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

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

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  1. BendBound

    BendBound Forum Resident

    Location:
    Bend, OR
    Simple answer is a worn stylus cannot be controlled by the sides of a vinyl groove. See this link to Arnold Schwartz' reprinted article in the NYT: The First Component Of Your Hi‐Fi System—Your Phono Stylus . And this Vinyl Engine link which has the images: Micro-Acoustics The First Component Of Your Hi-Fi System - - Stylus Replacement Guide - Vinyl Engine . In the second, is a link to the article that shows images. I tried to download the article just now, and I could not get my browser to get the pdf file.

    But what happens is as the cartridge wears flats, and the tip becomes flat head screw driver in shape, the tip is no longer contained by the record groove and begins to wear it along the stylus edge.

    I have a number of jazz lps at 45 rpm by Music Matters and Analog Productions, and I count them the same as a side of 33-1/3 rpm record. The travel on the 45 is fewer minutes per side, but in the average of things, the difference is minimum.
     
    Last edited: May 24, 2019
  2. Optimize

    Optimize Forum Resident

    Location:
    EU
    Another thing that are not addressed is that logically stylus should wear SLOWER the longer it is used.

    It should progressively develop wider and wider flat spot for each time unit it is grinded against the record groove.

    And we say that the greater the contract area is (the flat spots (one on each side)) the lesser the force is at each square area of the greater and bigger the flat spots gets!

    So the the widening of the flat spots is much faster and getting wider from 0 to 100h. But the widening of the flat spots should not be happening at the same pace let say the next 100h (from 100 to 200h).

    Just a thought when we only thinking of WHEN we should replace.

    That the the first 50h is widely different then the last 50h. There the there may not be any significant difference between the last 50h..

    It doesn't change anything it is time to change the stylus anyway.. but just a thought..

    [​IMG]

    When looking at the image below starts me to thinking of that the difference between the sizes of the spots on the left and right side.
    That is valuable information about how the user should adjust the VTF/antiscating for the next stylus. For the users specific records and the average grove modulation they have.
    Sorry now I am maybe overthinking it..

    [​IMG]
     
  3. BendBound

    BendBound Forum Resident

    Location:
    Bend, OR
    Actually, that was addressed in the article but perhaps in an oblique way. The rate of diamond wear remains the same, but the size of the flat grows at a much slower rate as surface area increases. Look at the Weiler chart. It's a semi-log plot. If that were a regular chart, the x-axis would be very, very long, if you know what I mean. So instead of a straight line, the wear function in flat size is a curve, like a logarithm function. In other words, it takes progressively longer time to incrementally enlarge the wear flat diameter, because now a larger surface area is wearing. But it only takes a little wear for the tip to be worn to a sufficient degree that the stylus tip is no longer fully contained by the record groove. That is one of the primary reasons why distortion begins when wear has reached a certain point.

    Shure's research makes the point (no pun intended) that the hours of use wear advanced tip shapes at about the same time. The JICO work effectively breaks down critical wear hours, or for me, the time when to have an expensive cartridge checked for critical wear. What makes this like "how long is a piece of string" is that every one of us has a unique system. We have different turntables, different tonearms, different cartridges, different VTF, different alignments, different level of care for our records, etc. So its easy to say, I'm different, my stylus tip will last 2,000 hours. I know for certain that folks who know what they are doing in retipping and tip manufacture will say they don't agree that stylus shape makes a difference in longevity of the tip and that frictional wear is no respecter of a diamond.

    Bottom line, don't take my word for it since I have not done the evaluations that Weiler did. At best, I've put together a white paper, a guide meant to help folks like us understand the issue of stylus wear, to help us understand the problem of critical stylus wear, or make a decision about stylus evaluation or even what kind to get next time. Have your tip checked if you can, listen for distortion, count play sides. But here is the deal, unless someone shows you definitive research, we are all in the dark. What would be great is for someone to take up the mantle and to record wear hours on a system, pull the cartridge off, photomacrograph it, reinstall it, and so on, then publish those results. I've moved to the show me stage. Just show me.

    The images were provided to me by Ray Parkhurst and they belong to him. He posts on the Vinyl Engine where he shows a lot more images. So we need to be aware when we repost his material, that he gave me only permission to use them. I asked him precisely the question you rhetorically ask above. He acquired that worn N99E and does not know the details of hours or set up, unfortunately. That gets back to the point I've made in the prior paragraph.
     
    Last edited: May 24, 2019
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  4. harby

    harby Forum Resident

    Location:
    Portland, OR, USA
    I wouldn't say "screwdriver" shape, because the groove that is wearing the stylus is not always perpendicular to the tip. It will still "round" the edges of the contact patch from the groove modulation, even as the contact becomes blunter. This wear doesn't make for a sharp wear "facet".

