Michael Fremer discusses VTA, SRA in June 2010 Stereophile.....

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Wayner

This month's issue of Stereophile has Mr. Fremer discussing SRA is some detail. To sum it up, he suggests a 92 degree angle (see my illustration below) to take advantage of maximizing contact area and reducing FM distortion.

 

I have several questions about this and I hope Mr. Fremer joins in the discussion (he is an AC member).

Have you read the article and what do you think?

Wayner

sts9fan

That article was over my head.  It also has me considering dumping the vinyl.  I just want to play music man. 

BobM

One problem, with some line contact and Shibata stylus cuts you can't just go with the apparent vertical eyeball of the diamond in the groove. The contact areas are small and thin and sometimes cut on an angle. It's those "line contact" points that need to be in a proper orientation to the ripples in the groove.

This could be a good starting point, but the ear (or an oscilloscope) is still the ultimate judge of when it is properly aligned.




chosenhandle

I (and a friend) just used a USB microscope to set the SRA of my cartridge (line contact stylus). Once I set the angle to 92 degrees I was able to fine tune the angle very quickly (I have a Triplanar with VTA on-the-fly). I think I settled on about 91.5 degrees. The fine-tuning was audible and pretty straight forward for 2 people to do.

The thing that stands out to me is that my cartridge is no longer "tail-down". 92 degrees really tips the tail up on my cartridge. However, once dialed in, detail and focus was substantially better.

An interesting side-note is that VTA is 22 degrees to get the SRA at 91.5 degrees. I have always used the 20 degree cantilever angle rule-of-thumb in the past. That assumption appears to be wrong. Now that we have inexpensive tools like USB microscopes, measuring SRA and VTA are can be easily verified.

In the end, it is about the sound. I was simply surprised by how wrong some of my assumptions were!



Napalm

[...]Have you read the article and what do you think?

No and I wouldn't bother reading it other than for pure fun. Not since he has discovered that you can "demagnetize" vinyl and the effects are audible. I wouldn't loose sleep on anything he could ever say again.

Nap.

BobM

No and I wouldn't bother reading it other than for pure fun. Not since he has discovered that you can "demagnetize" vinyl and the effects are audible. I wouldn't loose sleep on anything he could ever say again.

Nap.

Have you tried it? Can you speak from experience or only from textbook-logic?

I can speak from experience and can say ... no it didn't make any audible difference to me on my vinyl. But similarly there should be no effect on CD's and it clearly made an audible difference there.

Surely I wouldn't take anyone's opinion as fact until I verify and validate it on my own, that means Fremers, Pearson's, or yours.

thegage

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No and I wouldn't bother reading it other than for pure fun. Not since he has discovered that you can "demagnetize" vinyl and the effects are audible. I wouldn't loose sleep on anything he could ever say again.
Nap.
Yup, wouldn't want to actually try something before having an opinion about it. Nap.

Back on topic, a similar discussion from AA a bit back, and a method to DIY:

http://db.audioasylum.com/cgi/m.mpl?forum=vinyl&n=829896&highlight=

Napalm

Yup, wouldn't want to actually try something before having an opinion about it. Nap.

That's exactly what my clairvoyant neighbor keeps telling me. Unfortunately she doesn't offer any free demo.

Nap.  :thumb:

Wayner

As a designer, I have several problems that the article talks about. First, I do not have a $250 USB scope to look through. Second of all, I doubt there are many who can see 1 degree of difference with their eyes.

Now I have some questions. How do we know that a cartridge manufacturer has or has not designed this into their cart? Grado, for example clearly states that the face of the cartridge (also in azimuth) must be 90 degrees to the record surface. Does that mean that Grado decided to build the cantilever with a 22 degree VTA (92 degree SRA) into the assembly and at a particular VTF?

Mr. Fremer may have also made a mistake in his article, saying that some folks would add extra (beyond recommended) weight to the tonearm, but that would work in the wrong direction, reducing the SRA as the cantilever would sag with the extra weight. Kind of like leaning on a rake.

