Microscopes are really useful!

[Wil de Vrede]

Oh, might as well post the record groove pictures too
Not that they're very revealing, but it's nice to fuzz with it
This is a Binas record (special recording technique) with very much room in between the grooves, they look like a 45 rpm Maxi single, but it's 33rpm:

[Wil de Vrede]

Have pushed the needle unit too tight on the cartridge, obviously  

Here I saw something was wrong:

[richard]

What did that needle used to be in its former life?
From where I'm sitting, the diamond looks good to me. But I can't see it very well.

[Wil de Vrede]

The needle seems to be allright...:



Yes, I was rather dissapointed to see that after checking for a start and putting the needle unit back tightly in it's place on the cartridge, a fixed v-shaped part of the cart cut off the oncoming cantilever. Which I think is a production fault. It should stay put at one moment, not untill the cantilever is touched by the cartridge!

So by checking the needle I ended up with a nice Philips GP401 cartridge with a, from sight, good original needle with a cut off cantilever.

[Lynnot]

Have you considered a cactus needle repair?

[richard]

Ah, Mortis,

I still don't know what this needle is, and I'd like to.
In order to evaluate the diamond's condition, I need to see an end-view, especially a shadow image.

All that we need to see are the two tiny points on the rounded end of the diamond where the diamond contacts the groove walls.

 Everything else in the image is irrelevant!

We need to be able to make out deviations from rounding as clearly as possible, which is why shadow images have been used so much in this work.
Other views are nice to look at, and with proper lighting, they can be useful for evaluation, too. The shadow image is easy to light. 3-d lighting is much more difficult to get right and takes yet more time and fussing. I'm not opposed to it!

Please understand that my Rule #1 is the same as that for medical doctors: "First, do no harm." This means that the record itself is what we want to protect, and that's the reason for all of this fussing with microscopes. Let's not overlook the reason for what we're doing.

I enjoy looking at various diamonds in color and at the cantilevers, and we can learn things here, too. But the two wear points are the hardest things to see, and I think that this is where we should concentrate our efforts. The other stuff is easieer.

[Lynnot]

My guess:

[JayM481]

Not "useful" shots, but some initial test shots now that I exchanged the 400x 'scope for a 300x one that is a bit easier to handle. The magnification is a bit shy of 300x.

DL103:


Jico SAS for Shure V15 III. Brand new - lots of glue.


Stanton 500


Richard, can you be specific on how to photograph them for wear analysis? I've seen elsewhere that the shot should be from the "record's perspective" ie shot from the cartridge body towards the tip. When you say "end on" is that what you mean, or end on from the tip towards the body?

[Wil de Vrede]

Hey Lynnot: That's the one!

Yes about the proper usefull pictures, allthough those above are nice to see, they're not of real use to see wear of contact surface. I know what Richard means, but they are so nice to see....

You have the same Jico as I have and you can clearly see how tiny the needle tip is compared to all other needles. And the Denon is a small one already...

[richard]

Hans said,

I know what Richard means, but they are so nice to see....

Ha ha ha.
I agree!

Jay asked,

Richard, can you be specific on how to photograph them for wear analysis? I've seen elsewhere that the shot should be from the "record's perspective" ie shot from the cartridge body towards the tip. When you say "end on" is that what you mean, or end on from the tip towards the body?

Your view can be head-on from the front, or from the rear. If it were a car, you'd be looking at the headlights. That's the front view. The best way to get the hang of this is to get your hands on a very grotty disgustingly worn-out needle. Find a way to hold it so that the microscope will see it head-on. Now, you'll see what a badly worn needle looks like. The wear will be unmistakable. Trust me: If the needle came from an ordinary record player, you won't want to use an arm without antiskating ever again. Light the needle from the side opposite the microscope's lens. If your needle looks like a chisel, you have struck gold! And there, you'll have a good example of what that needle has been doing to the records. We want to catch the diamond just at the beginning of wear visibility: that's when to replace it, to be safe.