    [​IMG]

    What the wear does is instead make the contact patch even more oblong, so you have more tracing distortion.

    As you can see below, the conical tip fits in a modulated groove in a way that the traced waveform is "read" either too early or too late. This inaccurate tracing of the original groove is "distortion", a modified waveform.

    [​IMG]

    Of course, with higher frequencies, the width of the groove becomes altered by "pinch effect", high modulations have physically narrower groove cut by a sideways-moving lathe tip, and unless you also have a thin profile stylus, it will ride higher, more out-of-phase distortion of the original wave:
    [​IMG]

    Conical acts like an even larger than .7 mil stylus when worn. Other profiles depend on the taper of the diamond behind the contact point. As you can see in the previous image, the microline stylus would maintain its benefits even after extended wear.
     
  5. BendBound

    BendBound Forum Resident

    Location:
    Bend, OR
    Thank you for posting those images. When I linked in the Arnold Schwartz article I was trying to find images such as you showed. Well done.

    As for the profile of worn tips based on original stylus shape, my article has a link to a Shure SEK document. That document shows what I am talking about. I used words those folks and others used to describe wear shapes and processes. The one composite image (image four) I put together of wear for different stylus shapes came from Shure and they gave me permission to use it as I modified it. What I did was take the four basic shapes, resize them, put them together in Photoshop into the composite. It was easier I felt to see them that way.
     
  6. Boltman92124

    Boltman92124 Go Padres!!

    Location:
    San Diego
    My Denon 103 is 3 years old and I swap it out a lot with other carts. No clue on it's hours. Would imagine at least 750+. No tracking or distortion issues that I notice. Now I'm curious about a new one side by side with it though. It's also supposed to last 1,000 hours and up according to many.

    For the OP though, a couple of hours per day of listening is over 700 hours be the end of year one.
     
  7. The FRiNgE

    The FRiNgE Forum Resident

    It does become more polished, given the records are clean. Wear is more of an issue with a conical shape, since it makes more of a point contact on the groove wall. Without going into the science of it, the larger contact radius tends to wear a flat spot, which we do not encounter (not usually) with a 0.2 x 0.7 elliptical, nor a line contact. The conical was most popular on the typical mass produced record changer, which has no anti-skate. So.. the cantilever develops lean, and some twist, which throws off the azimuth in particular (with a conical tangent alignment isn't critical) In other words, the stylus eventually "leans over". This condition along with a flat spot, or chisel edge will tear up the groove immediately.

    A stylus with nominal wear, and a polished surface does not damage a record.

    For we audiophiles with decent turntables with anti-skate, record wear isn't a major concern. It can happen , but with far less frequency and severity.
     
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  8. BendBound

    BendBound Forum Resident

    Location:
    Bend, OR
    From your finger tips to God's ears. :cool:
     
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  9. Arliss Renwick

    Arliss Renwick Forum Resident

    Location:
    Vancouver, BC
    I have a Nagaoka MP-110 on the TT in my office. It gets about 4 -5 hrs of play, 5 days a week. I've had the cart since Aug. 2017, meaning it's way beyond the 200 hrs Nagaoka suggests. I bought a replacement stylus, and just examined it, and the currently running one with my USB microscope. They're nearly identical in appearance. And they sound exactly the same! I put the new stylus back in it's box, with a note ("check back in Sept 2019") stuck on it (now, I am very good at keeping my stylus-es and records clean, that might be helping prolonging it's life.)
     
  10. BendBound

    BendBound Forum Resident

    Location:
    Bend, OR
    If you don't mind telling me, what microscope are you using. I've been investigating them too, since all of this came up. Thank you.
     
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  11. Arliss Renwick

    Arliss Renwick Forum Resident

    Location:
    Vancouver, BC
    Pluggable USB 2 microsocpe.
     
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  12. BendBound

    BendBound Forum Resident

    Location:
    Bend, OR
    I was considering the Andonstar ADSM302 HD microscope.
     
  13. avanti1960

    avanti1960 Forum Resident

    Location:
    Chicago metro, USA
    thanks!
     
