More fun with microscope and AK’s new faster image loading

Discussion in 'Turntables' started by needlestein, Apr 10, 2018.

  1. c_dk

    c_dk Addicted Member

    Messages:
    6,152
    Location:
    West Michigan
    If you do the trig you can determine the width of the worn surface.......for this start at learning to measure wear we are assuming the wear is even in both RH quadrants......2X22 degrees or 44 degrees of the 60 degrees that are defined by a ellipse for the minor quadrants.

    We were taught that 22 degrees was approaching the limit of use as the wear is just exceeding the 300 millionths, 25 degrees you would be damaging the record.

    As you gain experience, just like the master mechanic who can read the wear on your tires, you can start differentiating the wear by each quadrant to determine if the alignment and other issues are affecting the stylus while in use.

    It takes practice that is tough to get today unlike like back in the 70s and 80s when I could examine 4-5 styli a day.
     

     

    Please register to disable this ad.

  2. needlestein

    needlestein AK Subscriber Subscriber

    Messages:
    7,529
    Location:
    West Hartford, CT
    Such was the market about ten years ago that you could get two of these and a cartridge for all of $80. This one is still unused.

    C18FBAB1-EF25-40DF-B1C9-A30B166278E8.jpeg
     
  3. onwardjames

    onwardjames Hoardimus Maximus Subscriber

    Messages:
    15,692
    Location:
    Kentucky
    This is a great thread. Thank you, Needlestein for all the incredible photos, and to c_dk for sharing your knowledge.
     
  4. needlestein

    needlestein AK Subscriber Subscriber

    Messages:
    7,529
    Location:
    West Hartford, CT
    While we are on this, I think I made a mistake with the Acutex. It seems to me that I only noticed the rear cut with that one, but this Ed Saunders has it, too, but it’s just not visible with the lens focused on the ridges—and maybe (most likely) all the others are the same. I’ll go back and check some. The narrow depth of field can make you miss things.
     
  5. c_dk

    c_dk Addicted Member

    Messages:
    6,152
    Location:
    West Michigan
    A professional lab grade microscope that can properly allow a reasonably accurate measurement of actual stylus wear will most likely cost north of $2000.00US.

    This is really outside the realm of the home user I would suspect.

    The other running thread about using a o'scope to calibrate a turntable is however very possible for the home user, especially with the availability of computer based scope programs.

    I would suggest that stylus checking should be put on the shoulders of local audio dealers and record stores. It is a tremendous opportunity to offer a service to local clients that can not be done online.

    The knowledge is out there, there are more of us still kick'en around who were taught how to do this.

    Time for local dealers to step up.
     
  6. needlestein

    needlestein AK Subscriber Subscriber

    Messages:
    7,529
    Location:
    West Hartford, CT
    Well, I’m trying to get beyond home user status and no one’s teaching this stuff. $2k is not a lot of money in terms of business investment. I’m already halfway there with my used SEK-2 and PEK-2. And weren’t those marketed to dealers, by the way? Or weren’t they? And there really isn’t a record store or audio store around here. I went to the one guy nearby and the experience was miserable and he never even ended up looking at my cartridge.
     

     

    Please register to disable this ad.

  7. needlestein

    needlestein AK Subscriber Subscriber

    Messages:
    7,529
    Location:
    West Hartford, CT
  8. restorer-john

    restorer-john Addicted Member

    Messages:
    6,063
    Location:
    Australia
    Look, it's great fun looking at stones under a microscope- we've all done it for decades, but where are the measurements?

    Let's see some useful frequency response plots of new vs worn. Let's see some testing of 40 year old styli vs brand new replacements showing distortion, channel separation/crosstalk etc. Let's do some low frequency tracking tests and show the differences between a visually 'worn' profile and a brand new one in the same cartridge body on the same arm and TT.

    Otherwise, it's just pretty images and commentary- nothing more.
     
  9. Pio1980

    Pio1980 AK Member Subscriber

    Messages:
    25,597
    Location:
    Angel Station, Alabama
    Or, we can go with an analysis of groove tracing vs tip profile vs contact patch shape and area vs wear.
    Physics.
     
  10. restorer-john

    restorer-john Addicted Member

    Messages:
    6,063
    Location:
    Australia
    None of that means a thing until the cartridge as a whole hits the test records and we measure the performance of the cartridge. Something sadly missing here.

    Same as looking at this engine in isolation:

    crate.JPG

    And somehow coming to a determination on how well the car it is placed in, will go around corners. It's a small part of a system and doesn't do anything in isolation. Yep, Physics.
     