Being able to see the flats just beginning to form may be even better, but harder to light and to see.
The needle can be at a slightly-incorrect angle ("VTA," not a sideways turn)  but you'll still be able to see what you want to see. So, just play around with this and you'll get the hang of how to do it.

Every cartridige maker's stylus has to be held differently, so I use little blocks and adhesive strips to get the diamonds into view.
Note that it's usually much more difficult to hold the needle for an end view than for a side view. This may be why so many photos are the wrong ones.

Special issues: of course, the quality of a microscope matters. The internal reflections can spoil things. A problem with digital microscopes is that if magnification is provided (or enhanced) digitallly, this process can, and will, produce "visual noise." So, it's good to have a microscope that provides a good, crisp, basic optical image. I want to see those two important wear points better than I can with the Intel/Mattel microscope, so I'm aiming to add another lens to it. The horrible software that comes with it can't be taken out of automatic mode, in which it "corrects" the image for lighting (brightness) and what it thinks is incorrect contrast. This is similar to digital cameras. In doing its corrections, the correction routine adds pixels, which is exactly what you don't want. Connecting the microscope to the computer directly via its inustry-standard interface makes things much better. It would have been considerate of Intel/Mattel, Blue Coral, etc. if they'd been generous enough to point this out in the instructions, but so many companies are too stingy to spend enough money on documentation for their customers.

Anyway, if you play around with the views and a couple of needles (especially bad ones), you'll really begin to get the hang of this. You'll look at a few needles from the end, and you'll say, "Wow: now I can see what Richard was talking about. This is really cool."

[GP49]

I have found that for me, the best way to observe the wear points on a stylus is to set the cartridge/stylus so that the stylus tip is
pointing TOWARD the microscope, with a light source arrayed so the light beam is horizontal.



If positioned correctly the light reflects off the rounded stylus tip exactly where wear occurs.  
A perfect stylus will have a perfect point of light reflecting off it.  Most new styli will show some fuzziness or surface texture.  
A stylus with some hours of use will show a visible "hot zone" which can be assessed as to "polish" vs. "flatness" by moving
the light source around or by rotating the cartridge/stylus around the axis of the stylus tip.

This can be trickier to do than to describe, at high magnifications.

[Wil de Vrede]

Yes indeed, trickier to do than to read
Right now I'm looking into buying a regular microscope, but what I hear is that for needles a magnification of a 1000X is far too much, even bacteria are visible according to a man selling those Olympus and Leitz scopes. And I should have a stereoscope to have a better view on surfaces. That looks obvious to me. He told me to test some scopes to find out... Guess that's necessary indeed.

[wer]

I have found that the biggest problem with microscopes is the depth of field, which afair does not improve even as they get more expensive. For that reason 1000x (or even 500x) will tell you very little about wear of a needle because you could not even focus on the complete compromised area. This is not helped by the fact that most of the diamond is transparent 
I have bought a microscope and found 150x - 300x magnification, and a light source oriented towards the wear spot (as described by Gene) will show an area of reflection roughly proportional to the amount of wear.
But you probably knew that anyhow ...

[ZZMoko]

Have you guys seen Michael Ferrers new site where he shows how to set VTA using a digital microscope here http://www.analogplanet.com/content/how-use-usb-digital-microscope-set-92-degree-stylus-rake-angle-sra

[stiften]

Very fine description, Gene.

This is the way I work too when examining my cartridges. Holding the cartridge in a small moveable vice or similar helps to keep the cartridge steady, making it possible to turn it ever so gently under the magnification and in relation to the light.

I use a LED lamp from Ikea as a supplement to the lamp that came with my stereo lupe. The latter has different filters to colour the light - sometimes useful the get a comfortable yet revealing light on the stylus.

And as Richards implies: Sometimes only one single "hot spot" is found - if the tonearm that ran the cartridge had no antiskating mechanism and/or drag in the bearings.