Macro Photos of Record Grooves

[ray_parkhurst]

It is when the groove width at the top hits the minimum RIAA spec.

 

[Thomas_A]

@ray_parkhurst , did you ever see the stylus tracking pattern along a groove? Like two tyre lines?

 

[ray_parkhurst]

@ray_parkhurst , did you ever see the stylus tracking pattern along a groove? Like two tyre lines?

Even brand new record grooves have such lines, so I am not convinced they are due to stylus wear. More likely they are artifacts of the manufacturing process, though I could be wrong. I'm still working on a database of sorts to understand what grooves really look like.

 

[egellings]

I called this "wear" since it only occurs on the leading edges of amplitude peaks. Not sure why a pressing flaw would only happen there, but I am not sure. This was the worst patch I found, and it does go to the bottom of the groove, but many other smaller ones are more localized. Here's a 2D view of another section showing several of these in a row, all on leading edges:

View attachment 287912

Agree. What gets me is how a mechanical medium like that can sound as good as it does with decent playback equipment.

 

[ray_parkhurst]

Agree. What gets me is how a mechanical medium like that can sound as good as it does with decent playback equipment.

Yes indeed, it is amazing.

 

[Thomas_A]

Even brand new record grooves have such lines, so I am not convinced they are due to stylus wear. More likely they are artifacts of the manufacturing process, though I could be wrong. I'm still working on a database of sorts to understand what grooves really look like.

Hm - strange that new record grooves would have it. Cutters should not make them. So what can it be?

 

[ray_parkhurst]

Hm - strange that new record grooves would have it. Cutters should not make them. So what can it be?

No, probably not the cutting stylus. Lots of other processes though.

 

[restorer-john]

I’ve seen your excellent pictures but it is difficiult to say IMO if these are completely flat with cutting sharp edges. Polishing in a modulated groove must include different angles and variying contact patch area as opposed to a stationary unmodulated groove. I can’t see it happening unless someone left it running in the runout groove.

I can now say for sure, having viewed maybe 50 or so random old styli from my scavenged cart/stylus boxes of various vintages and usage in the last week, that the wear does indeed present itself as very obvious flat areas with very sharp edges to the flat spots. It is trivial to see uneven wear caused by faulty/incorrect antiskate (more common than I would have expected).

I have been using my various optical scopes, with movable/fixed lateral slightly elevated diffuse lights. There is no need to go esoteric or lash out on a SEK-2, x150 to x200 on my trusty Olympus scope shows all the detail I will ever need.

I have some wonderfully worn, new and lightly used identical AT conical styli which demonstrate the textbook perfect Shure 'cat's eyes' in various stages right up to an almost flat screwdriver type heavily worn profile when viewed from directly above. Once seen, it cannot be unseen and it's much better to skip the cat's eye reflection and view directly with diffuse light, the flat wear surfaces themselves. What is also clear, is many of the salvaged styli and carts I pulled of stripped tables over the decades were in perfect condition. Others were heavily worn. Age had nothing to do with it. A V15 III original supertrack plus stylus from the mid 1970s appears unused with not even a tiny patch of wear.

As I don't really care for preserving my various test records, I think I'll try say 6 or 8 identical, but variably worn AT conicals ('cos I have a pile of them) for distortion, starting with the NOS styli and working back to the worst worn to see how bad THD becomes.

 

[pseudoid]

Phonograph Stylus Wear Experiment
From <https://www.audiosciencereview.com/forum/index.php?threads/phonograph-stylus-wear-experiment.44872/>

 

[Ron Texas]

It's amazing this system works as well as it does.

 

[Anton D]

Utterly fascinating thread.

Thank you for such efforts!

 

[antcollinet]

It's amazing this system works as well as it does.

It's why I can sometimes be seen listening with my lower jaw flapping somewhere in the region of my chest