USB Microscope

[jaspert]

Has anyone used a USB digital Microscope to inspect the styli  or help in setup? The buzz word for some obsessive vinylphiles   seems to be SRA?  Cheap enough from ebay to experiment i think.

[skippingjack]

I've not got one yet, but I believe one might be coming along for my birthday. Seems like a good idea to me and I know that they're good for electronics repairs etc.

Alex

[daiwok]

Been looking at one for a long time ....... but the resolution is not quite there yet. I will have another look again as they are quite cheap here locally. I was thinking of plugging it onto the TV or streaming to TV so I can see what it going on. The issue is that these USB microscopes are for windows ! 

[jaspert]

Plenty of sellers from HK.I'm looking at one with 2 Meg resolution with extrapolation to 5 Meg for about $50. No problem with software driver here. Good idea about streaming to TV.


Alex,

Hope your birthday wish comes true.
Let us know how you go  if you are the first to try it

[skippingjack]

Thanks Jasper,

My father in law is a radio engineer and I know that I couple of people that he works with have had good results with them.

I've dropped some hints but it's going to be next month before I know for certain.

[GP49]

Or, for those with the DIY bent (most of us here?) you can do something like this (lighting the subject needs to be done differently for examining styli, transillumination as in this example won't be suitable):

http://www.instructables.com/id/Build-a-USB-Digital-Microscope-in-60min-and-15/

[richard]

I've been using one for a few years.

extrapolation to 5 Meg

This is exactly what I don't' need.

What's important is to be able to see what is there, not what the system thinks should be there. The last time that I checked, there were only two USB microscopes on the market. Mine is the earlier version marketed by here originally by Mattel/Intel. I've found it best to toss out the horrible provided software and use, instead, the versatile, free, Irfanview (Windows). Native magnification is 200x, but I want to add another lens for more magnification. This will be tricky due to the glitzy deco plastic work. This microscope was last marketed here under the name "Blue Coral," and in Europe under a different name. The microscope's base is as horrible as its software.

Because this microscope has a standard built-in TWAIN interface, it can be used with any suitable image software. The built-in firmware makes it possible to bypass the obnoxious self-correction "features."

It's been very good for looking at used needles for obvious over-use. I need to get better illumination, especially if increasing the magnification. Being able to spot wear of the rounding on a parabolic tip seems pretty "iffy" to me. What's important to me is to be able to identify that point at which the diamond is beginning to "eat" the record grooves. Thus, being able to tell when it's time to replace the stylus. I believe that it's better to be able to recognize this rather than for the needle to get to the point where "Oh, yeah: your needle is worn out."

[wer]

Being able to spot wear of the rounding on a parabolic tip seems pretty "iffy" to me. What's important to me is to be able to identify that point at which the diamond is beginning to "eat" the record grooves. Thus, being able to tell when it's time to replace the stylus. I believe that it's better to be able to recognize this rather than for the needle to get to the point where "Oh, yeah: your needle is worn out."

But how do you recognise this point where it starts eating grooves (if not by a flat spot on one or both sides of the tip)?

[richard]

But how do you recognise this point where it starts eating grooves (if not by a flat spot on one or both sides of the tip)?

Flatting on one or both sides can be difficult to spot at the beginning of visible wear, especially on a parabolic tip. But that's what I look for. I do my best to imagine the un-worn curve, and then see if there's any visible deviation from that mental image. I have a few drawings and photos that I try to remember for comparison.

Looking at the tip as a shadow image is easiest to work with. In other words, I illuminate the tip from underneath so that the diamond blocks the light. This presents me with the best contrast instead of the nicest view of the diamond. And this has been the method used by the professionals that I've known about in the needle business when they evaluate tip condition and alignment..

Most people replaced their needles after they were "worn out." This just won't do if we're to preserve our records. I use the microscope to screen styli in unknown condition. Perhaps an even better method is as follows:

1. I get out a record that I hate. This is easy. For example, "Battle of the Great Central American Polka Bands."
2. Listen to the record as much as I can withstand.
3. Play more-or-less of the record ten times with the sound off..
4. Listen to it again and evaluate the degredation.

It helps for the record to be well-cleaned so that I'm not evaluating damage caused by dirt.
If I like the music, I should be taken for medical evaulation.

[wer]

I use just enough light to enable me to focus on the tip, then i shine an LED lamp from the side and as much from the top as the microscope will allow me. Any flat spot will reflect this light, and the diametre of the reflected light indicates the size of the flat spot.

[jaspert]

Thanks for the tips.
My main reason for considering one is for checking the styli as I have quite a few cartridges and some of them are used ones from Hifido and Yahoo Auction with unknown past history.

[ianm0]

I have done it with good results. Caveat: needs lots of patience to set up. A picture I took for my newly rebuilt cartridge:


I used an LED torch as my light source. At 200X, you microscope is at about 2 cm from the stylus. Extreme care must be exercised when moving the microscope around to avoid damage to cartridge. The tripod supplied with microscope is next to useless. Need a good photo tripod.

[richard]

I'm confused, Ian.

What microscope did you use?

[wer]

Interesting picture, is that a sapphire/ruby cantilever? Never seen one before.

As for spotting eventual wear on the needle, i would not know how and where to look with this kind of picture

[ianm0]

What microscope did you use?

It's a cheap USB 2M pixel microscope bought from ebay. Plenty floating around. Caveat: If you are using Windows 7, make sure it says Win 7 compatible. Driver will be automatically downloaded upon installation even not available from accompanying CD.

BTW, Werner,  that ruby cantilever and line contact stylus are from Soundsmith.

Maybe I should share a few words of wisdom I got from Soundsmith: the correct industry specification for SRA is 2 deg - not 92 deg. We have all been misled by guru reviewer(s). Also setting SRA visually for this kind of stylus is a bit tricky. See: http://www.audioasylum.com/audio/vinyl/messages/92/927670.html.  I am very grateful to Mr Peter Ledermann's generosity when it comes to advice even long after I received his retips.

I tried to measure SRA in the photo below:               


Ignore the text "Perfect SRA". Actually it measures 3-4 deg instead of 2 deg. Need to adjust arm height to change SRA. But beware, tracking force must be re-adjusted with even slight change of arm height. 

Ian