  11. Pio1980

    Pio1980 AK Member Subscriber

    Messages:
    25,597
    Location:
    Angel Station, Alabama
    Yet, it does begin at the contact patch. Perhaps then, the parameters of a useful tool as test recordings, the Shure series, and the MicroAcoustics examples, plus some CD-4 recordings thru properly mounted and set up appropriate pick-ups, looking for attenuated and clipped hf tracing.
     

     

    Please register to disable this ad.

  12. Pio1980

    Pio1980 AK Member Subscriber

    Messages:
    25,597
    Location:
    Angel Station, Alabama
    Last edited: Apr 17, 2018
  13. Pio1980

    Pio1980 AK Member Subscriber

    Messages:
    25,597
    Location:
    Angel Station, Alabama
    So, the microscope can provide visual confirmation of what one may hear as a deterioration in SQ and listening pleasure not attributable to another cause/causes. How much wear is acceptable is how much tracing distortion is tolerable to the critical listener.
     
  14. needlestein

    needlestein AK Subscriber Subscriber

    Messages:
    7,529
    Location:
    West Hartford, CT
    I use test records all the time. I’d like to use, eventually, a laptop with a program that can plot response charts like I’ve seen others here do. But until I can get that set up, ya’ll are just going to have to wait or put it up yourselves. For me, this is my learning process and many of you are ahead of me. But there are plenty of others here who aren’t who, judging by the commentary, are enjoying the pictures and commentary. I’ve learned a lot from the pictures and commentary. But if I’m moving too slow, how about some suggestions with specifics. What computer programs are people using?

    Probably should go in another thread, too. I can see the value of that. With the right program, a scope is probably unnecessary if one can track sonic degradation. But a scope might still tell someone why their stylus is wearing out if since wear patterns also tell a story.
     
    L-82 and Nashou66 like this.
  15. c_dk

    c_dk Addicted Member

    Messages:
    6,152
    Location:
    West Michigan
    Where to begin......

    Since you can damage your test records with a worn out stylus any turntable checkup and calibration has to always start with a proper physical examination of the stylus with the correct microscope and procedure.

    Once you damage your test records your listening tests will be suspect.

    As to getting beyond the home user status I would dare to surmise that most contributors to these forums would rather invest 2k in 100 new records or a cartridge or preamp upgrade........

    The Shure test products were available to dealers via a plan similar to advertising copay. A certain percentage of your purchases went towards them.

    The Wild scope was a straight purchase from the importer.

    A successful business experience or relationship is always a two way street, it is not uncommon to read in various AK forums about lousy ones......
     
  16. Nashou66

    Nashou66 AK Subscriber Subscriber

    Messages:
    1,548
    Location:
    West Seneca NY
    @c_dk how many plays of the test tracks would it take with a worn or improperly set up stylus to
    ruin the record or specific test track?
     

     

    Please register to disable this ad.

  17. marcmorin

    marcmorin AK Subscriber Subscriber

    Messages:
    9,089
    beatcomber likes this.
  18. needlestein

    needlestein AK Subscriber Subscriber

    Messages:
    7,529
    Location:
    West Hartford, CT
    That's where I'm ahead of the game. I only need one record.

    [​IMG]
     
  19. c_dk

    c_dk Addicted Member

    Messages:
    6,152
    Location:
    West Michigan
    A severely worn stylus......just once.

    A improperly setup table....depends on what was improperly set and how badly.

    For example, too light of tracking force, allowing the diamond to rattle in the groove, will do far more damage than a number of plays with exessive tracking force.

    That's why the low tracking force marketing wars of the 70s led to the damage of so many records.
     
    restorer-john and Pio1980 like this.
  20. needlestein

    needlestein AK Subscriber Subscriber

    Messages:
    7,529
    Location:
    West Hartford, CT
    I wouldn't pull my ruler out and start measuring these photos. These are taken with an iPhone that focuses automatically and I haven't figured out how to do it manually, or indeed, if it can even be done. So, the camera chooses the focus and what to focus on. I often have to take a picture four or five times because the camera will focus on different things as the microscope image (and the fungus) confuses it quite a bit. This results in no two photos having the same focus or even the same focal point. Indeed, the Black stylus tip is a little blurry, so the contact patches probably look gigantic compared to the Gold. Personally, I couldn't tell much at all different between these two styli. The Gold is supposed to have more pieces, though, but maybe I don't know where to look to be able to tell. The Black cantilever also only has paint on one side of the length of the cantilever while the Gold is entirely painted. Maybe because of the black paint, these were the most difficult styli I've had yet to photograph. The image was so dark that there was no hint of detail. I finally got the bright idea to wrap the microscope in aluminum foil to reflect more light and that totally worked to get more light on the subject.

    3F2CEE1C-50A6-4F9B-BDE3-466BAC77312C.jpeg
     
    Last edited: Apr 17, 2018

Share This Page