• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Stylus Wear evaluation: "Cat's eye" method

BDWoody

Chief Cat Herder
Moderator
Forum Donor
Joined
Jan 9, 2019
Messages
6,948
Likes
22,625
Location
Mid-Atlantic, USA. (Maryland)
So I came across this thread the other day, which shows a method to evaluate the extent of wear on a stylus.

https://losslesssound.wordpress.com/2018/12/24/using-macro-photography-to-check-stylus-wear/

Seemed simple enough, so I set up my cheap little LCD scope and thought I'd check my cartridges, starting with the 310MC out of the SL-10.

Sure enough, there were two little eyes looking back at me. Looks like it might be a pretty good way to track wear... I'll have to do this every 50 hours or so and see if I can track a difference. Might be interesting also to record some sweeps and compare them over time.

Has anyone else used this method? Gotta figure out how big those eyes can get before it's a problem...


PICA0011.jpg
PICA0012.jpg
PICA0014.jpg
PICA0013.jpg
 

sergeauckland

Major Contributor
Forum Donor
Joined
Mar 16, 2016
Messages
3,440
Likes
9,100
Location
Suffolk UK
I've tried the same thing, but was also stumped by how they should look when new and when worn. Shure published some photos, but only of what the eyes look like on a spherical and elliptical stylus, not a line contact or any other profile.

What light source(s) did you use, as I found that made a huge difference to what the eyes looked like.

I ended up sending mine to Expert Stylus for evaluation, but might try again now that all my cartridges have been retipped recently.

S
 
OP
BDWoody

BDWoody

Chief Cat Herder
Moderator
Forum Donor
Joined
Jan 9, 2019
Messages
6,948
Likes
22,625
Location
Mid-Atlantic, USA. (Maryland)
What light source(s) did you use, as I found that made a huge difference to what the eyes looked like.

Mine has little lights on the side as well as around the lens.

That's the thing...I don't know what it's supposed to look like. I will start logging pics. I will likely be sending a couple off to be retipped, so tracking from new might be more useful.

My VM540 is still quite new, so I'll see what that looks like too. These things aren't cheap to Retip (the MC's especially, and my one P205CMK3) the more I can figure out what I'm looking for the better.



0108211843_HDR_copy_600x600.jpg
 

JP

Major Contributor
Joined
Jul 4, 2018
Messages
2,276
Likes
2,449
Location
Brookfield, CT
I find it very difficult to photograph, even through microscope, as the reflect light from the facets flare. After messing around for about 15 minutes, here's an NOS P205ED4, which has the same profile as your 310MC. You can see most of the polished area of the wear surfaces.

P205ED4.jpg
 

JP

Major Contributor
Joined
Jul 4, 2018
Messages
2,276
Likes
2,449
Location
Brookfield, CT
NOS 150MLX. Tried to get a shot where you can make out the fins.

150MLX.jpg
 

JeffS7444

Major Contributor
Forum Donor
Joined
Jul 21, 2019
Messages
2,347
Likes
3,508
I seemed to get pretty good results using a diffuse overhead light, and using a piece of junk mail to reflect light to the sides. My USB microscope has dimmable white LED lighting, but I've got it turned down low in order to avoid hot spots.
WIN_20210108_18_46_23_Pro.jpg
_DSC0294.jpg
 

JP

Major Contributor
Joined
Jul 4, 2018
Messages
2,276
Likes
2,449
Location
Brookfield, CT
Problem with these is that the focus and resolution isn't great enough to make a determination. I've seen facets looks an easy 4-5x+ larger than they really are when not in focus. They only thing I can determine from these pictures is that the 310 seems to have been run with poor AS, but even that only appears to present in one picture.
 

anmpr1

Major Contributor
Forum Donor
Joined
Oct 11, 2018
Messages
3,722
Likes
6,406
Do any McIntosh dealers still provide examination service? I think it used to be required in order to to get the franchise. At least our local dealer had one. I read somewhere that the stereoscopic microscope dealers used to use (sourced from Switzerland or Germany) is no longer made, the company having gone out of business. Possibly a long time Mac dealer might still have one.
 

sergeauckland

Major Contributor
Forum Donor
Joined
Mar 16, 2016
Messages
3,440
Likes
9,100
Location
Suffolk UK
I've just had an old Ortofon MC15 Super retipped with a 'Paratrace' line contact stylus by Expert Stylus. It's effectively brand new, I've just played two LPs to check that it works.

