The Finish Line for your Phono Cartridge- Stylus Wear by Mike Bodell

Discussion in 'Audio Hardware' started by Bill Hart, May 24, 2019.

  1. Bill Hart

    Bill Hart Forum Resident Thread Starter

    Location:
    Austin
    It will be interesting to see what you find at 500 and 600 hundred hours. How long are you prepared to keep going after that?
    I'm happy to make a prediction, since I'm not the one doing the work-- the point of discernible microscopic wear with the one JICO stylus was 500 hours, but that is only the starting point. We still have the 'gap' between that first marker and when the stylus starts to mistrack or demonstrate audible distortion. Where that is on a timeline of play is what you are after, in addition to looking at what's happening to the stylus on a microscopic level, no?
     
  2. Ray Parkhurst

    Ray Parkhurst Forum Resident

    Location:
    Santa Clara, CA
    It's not clear at what point in physical wear the 3% limit JICO states will occur. I've never seen an analysis that I believed to be correct. Certainly some level of flat wear is acceptable or most of the anecdotes on long stylus lifetimes would not make any sense. Without a distortion meter, I can't say where the limit will happen. Does this mean that the study is meaningless? When I hit 600 hours or 1000 hours, and we can all see flats have formed, will some say that's OK, and others say it's time to replace the stylus? I can see a big argument coming, with no one having the data to support a conclusion. It might be good to discuss this now...

    My intent was to run the experiment until I saw the bottom contact span drop to 0.25 mil, which is where the flats will start hitting the edge of the groove bottom radius. It may be that the contacts have widened dramatically well before then, and it does not make sense to go that far. I suppose each stylus tip design, and even different ones within a production run, will have a different characteristic as they wear. Some will get too wide before they go too deep, and vice versa.

    I have no idea how long I will go, as it will depend on the results, and possibly on the discussion.
     
  3. Bill Hart

    Bill Hart Forum Resident Thread Starter

    Location:
    Austin
    Absent some sound clips of what the thing sounded like with a brand new stylus and at some point where you believe you are hearing distortion, I think we have to rely on you, Ray, for the audible part. Obviously, record wear will factor in here. I think you've got some people watching this-- and I'm glad you are doing it.
     
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  4. missan

    missan Forum Resident

    Location:
    Stockholm
    Yes I think it´s reasonable there will be some lapping. But the groove forces will vary with the groove angles, so the difference will be large; which means the lapping could be happening in some places, but not really at all at other places.
     
  5. Ripblade

    Ripblade Forum Resident

    Location:
    The Six
    It seems reasonable to me that groove dynamics will play a part in groove wear. So using a classical record that is usually less dynamic and often cut at lower amplitudes to increase playing time might yield a lower than average rate of wear. Typical rock/pop recordings are cut 12-18dB RMS louder than classical ones, which also means the stylus travels further in the course of a single playing.
     
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  6. Tullman

    Tullman I prefer analog

    Location:
    Boston MA
    Hey Ray, I have two questions, I may have missed. Are you cleaning the stylus after each play? I typically dab my stylus in blu-tack between plays. Do you know what to look for, as far as stylus wear?

    One thing you are proving is that records can endure many many plays. People with record collections need not worry about number of plays.
     
  7. Optimize

    Optimize Forum Resident

    Location:
    EU
    A great idea I think to look at the dynamics.

    When the same diamond stylus will travel and make contact on the grove walls exactly in the same place and height for each play. The only thing that will vary is that as the flat spots get bigger the diamond will distribute the wear on the grove walls on a bigger area. But essential on the same area all the time and presumably shift/go little further down when the diamond is worn on the booth sides and get "less wide" in the grove looking from the front profile.

    A method to look at the dynamic range to get a indication of it is record a track/the whole side. Into a computer and use the same analysis software as the "Dynamic Range DB" (Album list - Dynamic Range Database ):

    MAAT DROffline MkII

    But then we are not here to look at groove wear. It is the stylus wear that is the interesting part.
    So if analysing a record that is a "reference" that is played back again and analyzed again after X hours (500, 600..?) of wear on the stylus. Because if the flats on the diamond is wider then it can not track the higher frequencies and not reproduce them.

    Ahh I just realized that inability to produce different frequencies has nothing to do with dB that the software is looking for if not the highest frequencies is the loudest/quietest.. :cry:

    (I leave it here anyway, it may inspiring someone else.):)
     
  8. Ray Parkhurst

    Ray Parkhurst Forum Resident

    Location:
    Santa Clara, CA
    In normal playing I clean my stylus before each record side, but in this experiment I am only cleaning at each read point. The longest I've allowed the playing to go between cleanings has been 48 hours, or ~144 plays. I think that's going to be my standard for the remainder of the experiment, whether I image the stylus at that point or not.