I do think it may be of some importance to lean the stylus as has been suggested. It's the consumers ability to accurately measure and the tonearms ability to just plain get there, that bothers me.

As an example, as mentioned in the article, to change the SRA angle by even 1 degree would require you to raise your tonearm VTA by 4mm. That is .157" or about 5/32", assuming the SRA is at 90 degrees at the recommended VTF setting.

This opens a complete can of worms. The consumer is going to have to either get a scope, or call the cart manufacturer and try and get some technical info on their particular cart.

So my question to Grado would be, so when the cart VTF is set at 1.6 grams, where is the stylus at in relation to vertical, when the arm's VTA is set at vertical (that it's parallel to the record surface)?

Yikes!  :o

JoshK

That article was over my head.  It also has me considering dumping the vinyl.  I just want to play music man. 

I can sympathize.  And you wonder why Gen X'ers only want to listen to their mp3s on their Ipods? 

Secondly, I'll admit, I have no clue what SRA stands for. I know VTA and VTF.  But does everyone who would read this thread?  Not exactly inviting for would-be enthusiasts.

Sorry, rant mode off...

hesson11

Don't blame Mr. Fremer for the 92˚ thing. He was merely reporting what John M. Risch and Bruce R. Maier discovered in their groundbreaking article, "More Than One Vertical Tracking Angle" in the March, 1981 issue of "High Fidelity" magazine. That's right: Nineteen-freaking-eighty-one! Accompanied by ample documentation consisting of distortion measurements, the article concludes:

"Proper hi-fi set-up should therefore concentrate on cartridge adjustment that has the tip of the stylus pointed 'back' toward the tonearm pivot and the top of the stylus tipped 'forward' so that the contact SRA face is 92 degrees between the stylus and the record surface. Such alignment will at least approximate correct SRA."

Mr. Risch, co-author of the article, re-emphasizes his thoughts in this 1999 post at Audio Asylum:

http://www.audioasylum.com/audio/vinyl/messages/1240.html

This isn't news, folks. Nor does it seem to be a matter of opinion, if the measurements of Risch and Maier are given credibility.

One interesting note: During Michael Fremer's cartridge-setup seminar at the Axpona/Jacksonville show, I asked him whether you're better off with a traditional elliptical stylus if you're not sure you can align your fine-line stylus to the 92˚ SRA. His response was yes.

BTW, SRA = stylus rake angle, the angle between the stylus vertical contact area and the surface of the record.

All that being said, can I align the SRA of my cartridges to 92˚? No. Or if I can, it would purely be by luck. To my mind, the only way to do it would be to use the microscope and software that Mr. Fremer describes in his article. I don't think I'm going to do that. And all of this has me wondering about my next cartridge purchase: Do I really want a fine-line/MicroRidge/Shibata, etc. stylus? Maybe not. But plenty of people seem to enjoy theirs, and the chances that they are properly aligned for SRA is pretty small.

-Bob

Wayner

I don't think one person here said it was "new information". I think there have been discussions on this topic before, perhaps not being so blunt to spit out an exact number, like 92 degrees. The discussion centers more about how would one get his/her stylus in that position (with confidence and accuracy) without spending gobs of money and/or time doing so. And at the same time, is all the fuss really worth it.

I've heard cartridges that had the tonearm's ass up in the air, and I thought they sounded schrilly. I also wonder how much of this is "theoretical" and how much is actual. I sometimes wonder if those who have jumped on the 92 degree SRA bandwagon have thought about the cutting tool at this angle, with material constantly flowing by. Like taking your finger straight up and down and drawing a line in the sand. Now angle it 2 more degrees and draw another line. Are they the same (in practical terms), is it better to just do this by ear. Or should I start tooling up 2 degree wedges for those with fixed VTA.

This also brings up the point with Rega owners. If you need 2 more degrees, those shims you've been using aren't even gonna get you close.

Wayner  :D

Ericus Rex

Is a thick 200 gr record enough lift to totally negate the 2 degrees compared to a thinner earlier record?

analogcorner

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Some of the comments here demonstrate why I tend to stay away from online "communities." The smirky, snide, foolish comments are toxic.

