OCD category. Really love tinkering with this stuff and always looking for ways to improve the sound.

    So I realigned this morning using Conrad Hoffman template with Lofgren A since that seems to best match the pro-ject x1 tonearm of 218.5 effective length with 18 over hang per pro-ject website. I used 200.5 for pivot to spindle distance. The calculate specs from the template come darn close to the pro-ject specs.

    The cartridge is mounted almost at the end of the head shell - quite different from where it was more centered using the dbsystems protractor. Somehow doesn't seem right???
     
  5. avanti1960

    avanti1960 Forum Resident Thread Starter

    Location:
    Chicago metro, USA
    to change to a different style of alignment the cartridge has to move.
    moving the cartridge forward in the headshell will move point of tangency further inoard and presumably bias the alignment for lower distortion on the inner grooves.
    check it with the protractor to make sure that the stylus traces the arc and that the cantilever is parallel to the runway lines at the two null points. if everything lines up, give it a spin and take a listen...
     
  6. McLover

    McLover Senior Member

    Location:
    Athens, Tennessee
    How precise with a Technics do you need to get? Choose Stevenson with the gauge, or choose Baerwald or Loefgren A alignment geometry. I can align a Technics headshell, by eye, and get it close to if not dead on.

    I only use the Technics gauge to double check my work. I demand accuracy and the performance I paid for, and I get it too. And this is checked using a protractor as well, if I use Baerwald/Loefgren A geometry and VERIFIED with a professional grade test record like the CBS Laboratories series.

    For me, the results matter, low record wear, and not mistracking matter. Choose one alignment geometry, use the proper protractor, or gauge and enjoy the music.
     
  7. Davey

    Davey very clever with maracas

    Location:
    SF Bay Area, USA
    Do you have the DB Systems protractor shown below? The null points are marked at 2.60" (66 mm) and 4.76" (121 mm), which corresponds to Lofgren A/IEC alignment. If so, the resulting overhang should've been 19 mm when adjusted for tangency at both null points, versus 18 mm for the Lofgren A/DIN alignment you are currently using with the CH protractor (I think), so agree, something isn't right. Maybe you just didn't have overhang set right with the DB protractor? The Lofgren A alignment results in the most overhang of the three, so the cartridge often does wind up all the way forward, and sometimes it can't be reached, depends on the cartridge design and where the stylus falls in relation to the mounting holes, which unfortunately is not standardized.



    [​IMG]
     
    33na3rd and Brucedgoose like this.
  8. MattHooper

    MattHooper Forum Resident

    Location:
    Canada
    I may have thought the same at one point, but I've found vinyl so rewarding it's become by far my main music source. Hence I want to optimize that source, just as I'd want to optimize my speakers in my room. A lot of people (non-audiophiles) just buy speakers and plop them anywhere not thinking of optimizing the sound, where we audiophiles care about the sound so we'll spend the time to dial them in to just the right position. Same with turntables. I grew up with turntables and frankly don't remember ever fussing with them at all. I don't even remember changing a cartridge! But now I really care about sound so...I'm fine with fussing a bit. My previous cartridge lasted 3 years. I'm find with spending a couple hours if need be to set the replacement cartridge up to enjoy the same quality of sound for another three years, given records will be almost all I listen to, and I really appreciate the nuances of great sound.
     
    avanti1960 likes this.
  9. StratDoc

    StratDoc Active Member

    Location:
    Chattanooga, TN
    Yes, that is the DBsystems protractor that I used for initial alignment. I now have the cartridge aligned for Lofgren A/DIN as you mention. It did push the cartridge out the end of the head shell but traces the arc perfectly and is parallel aligned with the grid. Maybe I did have my first alignment off. I will be interested to hear the sonic difference this evening and will report back.

    A quick question, with the a DBsystem type protractor you are only aligning at the null points. If I generate a Conrad Hoffman Lofgren A/IEC template with a 200.5 spindle to pivot distance and align first with the DBsystem, would I expect the stylus to trace the arc?
     
  10. Davey

    Davey very clever with maracas

    Location:
    SF Bay Area, USA
    No, even though they are both using Lofgren A (Baerwald) geometry, the DB Systems uses IEC spacing of the null points while you are now using DIN spacing to match the Pro-Ject specs, and hence the resulting overhang is a different value (and offset too, but that won't affect the arc tracing). You would have to select the IEC inner groove radius and generate a new protractor to match the DB Systems null points. That would also push the overhang even closer to the headshell limit since it would add about 1 mm.

    I think the main lesson to be learned is that it is much harder to get the overhang set correctly when using a 2-point universal type protractor, as you've apparently experienced. You can get very close to correct alignment at both null points even with overhang set incorrectly, but to get spot on, it is much easier with the arc protractor.
     
    Last edited: Apr 7, 2021
    patient_ot likes this.
  11. Randoms

    Randoms Aerie Faerie Nonsense

    Location:
    UK
    This is the Linn speed chekker which you can see has a dimension showing 229.0mm To centre of the arm collar.

    [​IMG]

    [​IMG]

    Many arms have a degree of movement in the arm collar mount, some more than others:
    certainly those that use the Linn mount (Linn, Jelco, Pro-Ject, Alphason, Syrinx - Audio Origami etc.) the arm collar first needs to be set in the correct position.