    Regarding stylus wear, I believe I know what I look for, but perhaps you could describe what you look for?

    Before starting up again after the 192 hour read point, I gave the record a listen. It sounded great! I would not say it sounded better than at the beginning, but I did not notice any distortion or similar problems. Background noise was higher than at the beginning, but still less than many records I consider to be quiet. It still had a few ticks and pops, probably same ones it had at the beginning.

    I have a nearly new second copy of the same record, and a nearly new second copy of the same cartridge, so at any point I can make comparisons. I'm willing to make digital recordings to do the compos, but I need to invest in the hardware to do that. Maybe before the experiment is done I will have that capability in place, we'll see.

    Edited to add: has anyone used the super cheap MP3 encoders available on Amazon? There is a "DigitNow" which is like $14 and free shipping and comes with Audacity capture software. Will that give decent enough quality to hear differences in distortion we're talking about here?
     
    Last edited: Aug 5, 2019
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  9. harby

    harby Forum Resident

    Location:
    Portland, OR, USA
    Clickbait: "This guy played a record 600 times, you won't believe what it sounds like now!"

    You can record with a USB audio capture card into whatever computer you have nearby (Audacity is free open source software, so it also comes free with a Google search). You can save audio samples as MP3 for sharing, but some may like lossless FLAC instead. Save as WAV for your own use.

    To go real cheap, but good enough for making convenience CD-Audio-quality digital files of vinyl, with even a switchable phono pre, you can get Behringer U-Phono UFO202 for $29 shipped. You don't need to install any drivers just to record, but it has optional ASIO drivers for audio workstation software.
     
  10. Ray Parkhurst

    Ray Parkhurst Forum Resident

    Location:
    Santa Clara, CA
    I went ahead and purchased a USB capture card, so I should be able to share files at different points along the way.

    At this point I could have purchased the cartridge as "new" and would not even complain about its being used for 200 hours! The record still looks new to naked eye as well.
     
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  11. Tullman

    Tullman I prefer analog

    Location:
    Boston MA
    I do not know what to look for, nor do I have a microscope. In the past I noticed a degradation in sound from the cartridge when the stylus is worn. Usually distortion coming from on channel or the other.
     
  12. Ripblade

    Ripblade Forum Resident

    Location:
    The Six
    Leaves one to wonder how many thousands of hours were on the blunted needles you've imaged in the past...

    I'm also gaining more respect for the humble SL-10. It's how many years old, with how many rubber belts, and it still performs without flaw after nearly 200 hours straight? Pretty impressive...
     
  13. Ray Parkhurst

    Ray Parkhurst Forum Resident

    Location:
    Santa Clara, CA
    I've done a fair amount of listening to worn styli that I have viewed in microscopic detail, and I think I know what to look and listen for. That said, I'm sort of excited to get the digitizer so I can make audible comparisons and don't have to trust my memory or my ability to hear subtle distortions. For sure I am confident in saying when the stylus has reached its terminal state and is hitting groove bottom. That sound is very distinctive, and I've even been able to quantify it somewhat so I have an objective measure based on photomacrographic measurements. But I don't really trust my hearing/memory to say if a 0.25mil wide flat has more distortion than a 0.15mil. In fact, most of the worn styli I've listened to actually sounded very good, with no objectionable distortion I could attribute to the stylus, though some styli/cartridges have noticeable distortion even when new or barely worn.

    As an example, I have several Shure V15LT, and until recently they were my sonic reference for P-Mount cartridges. I have always been impressed with the consistency of quality of the VN45LT stylus, and indeed every one I own looks identical in shape. I have a couple new ones, as well as some with visible wear, and finally one with near-terminal wear. They honestly all sound about the same to me, and in fact the most worn one sounds slightly quieter and cleaner. It could be that due to its wear, it is pushing farther into the groove, which is affecting the sound, I am not sure. Bottom line is that it may be hard to separate the various effects.
     
  14. Ray Parkhurst

    Ray Parkhurst Forum Resident

    Location:
    Santa Clara, CA
    For sure those heavily-worn styli saw a lot of use. My expectation is that if I were to examine the TT they were on, I'd find the VTF was set very high, and anti-skating was way off, but who knows, maybe they were just used for many thousands of hours as you say.

    My "main" SL-10 has performed flawlessly for several decades. The record label light burned out years ago, and it has a lot more scratches and use marks, but the only thing that seems to happen to them is the linear rail gets sticky if it's not used. Running it in and out a few times cleans the rail and distributes lubricants, and it's good to go. I usually do this when I come back from a vacation just to make sure it is not sticky. To its credit, the one I'm using for the experiment was sitting unused for at least 5 years, and yet its rail moved full-scale on first run through. I have a 3rd one that is in need of some rail lube or something more drastic. It runs, but the arm won't advance. I need to get out the repair manual and give it some TLC.
     
