USB Microscope Stylus Rake Angle

orthobiz · « **Reply #20 on:** 26 Nov 2012, 04:31 am »

No, but for less than 7 bucks I bought this:

Skque 45X Mini Pocket Microscope with 2 LED Lights

on Amazon. An interesting little microscope, analog, pure analog.

Has a viewing clear plastic guard on the tip and you can't really get close enough to see the rake angle. But it is cool to look at a stylus or some other thing you want magnified. Amazing how inexpensive it is.

Paul

orthobiz · « **Reply #21 on:** 26 Nov 2012, 04:38 am »

Also, I wasn't sure if this Fremer article was quoted before:

http://www.analogplanet.com/content/how-use-usb-digital-microscope-set-92-degree-stylus-rake-angle-sra

Paul

jimdgoulding · « **Reply #22 on:** 26 Nov 2012, 05:23 am »

Quote from: Wayner on 27 Apr 2012, 07:06 pm

I have been looking at these:

http://s.dealextreme.com/search/usb+microscope

Wayner

Nice link. Thanks.

WntrMute2 · « **Reply #23 on:** 2 Dec 2012, 01:37 am »

I used a $100.00 USB microscope to obtain this image. A little pixelated at the magnification I was using but good enough to measure the angle of the stylus without difficulty.
http://www.amazon.com/gp/product/B005P40OXY/ref=oh_details_o05_s00_i00

jimdgoulding · « **Reply #24 on:** 2 Dec 2012, 02:51 am »

Not shabby. I may invest in one myself.

neobop · « **Reply #25 on:** 2 Dec 2012, 04:26 pm »

Quote from: WntrMute2 on 2 Dec 2012, 01:37 am

I used a $100.00 USB microscope to obtain this image. A little pixelated at the magnification I was using but good enough to measure the angle of the stylus without difficulty.
http://www.amazon.com/gp/product/B005P40OXY/ref=oh_details_o05_s00_i00

From the link above, it seems this angle is measured from the centerline of the tip. Not so easy to ascertain. Is there software that measures this for you? You could measure the front and back angles of the tip and average them to get the SRA, but that would also require, at the least, some kind of protractor to superimpose over the image.

There's another problem. This picture looks like it was taken somewhat in front of the cantilever. In order to get a proper estimate, the camera must be exactly perpendicular. I guess this can be useful for getting in the ballpark, but seems like a lot of trouble for something you'll have to tweak in by ear, anyway. Nice pics, BTW.
neo

jtwrace · « **Reply #26 on:** 2 Dec 2012, 04:29 pm »

Quote from: neobop on 2 Dec 2012, 04:26 pm

Is there software that measures this for you?
neo

Yes, it's built into most good USB Scopes.

WntrMute2 · « **Reply #27 on:** 2 Dec 2012, 05:54 pm »

Quote from: neobop on 2 Dec 2012, 04:26 pm

From the link above, it seems this angle is measured from the centerline of the tip. Not so easy to ascertain. Is there software that measures this for you? You could measure the front and back angles of the tip and average them to get the SRA, but that would also require, at the least, some kind of protractor to superimpose over the image.

There's another problem. This picture looks like it was taken somewhat in front of the cantilever. In order to get a proper estimate, the camera must be exactly perpendicular. I guess this can be useful for getting in the ballpark, but seems like a lot of trouble for something you'll have to tweak in by ear, anyway. Nice pics, BTW.
neo

I disagree, this cartridge is a Benz Glider S. It has a fine line stylus and the appropriate facet is facet 38 or 39 ( I can't remember right now). But that is the correct one I measured. Also, the camera was as perpendicular to the proper facet as possible. What makes you think otherwise?

I arrived at this position by ear BTW, I used a Charles Mingus album that had a difficult to clearly identify a "shushing" sound. I started as low as possible and raised the arm in 0.5mm increments until the sound coalesced into a cymbal ride. The above picture is documentation as to that setting. The picture was taken over a year after I set the arm.

Interestingly, I just took a picture of a Sumiko Blackbird with an elliptical stylus on a very different set-up. This is on a Terminator T3 arm. Once again, I set it by ear and as close as I can measure, It comes out to very close to the ideal 92 degrees. Both arms are very close to level when the SRA angle is close.

jimdgoulding · « **Reply #28 on:** 2 Dec 2012, 06:05 pm »

Question. Is that stylus in the top photos supposed to be set up like that? My reading of proper set up is that one is to draw an imaginary line straight up and down thru the center of the stylus and adjust the line, not the body of the stylus. Thanks in advance for your reply.

neobop · « **Reply #29 on:** 2 Dec 2012, 06:43 pm »

Quote from: WntrMute2 on 2 Dec 2012, 01:37 am

Seeing the front of the cantilever above the diamond, it looks like the camera angle was from somewhat in front. I don't understand what you're saying about the facet. The link says that the centerline is what's measured.

I don't do any of this, and from your last post it seems that you're just verifying what you do by ear. That's what is important and I think this is an aid for those unfamiliar with setting VTA/SRA, or to get an estimate or preliminary idea. I don't even subscribe to the notion that 92* is necessarily right, or right for all records.
neo

orthobiz · « **Reply #30 on:** 2 Dec 2012, 07:19 pm »

Neo,

I too thought the pic was at a bit of an angle. Mainly because there is something hook-like about the stylus itself.

But I am absolutely NOT an expert!

