[orthobiz]

I embedded a question about this recently in an unrelated thread. Thought I might get more answers with a separate query.

Anybody using a USB microscope to achieve the proper SRA? I have a Macintosh computer and it seems like an intriguing idea to help with setup. If so, which microscope have you used? Or is it just hype and unnecessary?

Paul

[Wayner]

I have been looking at these:

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

Wayner

[Sonny]

I have been looking at these:

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

Wayner

that's not a bad price, did you buy one wayner?

[Wayner]

No I didn't, yet. I've been able to set my camera on a tripod and use my zoom mode to get a really close shot, but I am thinking the scope would just make it all the more easy.

Wayner

[orthobiz]

I forgot, did you post a pic off your regular camera? I know you're really into angles and measurements, did you superimpose an angle on your picture to ensure accuracy?

Paul

[Wayner]

I printed it out and drew a line thru the stylus, then measured the angle with a protractor. I then made adjustments knowing that for a 9" tonearm, 1° is about 4mm of VTA adjustment. Of course with some of the tables I have, you simply can't get there with just VTA, because 1) you run out of tonearm shaft to raise, and 2) your cuing lever is probably going to get in the way.

That then takes you to an alternate, and perhaps less desirable trick of tipping the cartridge in the head, using shims. Maybe we could talk Bill Berndt into machining some 1 or 2° shims for just this very purpose.

Earth to Bill.........


Wayner

[TomS]

I just saw "der tonearm's" ad on A'gon for this one, a mere $348 

http://app.audiogon.com/listings/uni-scope-microscope-new-for-stylus-and-cartridge-align--3

[neobop]

I have been looking at these:

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

Wayner

Wayner you come up with the best deals. That's pretty cool. I saw one that goes from 5 to 400X. You could not only use it for SRA, but also for stylus inspection. 400X would be enough to check for wear on even the smallest tips.

Perhaps you could have a target and view it right on your PC. Line it up with the record and at 92o.

For stylus wear you would need two high intensity lamps, one on either side of the stylus.

http://www.dealextreme.com/p/portable-usb-2-0-25x-400x-cmos-digital-microscope-with-8-led-illumination-black-70709

[Sonny]

I am thinking about getting one myself...my eyes are just not as "trusting" these days, but I ordered a digital scale from them over a month ago, they shipped it two weeks ago and still waiting for it.  No tracking or nothing with the free shipping.  Note that it's coming from China!

[Berndt]

Earth does call on occasion...
Tuan, Peter has the usb scope.

[orthobiz]

I know nothing about the scopes but I'll bet the "400x" scopes have digital enlargement that will probably not do the trick.

Paul

[coverto]

I am thinking about getting one myself...my eyes are just not as "trusting" these days, but I ordered a digital scale from them over a month ago, they shipped it two weeks ago and still waiting for it.  No tracking or nothing with the free shipping.  Note that it's coming from China!

I would counsel patience - I bought one of those digital scales from them a while back and it took a while, but it did eventually arrive.

[Wayner]

I had a better picture then this one, but I can't find the file:




w

[orthobiz]

Interesting, Wayner, but I wouldn't feel comfortable measuring off that picture. I understand this wasn't the best photo you took.

I posted this same question on the Linn LP12 website, a great bunch of audiophiles who will agree/disagree about how the most subtle alterations make huge differences. For instance, they torque the screws precisely, know which side of the felt mat sounds better, dustcover up or down, shimming the outer platter with respect to the inner platter for perfect central alignment, etc.

So far little interest there..."just make the arm tube parallel and enjoy the music." I was a bit surprised, maybe it's an anti-Mikey Fremer attitude...

Paul

[Devil Doc]

Interesting, Wayner, but I wouldn't feel comfortable measuring off that picture. I understand this wasn't the best photo you took.

I posted this same question on the Linn LP12 website, a great bunch of audiophiles who will agree/disagree about how the most subtle alterations make huge differences. For instance, they torque the screws precisely, know which side of the felt mat sounds better, dustcover up or down, shimming the outer platter with respect to the inner platter for perfect central alignment, etc.

So far little interest there..."just make the arm tube parallel and enjoy the music." I was a bit surprised, maybe it's an anti-Mikey Fremer attitude...

Paul

I'm no apologist for Fremer, but in his DVD he pretty much says the same thing.

Doc

[catastrofe]

I just saw "der tonearm's" ad on A'gon for this one, a mere $348 

http://app.audiogon.com/listings/uni-scope-microscope-new-for-stylus-and-cartridge-align--3

A quality USB scope will probably cost around $200 - $250 based on my research.  Sure, you can find units for ~$50, but I'd be highly suspect.  In addition, it's difficult to determine whether most units will work with OS X.  Rarely do the specifications state anything other than Windows.

Dertonarm's price is probably not too unrealistic, given shipping from Germany, the CNC'd stand, etc.

[neobop]

The only thing really good about the Uni-Scope stand is it allows you to use it with the $800 Uni-Protractor.
http://app.audiogon.com/listings/uni-protractor-set-the-tonearm-alignment-new-w-4-templa

This is a device for rich guys who can't figure out how to use a regular protractor. The supplied magnifier is subject to the same parallax error as any other magnifier. The first photo in the ad proves that.  Anyone can buy a linen magnifier on fleabey for around $8. They're stand mounted magnifiers, available in various powers.

The CNC stand is useless for SRA. There's no provision for setting up at 90o from the stylus or cantilever to eliminate this same angular error. I don't know about the zoom feature on the Chinese microscope, but you don't need anything remotely close to 400X for SRA. Using a magnifier in these applications requires multiple views with any kind of magnification.  There's no guarantee that the plane of the magnifier will be perfectly aligned to the stylus and you're viewing at the perfect angle.

For stylus wear inspection, it might not matter if the optical magnification is 200X and the rest is PC.  200X is enough to check almost every stylus. It's the additional lights that could be problematic and have to be rigged up for any stylus microscope. Anyway, they have another one with 900X.

[Wayner]

To get the ° symbol, use alt 248 and it will come up.

Paul, I've been designing for 35+ years, so I'm geared to work on crappy material. There is a bit of skill required to dissect the stylus with a line, then determine what is the plain of reference. You will have that same problem with the scope.

As Neo and others have pointed out, this technique is only the first step at dialing in the 92° rake angle. You need to view your stylus, with the stylus in the groove to find out where you are. Some stylus assemblies might be the other way and from the beginning, you are too high. You might have to lower the tonearm to get to the desired angle. What if your stylus measured 89°, or 94°?

If it was 94°, you'd have to lower the VTA by 8mm (.314"). If it was at 89°, you'd have to raise it 12mm (.472"). Those are numbers for a 9" arm. If you have a 10.5" arm, like on a VPI, the distance would be even more (I need to do the math on that one).

Ultimately, the vision part is step one in the process, but the ears have to be the final judge.

If it was easy, everyone one would do it.

Wayner

[orthobiz]

I'm no apologist for Fremer, but in his DVD he pretty much says the same thing.

Doc

Although the DVD was probably made before the Wally Tools guy showed Mike the light, so to speak...

Paul

[Delacroix]

checking back in --- anyone have an update on a usable scope that has proved worthy?