Conrad Hoffman Phono Cartridge Protractor help

Discussion in 'Audio Hardware' started by stereoguy, Oct 14, 2021 at 9:58 AM.

  1. stereoguy

    stereoguy Its Gotta Be True Stereo! Thread Starter

    Location:
    NYC
    Hi Guys,

    Maybe someone could give me some advice..

    I'm having a heck of a time using the Conrad Hoffman phono cartridge protractor.

    Basically, its the overhang adjustment.....you have to position the cart so the stylus tracks the arc line all the way through the "swing". I am having FITS trying to get it to "Hug the Line" the whole way through.

    So...if I can get it so that it hugs the line from the beginning until it reaches over the record label and THEN it veers off course, is that good enough for an accurate overhang adjustment?

    TT: Rega P3
    Cart: Stanton 881
    Stylus : OEM Eliptical

    Many thanks for any help!!
     
  2. thegage

    thegage Forum Currency Nerd

    It only needs to follow the arc the stylus does in normal playback. Considering that the stylus doesn’t play the label, or the runout groove for that matter, you should be fine.

    But, you did check that the printout is accurate?

    JohnK
     
  3. Davey

    Davey NP: Broadcast ~ The Future Crayon

    Location:
    SF Bay Area, USA
    You should be able to set the overhang so that it exactly follows the arc all the way across the record, from outside to spindle. But for that to happen, the protractor needs to be generated for the exact mounting distance of the tonearm, and as above, it needs to be printed accurately and hole cleanly cut.

    Presumably you used 222mm for the pivot to spindle distance and you have enough room in the headshell slots to position the cartridge for the overhang of the chosen alignment? It's hard for us to know how accurately the tonearm is mounted, so could be the actual mounting distance is more or less than 222mm. Also, technically you can't follow part of the arc and not the rest, so it must be veering off course somewhere before the label, but sounds like you are getting pretty close, just tweak the overhang a bit more.
     
    Last edited: Oct 14, 2021 at 11:25 AM
  4. stereoguy

    stereoguy Its Gotta Be True Stereo! Thread Starter

    Location:
    NYC
    Hi guys, Thank you. Yes, I used a ruler and measured the markings for the 180 mm and 200 mm (they hit 18 and 20 exactly on my ruler, so I think it printed exactly. I left the default settings of the generator. Ok, I will try to re-adjust so it hugs the line of normal playback (I have an old Lp underneath it) . Last night I was very, very close, and when I went to tighten the screws down, I messed it up!

    thanks!
     
  5. patient_ot

    patient_ot Senior Member

    Location:
    USA
    The Stanton carts with the "wings" can drift easily when tightening down if you are not careful. Best thing you can do is once the cart is aligned but not tightened down, take a pencil and make marks on either side of the mounting bolts. If it shifts, loosen the bolts and realign to the pencil marks. Of course this assumes you aligned the cart right in the first place. Keep in mind also that the paper printed arc protractor can shift itself if you do not tape it down with painter's tape or the like. Lastly, Stantons need to be isolated from metal tonearm parts and headshells. Make sure you are using the little black plastic isolators the cart comes with or a set of nylon hardware with two sets of nuts to isolate the cart. Otherwise you can get a hum.
     
  6. Davey

    Davey NP: Broadcast ~ The Future Crayon

    Location:
    SF Bay Area, USA
    You mean the defaults for the groove radius and printer correction? You must've entered a value for the spindle to pivot distance. What type of alignment did you select?
     
    patient_ot likes this.
  7. patient_ot

    patient_ot Senior Member

    Location:
    USA
    Might be a good idea to post a picture of the protractor you made, OP. The CH program is very much "garbage in = garbage out" and it's easy to make mistakes...
     
  8. stereoguy

    stereoguy Its Gotta Be True Stereo! Thread Starter

    Location:
    NYC
    Here are the settings I used...I just left all the defaults in place:

    Spindle to pivot - 209
    Inner Groove 57.5
    Outer groove - 146-05
    printer correction X - 1 Y- 1
    Arm or TT Id - left blank
    Type- lofgrenA

    Was there a better number for the Spindle to pivot value? The cart was hugging the arc line fairly well even before adjustment .
     
  9. Ingenieur

    Ingenieur Going with the flow...

    Location:
    PA

    As @Davey noted, your issue is likely the 209 vs. 222 pivot-spindle distance.
     
  10. stereoguy

    stereoguy Its Gotta Be True Stereo! Thread Starter

    Location:
    NYC
    Do you guys recommend that I make the spindle value 222 and run the whole thing again?
     