  14. Jelloalien

    Jelloalien Stylus Genie

    Location:
    Toronto, Ontario
    I think there is some translation issue going on there, they can last week beyond that with reas9nable cleaning and care
     
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  15. Arliss Renwick

    Arliss Renwick Forum Resident

    Location:
    Vancouver, BC
    Pluggable microscope is very basic, but is not so bad as far as viewing a stylus close up. Pretty outdated software, though - my Mac's not thrilled to be running it
     
  16. p.analogowy

    p.analogowy Forum Resident

    Location:
    Warsaw PL
    Great article! I have a Nagaoka and the first time I saw their 150-200 h estimate in the manual I wasn't sure what to think about it. However, I decided to follow their estimates and replaced the stylus every 300h or so. I am glad to see that this might have been a good decision. :agree:
     
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  17. Fdee

    Fdee Well-Known Member

    Location:
    California
  18. The FRiNgE

    The FRiNgE Forum Resident

    Your posting should win an award. You have clearly and concisely explained tracing distortion AND pinch effect. Both of these produce IGD, and for the most part relative to stylus shape and groove pitch. The greater the pitch, the greater the pinch effect and tracing error. Pinch effect causes the stylus to lift vertically in the groove. This vertical movement (out of phase) is not part of the signal cut into the record, therefore produced as distortion.
     
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  19. Bill Hart

    Bill Hart Forum Resident Thread Starter

    Location:
    Austin
    Harby, with exotic shapes, is it fair to say that the wear manifests by turning the stylus into more of an oblate spheroid across the groove so it is behaving more like a conical in its tracking performance (and the shape of the thing if looked at under a scope?).
    Thanks, good post.
     
  20. The FRiNgE

    The FRiNgE Forum Resident

    Yes and no, I think mostly no. The photo posted by @Optimize shows the wear pattern on a conical stylus. By the photo, the wear appears as a flat spot, which it mostly is, however should be slightly ovaled by the radian of stylus travel. The photo and others tend to defy the logic that the contact isn't at a fixed point... and it isn't. We have the angular pitch of the groove which bears around the stylus radius.. and not at a fixed point. The cantilever is vector that causes the stylus to move on a radian. In other words the stylus rotates slightly as it moves across a laterally cut groove.

    If we refer to the photos posted by @harby we can see the conical stylus induces tracing error. The lines drawn on the conical references its axial (or tangential) alignment in the groove. The drawing is not entirely accurate, as the tracing error in reality is worse than depicted in the drawing. The arc of the stylus changes its orientation as depicted by the parallel lines. These drawings do illustrate clearly how tracing error occurs, except the scenario is actually worse than depicted. (((( I digress ))))

    Records are not cut the same. Some cutting heads move laterally, others are pivoted (similar to a cantilevered stylus on playback) Some records are cut with less modulation, therefore less acceleration of the playback stylus. Less modulation translates into less tracing error, and less pinch effect, especially at the inner groove. The benefit of lower modulation is lowered distortion, and perhaps extended record life. The drawback of lower modulation is higher s/n by the inherent noise of the vinyl, and in some cases less dynamic range. (if the music program is of high dynamic content, then this necessitates highly modulated passages on the vinyl record) So does (reasonably) lowered modulation of the groove sound better? I would say mostly yes, if not excessively low, however louder always sounds "better" without compensation by your volume control.

    The music industry almost always produced what sells. The loudness war of the 90's was nothing new. It occurred in the 60's as the hot 45 RPM single was compressed, and cut as hot as possible so it would play louder on that portable record player. The hot cutting also reduces the audible effects of surface scratches, so a teenager could literally abuse the record, stack it on a record changer, and it would still play without producing ticks from scratches.

    The conical stylus BTW does track ok in a groove of lower pitch, a less modulated groove. The conical isn't bad on the outer bands of a 12 inch LP. It is TERRIBLE on a 7 inch 45, especially styrene. The problem is the tighter inner leadout groove, the tighter inner groove area, very tough to track properly. If anyone is concerned about chewing up a styrene 45 with a line contact (a legit concern) the huge numbers of used torn up styrene 45's were trashed by a conical stylus. I've had good luck with a quality (bi-radial) light tracking elliptical. (not a cheap elliptical that will also readily eat your styrenes)

    So, back to stylus wear. As I understand this, the conical is most vulnerable to developing a "flat spot" Does this cause a chisel edge? It shouldn't but it does.. Here's what I think, advanced wear could cause a sharp point at the stylus tip. This in conjunction to the typical lean of the stylus (on record changers without anti-skate) will score an ugly trench through the groove.

    The evidence isn't only in the photos. It's in the records. Just go to any thrift store, and count the numbers of torn up records. I estimate 99%+ that would be unsuitable for enjoyable listening on a good system. How did they get that way? Groove surfaces become etched by dirty play (and noisy) and secondly the scored groove by previous play on an unserviced record changer with a worn stylus.

    Saturday night rant, :rant: aren't you glad you're an audiophile? :goodie:
    Happy listening folks!!!
    Steve VK
     
    Last edited: May 25, 2019
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  21. BendBound

    BendBound Forum Resident

    Location:
    Bend, OR
    Steve, Thank you for that informative reply. What you note really demonstrates that we need to see the empirical data. Until we do, we are speculating, even if that speculation is top drawer.