    Since the late eighties Linn have made the Kinky available. Having checked multiple dozen, there were very few set originally set to exactly 229.0mm. If you see the picture below, the Kinky should easy to easy to remove and drop back into the arm collar (with grub screw wound out) over the centre spindle.


    [​IMG]



    Edit. Without this critical dimension being correct, obviously you will not be optimising the cartridge alignment - any gauge that using the centre spindle for reference will give false readings.....
     
    Last edited: Apr 7, 2021
  12. StratDoc

    StratDoc Active Member

    Location:
    Chattanooga, TN
    Last edited: Apr 7, 2021
    Brucedgoose and Davey like this.
  13. avanti1960

    avanti1960 Forum Resident Thread Starter

    Location:
    Chicago metro, USA
    well said. i call it "working" the system to get the best sound out of every possible component. turntables and cartridges are the most mechanical and provide good return on effort IMHO.
    i have not reached the level of putting isolating pucks under everything, cable trestles or power conditioning. no offense to those that do....
     
  14. Brucedgoose

    Brucedgoose Forum Resident

    Location:
    Hawaii
    I had a hard time with the Db Systems protractor, too. Also came close, but not perfect, with the Mint. Living happily with maybe slightly imperfect, but nevertheless really good sound now.
     
  15. Davey

    Davey very clever with maracas

    Location:
    SF Bay Area, USA
    Yea, I misread your question above about the DB Systems protractor and basically just restated what you already said about making a protractor with the IEC radius, you obviously get it all now :)
     
  16. StratDoc

    StratDoc Active Member

    Location:
    Chattanooga, TN
    Since the cartridge is now more forward in the head shell, would stand to reason need to re-calibrate the tracking weight?
     
    Brucedgoose likes this.
  17. Brucedgoose

    Brucedgoose Forum Resident

    Location:
    Hawaii
    And, of course, if you change the weight you’ll have to change the anti-skating. :)
     
  18. Davey

    Davey very clever with maracas

    Location:
    SF Bay Area, USA
    Just a quick calculation, but moving the cartridge 1.0 mm forward on a 218.5 mm tonearm looks to be just under 1% change in tracking force, not very significant. But by all means check it, I may be off, and it would be fun to know what you see :)
     
  19. StratDoc

    StratDoc Active Member

    Location:
    Chattanooga, TN
    Weight was off slightly as you thought. I must say, the sound quality to me is worse after all this effort. Listened to some Allman Bros last night and the bass is not a solid, and mid range is washed out. Not hearing sibilance, if anything the highs are more pronounced. Followed that with a little Muddy Waters from the band recording Last waltz and the stylus picked up a lot of static and skipped for the first time on that album.
     
    Brucedgoose likes this.
  20. Claude M

    Claude M Forum Resident

    Location:
    Bergen County NJ
  21. formu_la

    formu_la A.I.

    Location:
    Toronto, Canada
    If you print one for free, what is the difference except it's not shiny? The correct scale can be easily verified as they provide marks for that.
     
    csgreene and doctor fuse like this.
  22. avanti1960

    avanti1960 Forum Resident Thread Starter

    Location:
    Chicago metro, USA
    how long did you use the cartridge with the previous alignment?
     
  23. StratDoc

    StratDoc Active Member

    Location:
    Chattanooga, TN
    Maybe six weeks ago, listening on average a 2-4 hours a week. Previous alignment with dbsystems was correct in terms of null points, but over hang was off relative to this alignment.
     
  24. Brucedgoose

    Brucedgoose Forum Resident

    Location:
    Hawaii
    Here’s a suggestion; next time you get things close enough that it sounds pretty good and is tracking pretty good - *mark* the position of the screws holding the cartridge in the headshell so you can return to the same position. You can do this with a mini- screwdriver - with the tip of the screwdriver, gently outline the head of the screws on the top of the headshell so you leave a slight scratch surrounding the spot on the headshell where the screws attach. Then, if the next position you try isn’t an improvement, you can easily return to the previous position. You should only do this when you're pretty close, and it assumes you‘re making the adjustments at the headshell, not the tonearm base.
    Also, a minor alignment error should not cause mistracking (skipping). It just increases distortion. Skipping is more often caused by incorrect tracking force and/or incorrect anti-skating. So sorry you're having such problems! I know what a PITA this is!
     
  25. Brucedgoose

    Brucedgoose Forum Resident

    Location:
    Hawaii
    A lot of people have mentioned making their own alignment protractors and/or printing them from templates on the web. Here’s why I don’t take this approach. When using a protractor printed with a laser printer on normal paper, the period used to designate null points is significantly bigger than the stylus tip itself, so where exactly in the period do you set the stylus down? The spreading of the ink as it dries on the paper creates a spot too big to be used to set a really accurate null point. The same is true, to a lesser extent I think, with laser-printed arc protractors because the thickness of the arc, when printed on normal paper, creates similar ambiguity about exactly where on the line the stylus should sit. For these reasons, as well as longevity, I prefer metal or even plastic over paper or cardboard. And the lines and spots need to be really thin!
     

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