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  15. Ray, you may have answered this somewhere earlier in the post, but what kind of microscope are you using and what is the magnification level?
     
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  16. Slick Willie

    Slick Willie Decisively Indecisive

    Location:
    sweet VA.

    I also have a SL 10...impressive unit IMO!
     
  17. Ray Parkhurst

    Ray Parkhurst Forum Resident

    Location:
    Santa Clara, CA
    Actually I don't think I have discussed it on this forum...

    I use a microscope objective mounted on a bellows with a Canon DSLR. The objective is a Nikon 20x.
     
  18. Ray Parkhurst

    Ray Parkhurst Forum Resident

    Location:
    Santa Clara, CA
    96 more hours completed, total 288 hours. The polishing of the contacts seems fairly complete, so IMO the stylus is now "broken in" from a contact perspective. It's encouraging that the contacts are being polished in the area predicted by the T-zero images. Until now the usefulness of the T-zero imaging in predicting contact formation was still a hypothesis, but now it's proven, at least on this stylus. This also means that the stylus is mounted in the tonearm at exactly 0-degrees of azimuth, such that the 45-deg imaging is in the same plane as the groove wall. It's nice when things line up as predicted!

    I did not image the tip this time, since I did not fine it useful and was too variable in earlier checkpoints. I may image the tip later once the flats start to form more visibly.

    What I see in the images below is that there are still no real flats formed. The Profile images at 288 hours vs T-zero still look the same to my eyes.

    I believe we can assume that the polished areas define the groove contact patches, and with good contrast in these latest images, the contact patch areas can be measured. They are:

    L: 0.27 x 0.45 mil
    R: 0.25 x 0.41 mil

    Here are the images:

    Left (inner) contact
    [​IMG]

    Right (outer) contact
    [​IMG]

    Front Profile view
    [​IMG]
     
  19. Ray Parkhurst

    Ray Parkhurst Forum Resident

    Location:
    Santa Clara, CA
    Here is an animation of the Left contact at 288 vs zero hours:

    [​IMG]
     
  20. Slick Willie

    Slick Willie Decisively Indecisive

    Location:
    sweet VA.

    Excellent work!!!
     
  21. missan

    missan Forum Resident

    Location:
    Stockholm
    I have been measuring some distortion at various freq. Without knowing exactly what JICO mean by 3% distortion, I believe this is a very low figure at high freq.
    If I measure 2nd harmonics with a tone of 8kHz I will get a higher figure, if I measure 2nd harmonics at 30kHz with a tone of 15kHz, the figure will be even higher.

    Maybe it would make some sense if measuring distortion when needle is new as ref. and compare with this at some intervalls.

    I don´t know; one could say it´s not perfectly clear how to do it.
     
  22. Ray Parkhurst

    Ray Parkhurst Forum Resident

    Location:
    Santa Clara, CA
    I might do this on a 2nd round of tests. I wanted to do a first round to work out the process and expectations.
     
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  23. Morbius

    Morbius Forum Resident

    Location:
    Brookline, MA
    Interestingly I recently read a review of an EMT Jubilee JSD 6 moving coil cartridge in the June 2019 issue of Hi-Fi News & Record review where in the electrical measurements for harmonic distortion were 13% lateral and 9% vertical at 10Khz with a brand new "Super Fine Line" stylus. This measurement to me seems typical of new styli based on a few other technical reviews of cartridges (recently Shelter and EAT) I've read in this magazine. Seems kind of erroneous that Jico should state 3% distortion at 15Khz for 400 hours use on a shibata/fine line when typical distortion for a similar new stylus at 10Khz is normally 3-5 times higher than that.
     
  24. Koptapad

    Koptapad Forum Resident

    14 year old AT 150MLX on a Technics SL 1200MK2. Unknown hours.
    I've had problems with this cart since purchase. The cant was angled off center so I had to loosen the set screw and straighten and other issues.
    Looked like poor QC and sloppiness to me. Then, at some point my kid had played with the antiskate and turned it up but I don't know how long it had been like that.

    Obviously looking for a replacement stylus and wading through options for the AT 150MLX cart.

    [​IMG]
    [​IMG]
     
    Last edited: Aug 11, 2019
  25. Thomas_A

    Thomas_A Forum Resident

    Location:
    Uppsala, Sweden
    Ray, perhaps this was noted before but it looks like the front has a flat cut not visible on the back which is smoother. I wonder if this is intentional or if it is just an manufacturing error. That sharp corner may or may not give rise to some vinyl shaving.
     

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