    Line contact and micro ridge stylus are still made of diamond. That wears too, regardless of shape. Not at a slower rate either. But cecause they are designed to have a flat in essence from the get go, they sound better longer with less initial groove wear on super clean records. Perhaps that is your point vis-a-vis a spherical tip. But there is nothing magical about advanced tip shapes that make them somehow immune to the same frictional wear.

    The number of vinyl lovers I know who own a vacuum or ultrasonic record cleaning machine can be counted on one hand compared to many, many, dozens of others who frequent the local vinyl shops where I live. Folks play their precious records when they are dirty deep in the groove making the damage to them worse actually with a long-contact stylus tip. And that accelerates wear on these advanced tip shapes.

    Advanced stylus shapes sound better longer until they don't. And that transition can be fast. They also bottom out in the record groove just as spherical tips and are not contained by it. I worked to make the point about how in a stereo groove, the diamond moves back and forth, up and down, and in a groove that is constantly changing its width. The tip of advanced shapes in diamond styli get worked over. We see in Weiler's work, that for spherical tip shapes, wear enlarges the flats. That process of wear enlargement is quicker initially, then it slows, but proceeds at the same wear rate because of the properties of diamond against vinyl.

    That is why JICO found the number of hours to critical wear are progressive with more advance tip shapes. They last for 500 hours± instead of 200 hours.

    Again, I think we need to see the data. My main takeaway is that most of us don't really know what is going on and many of us, too many, overuse our stylus until it does real damage to our precious records.
     
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  22. Bill Hart

    Bill Hart Forum Resident Thread Starter

    Location:
    Austin
    Steve- all good stuff and I thank you for writing that out. The focus of my question to Harby is what shape does an exotic stylus shape assume as it wears? (Perhaps you did answer it and I missed it; i'm a little tired as I write).
    I don't disagree about used vinyl- believe me, I buy quite a bit, and have gotten to the point where even M- grading, and play grading doesn't necessarily inform me because of the differences not only in expectations but the performance level of the "record player." At the same time- and it's really an unknown, i have some records that evidence scuffs, abrasions (probably from being pulled in and out of a sleeve) suggesting some level of play back in the day that sound very clean. I use cleaning equipment, but that as you know won't fix groove chew.
    regards,
     
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  23. dconsmack

    dconsmack Senior Member

    Location:
    Las Vegas, NV USA
    All of my MicroLine type styli I’ve used over the last 10 years have been worn by 500 hours. Noticeably more distortion; confirmed by inspection under a microscope. 2.0-2.2g VTF, cleaned after every side, aligned with a Mint Best Tractor, antiskate set via Soundsmith instructions, and on vacuum-cleaned records in M- to new condition.
     
  24. Optimize

    Optimize Forum Resident

    Location:
    EU
    I learned a new word from @Bill Hart "groove chew". And that groove chew was something I tried to wash away in countless ways until I realised it had to be wear.. (groove chew) :)
    (When all other options are excluded then you must face the fact that the bonded fat MP-110 is. That is why shapes is interesting to minimise "groove chew"/wear.)

    I realize also that when looking at the flat spots in the image below that most likely the tone arm is level with the record surface (or lower at the pivot of the arm). In my opinion one of the more stupid set-up advice you can give but is stuck on the internet forever.

    Anyway you can see the two spots is close together on the same side of the cone (probably towards the pivot).

    Logically we want the modulation of the left and right channel that it pushes the diamond ideally along the drawn line to towards left and right side so the cantaliver can easier transfer the movement to the coils in the cartridge housing.

    But the flat spots punches the diamond forward when the contact point is behind the center as the line indicates. But when the diamond is glued to the cantilever it will not of course go forward and the resultant of the force will only puch it sideways.

    Anyway this is not ideal. And show that conical shape could benefit that "some" care of adjusting the SRA. Maybe it may not be sonically hearable. But I would not be surprised that if we could hear the difference between the setup the conical diamond in the picture had and a more correct one.

    [​IMG]
     
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  25. The FRiNgE

    The FRiNgE Forum Resident

    Groove chew! :evil: By what I see, I believe the two photos are at slightly different angles. The tip of the worn stylus is further north (referenced to the large outer circle from the photo perspectives) but does appear the wear pattern isn't exactly in line with the tip, really can't tell ... certainly uneven laterally. That's the nature of wear. When you have a bad setup, plus high skating forces, too many hours, dirty grooves, the arm pivot grossly too high or low, (record changers) a fatigued and sagging suspension, this is the result.
     
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