Paul

WntrMute2 · « **Reply #31 on:** 2 Dec 2012, 08:02 pm »

Quote from: jimdgoulding on 2 Dec 2012, 06:05 pm

Question. Is that stylus in the top photos supposed to be set up like that? My reading of proper set up is that one is to draw an imaginary line straight up and down thru the center of the stylus and adjust the line, not the body of the stylus. Thanks in advance for your reply.

Facet 39 is what I am measuring. Not the centerline of the stylus. That angle is theoretically the one that is supposed to measure 92 degrees. This is a gyger type stylus with the angle set at the leading facet (39). I still believe the angle I have the camera is very, very close to square on. You don't see any of the face of the shank on the cantilever or any of the backside of the square stylus above facet 39. The slight hook shape is related to the gunk I didn't get cleaned off at the junction between the stylus and glue holding it on.

jimdgoulding · « **Reply #32 on:** 2 Dec 2012, 11:21 pm »

Gyger stylus. Understood. Thanks.

vinyl_lady · « **Reply #33 on:** 4 Mar 2016, 02:11 am »

At last year's RMAF I attended Michael Fremer's seminar and was convinced to buy a USB microscope to check the SRA of my Lyra Atlas cartridge. I bought a Dino through Amazon (recommended by Michael and a stand. Last December, when I had a few days off from work, I decided to give it a try. I followed Michael's article posted on Analog Planet (http://www.analogplanet.com/content/how-use-usb-digital-microscope-set-92-degree-stylus-rake-angle-sra#EGYJ4korBAc1FHE1.97), and it was a huge help for me. Not sure I could have done it without his article. It was time consuming and there was definitely a learning curve in using the USB microscope and getting it to focus correctly, but after a few tries, I was able to get some good pictures.

The first one showed the SRA at approximately 94.591.

I listened, then adjusted the SRA by making small adjustments to the VTA on my SME 20/2, listened and took another picture, closer to 92, but not close enough for me.

I made another small adjustment to the SRA and took another picture. The SRA was approximately 92.991, much closer to 92 than where I started and the music was more in focus than it was before and sounded better.

I listened again and made another small adjustment in the VTA (about 2 mm). Listened to several songs I am very familiar with, like what I heard and called it good. By this time I was tired of getting the stylus in focus on the USB microscope. I figured I had to be pretty darn close to 92 given my inexperience with the Dino and using their drawing and measurement tools.

Most importantly, the music sounds better with more detail, focus and balance than before. It was worth the time effort and cost of the USB microscope.

Laura

Letitroll98 · « **Reply #34 on:** 4 Mar 2016, 02:47 am »

Hi Laura. Having now heard the nature and scope of the improvement, how close do you think you could get by ear alone? Another way to say it would be is there a spot where it just locks in?

vinyl_lady · « **Reply #35 on:** 4 Mar 2016, 03:22 am »

Quote from: Letitroll98 on 4 Mar 2016, 02:47 am

Hi Laura. Having now heard the nature and scope of the improvement, how close do you think you could get by ear alone? Another way to say it would be is there a spot where it just locks in?

Before I measured I thought it sounded pretty good. I made a couple of adjustments here and there as I listened and maybe I could have found the place where it "locked in" by ear if I was willing to spend the time listening, adjusting, listening and adjusting. Fremer convinced me that given what I paid for my cartridge I should spend a couple hundred bucks on a USB microscope and stand and get it as close to 92 deg as I could. I don't know if I could have gotten there by listening--maybe, but I do know that everything sounds more focused with more detail and balance now than it did before. I also know that it got a little better each time I adjusted to get closer to 92.

orthobiz · « **Reply #36 on:** 6 Mar 2016, 03:11 am »

Cool pics, Laura. Which Dino did you get?

Paul

vinyl_lady · « **Reply #37 on:** 6 Mar 2016, 06:15 am »

Quote from: orthobiz on 6 Mar 2016, 03:11 am

Cool pics, Laura. Which Dino did you get?

Paul

Hi Paul,

Thanks and I hope you are doing well. I bought the AM 3113, the one Michael recommended.

Did you see the two Move albums I found?

Laura

orthobiz · « **Reply #38 on:** 6 Mar 2016, 01:31 pm »

All is well here, thanks, Laura. Just saw the Move albums now. The Move only had 4 records, one pseudo-psychedilic pop, one heavy rock, one heavy rock, one even more pure pop. Love them.

Looking On is, of the four, the most "for fans only" record. Feel To Good plods along and keeps restarting with the bashed Bev Bevan drum. I love it all (as you know).

I just bought a mono cart and may get the USB microscope in the future...

Does the 92 degrees apply to mono styli??

Paul

Wayner · « **Reply #39 on:** 6 Mar 2016, 08:37 pm »

Hopefully, every time you change your VTA, you re-align your cartridge........It is the hypotenuse of a triangle and as you raise or lower the back end of the toneram (from a previous cartridge alignment) you have now made the pivot to stylus distance shorter.

What you might think is a change from adjusting the VTA (SRA), you may have just been experiencing the sound of something different, not necessarily better, just different.

I have re-thunk the entire SRA debate. I have to ask myself why I would not want to have the contact surface of the stylus be anything but vertical? Any slant of the stylus adds a time element to the playback, as any other contact angle other then perfectly vertical is going to smear time together during playback.

A stylus "rake" angle was used during the dead wax cutting process, much like a machinist would add "kerf" to the cutting tip of a lathe. This "kerf" simply kept the cutting tip from chattering (which causes skip). The modulations in the vinyl can be nothing other then completely vertical in nature (from a side view) or the vinyl would not cleanly pull out of the the stamper.

'ner