Here's what the cats' eyes look like on my USB microscope.

MC15 new stylus.jpg


Now that I've improved the lighting, one can clearly see the sharp edges of the line contact, with no wear patch yet developed. I'll try and get photos of my AT33 or TSD15, both of which have also been retipped with the Paratrace stylus, but now have had some use.

S.
 
Last edited:

sergeauckland

Major Contributor
Forum Donor
Joined
Mar 16, 2016
Messages
3,440
Likes
9,100
Location
Suffolk UK
Here's the AT33 with the same Paratrace stylus as above, but with now some 65 hours use.

AT33 New Stylus.jpg


It's hard to make a direct comparison as the lighting is different just due to the different positions of the cartridges, but I think this one shows the line contact, but with two very small wear patches brighter. My understanding from Shure's paper of some 50 years ago is that the bright patches get closer together as the stylus wears, but again, I can't say how close together they need to be before replacement, and whether that's the same for a spherical, elliptical or modern line-contact stylus.

S.
 
OP
BDWoody

BDWoody

Chief Cat Herder
Moderator
Forum Donor
Joined
Jan 9, 2019
Messages
6,948
Likes
22,625
Location
Mid-Atlantic, USA. (Maryland)
This is the main problem I've had with looking at styli with USB microscopes.

Got a couple of the P205CMK3 , and went back to the 310MC to see if I could do better with it connected through the computer.

That P205 looks more like what I figure a worn stylus looks like:


InkedSnap_002_LI.jpg


Moving the lights around clearly shows the polished areas.

The 310 looks pretty good...and it really sounds quite good. I haven't noticed any issues, but obviously don't know it's history.
custom1.jpg



I have a NOS AT312EP that I should take a look at.
 

JP

Major Contributor
Joined
Jul 4, 2018
Messages
2,276
Likes
2,449
Location
Brookfield, CT
The tip is completely out of focus on those. What you’ve circled on the 205CMK3 looks like the edges of the glue facet on the cantilever.
 
OP
BDWoody

BDWoody

Chief Cat Herder
Moderator
Forum Donor
Joined
Jan 9, 2019
Messages
6,948
Likes
22,625
Location
Mid-Atlantic, USA. (Maryland)
The tip is completely out of focus on those. What you’ve circled on the 205CMK3 looks like the edges of the glue facet on the cantilever.


Ok, that definitely helps...here's a better try.

InkedSnap_012_LI.jpg
 

Tom C

Major Contributor
Joined
Jun 16, 2019
Messages
1,501
Likes
1,370
Location
Wisconsin, USA
I got one of these:
That looks like serious business.
The two things I run into trouble with using a digital microscope are the difficulty in getting the object into focus, and the difficulty in positioning the scope when the objective is in situ. You can’t always get a good viewing angle and viewing distance when the cartridge is mounted to the tonearm. And VERY fine movements can send the object out of focus or out of the field of view. You have to solve those problems before you can develop an efficient work flow.
 
OP
BDWoody

BDWoody

Chief Cat Herder
Moderator
Forum Donor
Joined
Jan 9, 2019
Messages
6,948
Likes
22,625
Location
Mid-Atlantic, USA. (Maryland)
That looks like serious business.
The two things I run into trouble with using a digital microscope are the difficulty in getting the object into focus, and the difficulty in positioning the scope when the objective is in situ. You can’t always get a good viewing angle and viewing distance when the cartridge is mounted to the tonearm. And VERY fine movements can send the object out of focus or out of the field of view. You have to solve those problems before you can develop an efficient work flow.


I got one of the ones without the adjustable stand, and realized how much more useful that would make it.

Here's the setup:
0110211040_copy_918x918.jpg


Here's another picture of the 310... those other patches were all I had been looking at before apparently. Helps when you are focusing on the right thing...:facepalm:

Snap_014.jpg
 

JP

Major Contributor
Joined
Jul 4, 2018
Messages
2,276
Likes
2,449
Location
Brookfield, CT
Last edited:
Top Bottom