  11. patient_ot

    patient_ot Senior Member

    Location:
    USA
    Arc protractors are specific to each turntable. You can't just use random or default numbers for everything and get a good result. The result will be way off.
     
  12. Ingenieur

    Ingenieur Going with the flow...

    Location:
    PA
    Yes, definitely
    That is a big difference and you have nice gear, get the best out of it.
     
  13. patient_ot

    patient_ot Senior Member

    Location:
    USA
    It appears that Rega spindle to pivot is almost always 222mm. I don't know offhand what type of alignment methodology Rega recommends. I personally use Stevenson, but many people prefer Lofgren or Baerwald. In any case, you will need to make a new protractor and toss the previous one.
     
  14. Boltman92124

    Boltman92124 Fish tacos.

    Location:
    San Diego
    I only make sure the stylus is hitting the arc at the two null points then align to the grids. Really focus on that and you're good to go. Also assuming you used the correct pivot to spindle distance(222mm) and printed it correctly. How did you keep your platter from moving with the Rega? Just curious. I like the Lofgren B alignment best (lowest overall distortion across the LP vs Lofgren A or Stevenson).
     
    Last edited: Oct 14, 2021 at 1:04 PM
    Ingenieur likes this.
  15. stereoguy

    stereoguy Its Gotta Be True Stereo! Thread Starter

    Location:
    NYC
    Thank you guys for the help! Really Appreciated. I will make the spindle 222, choose Lofgren "B" , reprint the protractor and try again! see, I've always used the Shure two point protractor, so this is new to me, but I think I'll be able to do this with some work.
     
  16. thegage

    thegage Forum Currency Nerd

    Good reply. I posted in haste without thinking further.

    JohnK
     
    Davey likes this.
  17. JackG

    JackG Forum Resident

    Location:
    NJ
    I put a small piece of packing tape over the spindle circle before cutting it out with an x-acto knife. Helps reinforce it a bit.
     
    rischa and Ingenieur like this.
  18. vinylontubes

    vinylontubes Forum Resident

    Location:
    Katy, TX
    Use 221.7 mm for Rega for Baerwald (Lofgren A)
    This is the Wally Tractor Spec. It should yield a 239 mm effective length with an overhang of 17.3.
     
  19. Boltman92124

    Boltman92124 Fish tacos.

    Location:
    San Diego
    Lofgren A or Stevenson will do better on the most inner grooves but Lofgren B better on the entire side of the LP. Just FYI. If you've had issues with inner groove distortion, you can try them all!
     
    John Moschella likes this.
  20. richbdd01

    richbdd01 Forum Resident

    Location:
    London
    This manufacturer sounds like Steve Hoffman/Conrad Johnson collaboration…
     
  21. Boltman92124

    Boltman92124 Fish tacos.

    Location:
    San Diego
    Right! Yeah, just tape it down but leave the protractor free for initial placement. Can't beat the Hoffman protractors for free! Lofgren B didn't require crazy placement in the headshell for me. Lofgren A needed a good nudge forward and more angle of the cart towards the spindle. Lofgren B just a little nudge inwards. Stevenson quite a bit further back in the headshell. I have all three printed out along with some others. Can be a trigger for OCD but that's what turntables are all about! I finally got a microline stylus which makes life a lot easier.
     
  22. Boltman92124

    Boltman92124 Fish tacos.

    Location:
    San Diego
    Vinyl Engine actually. Link has been up there for 10+ years. Don't know why anybody would ever pay for a protractor.
    My new alignment template generator- Vinyl Engine
     
    richbdd01 likes this.
  23. Davey

    Davey NP: Broadcast ~ The Future Crayon

    Location:
    SF Bay Area, USA
    Just a note, our friend here @Electric Warrior has a webpage protractor that is similar to the CH generator, so isn't OS dependent, and he's added some options not available on the CH generator. Very nice piece of software (and his username/avatar is one of my favorite albums too :)) ... Arc protractor generator - AlignmentProtractor.com
     
    Last edited: Oct 14, 2021 at 3:40 PM
    33na3rd, JackG and Ingenieur like this.
  24. Ingenieur

    Ingenieur Going with the flow...

    Location:
    PA
    very slick and easy to use for those of us computer illiterate :)
    Thanks
     
    Davey likes this.
  25. Ingenieur

    Ingenieur Going with the flow...

    Location:
    PA
    I bought my Cart-Align almost 40 years ago.
    No internet, or even really personal computers, for the peasants. Lol
    :D

    It does this one
    [​IMG]
     
    33na3rd and Boltman92124 like this.

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