Fortunately there are a few level heads including Wayner and Hesson11---and not because they agree with me.

What I reported in this month's Stereophile was not my "opinion." It was based on empirical research done, as one of the level heads here reports, complete with illuminating graphs.

The person who snidely remarked that all of this is to be dismissed because I reported the audible differences from demagnetizing vinyl is an idiot. There, see? I can be as dyspeptic here as anyone. The effects of demagnetization have been heard and confirmed by Tim DeParavicini, Paul Stubblebine, John Atkinson, Roy Halee (Paul Simon's long time engineer), Classic's Mike Hobson and EveAnna Manley among others. So before you write dismissively about this, have a listen why don't you?

Back to SRA/VTA. If you don't want to bother with this, then don't. Just play your records and enjoy.

I'm surprised that Wayner, a "designer," has a "problem" with a $250 tool. I'm not sure what he designs, but that's the cost of a good soldering station and a good digital voltmeter. So what's the "problem?" And yes, if i wrote that adding VTF (tracking force) increases SRA, I meant to write that it decreases SRA...

The approximately 92 degree setting is correct for any stylus because it reflects the rake angle of the cutter head. Cutter heads are beyond 90 degrees to allow for the cut lacquer to be vacuumed from the surface....

One of the issues we're now discovering is the variations in how the styli are affixed to the cantilever. A cartridge manufacturer can tell you the correct VTA and you can set it by eye fairly easily with a piece of glass etched with various angles (20, 21,22,23) but sometimes the stylus is not affixed correctly to the cantilever as can be seen under the microscope--there are variations of more than a few degrees in different samples of the same cartridge.

The research demonstrates that SRA is more critical sonically than VTA.

 The Dino-lite microscope comes with software that allows you to precisely measure SRA, there's no guesswork involved. Unfortunately, the photo used in the story was the wrong one...an editing/layout error. That was not an Ortofon cantilever. The photo that was supposed to be used, shows the software lines drawn, noting the angle...

And yes, as someone mentions, the SRA is not necessarily a center line drawn through the stylus. The photo in the story of an oversized model of Ortofon's replicant stylus shows that...in that case, it's the rear surface of the stylus that needs to be 92 degrees...

If you don't want to bother with the microscope and are using a fine-line, Shibata etc. you can do pretty well with a jeweler's loop and a bright light---just to get it close to 92 degrees once you know the contact surface you need to align at 92 degrees. Once you get it close you can adjust by ear.

The problems come when you don't begin adjusting close to where it belongs. Then the odds of finding the right setting diminish.

I can tell you that when I reviewed the Ortofon A90 I didn't have the microscope, nor had I read the Risch article (or I'd read it back in 1982 and forgot!). When I re-installed the Ortofon and set SRA with the microscope, the 3 dimensionality and image stability greatly improved...

Finally, it was not my intention to open "a can of worms."

Rather, it was my intention to offer useful information for those who wish to optimize vinyl playback and make a meaningful (I'd say enormous) improvement to their listening experience...I found the improvement significant...

Don't bother if it's too much bother...and if you don't want to bother, i suggest staying away from the severe stylus shapes...there's no point in spending extra for one of those if you're not willing to work to optimize the performance they're capable of giving you.

Finally, please try listening to a before and after record demag before you make sarcastic and snide comments dismissing it. No, you can't demagnetize plastic and that's not what's being demagnetized....

Thanks for listening..

sts9fan

Quote
The person who snidely remarked that all of this is to be dismissed because I reported the audible differences from demagnetizing vinyl is an idiot.

Very nice.  Thanks for stopping by.

jsaliga

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I find all of this rather interesting.  I can only speak for myself, but at this stage in my life I think I am done with the never-ending pursuit of "better sound."  I just can't quantify such an ambiguous goal.  I suppose my membership in the audiophile club will be cancelled.  :lol: 

I have a Ortofon Jubilee with a nude Shibata stylus.  I set my tonearm (a SME 309) up in accordance with the directions from the manufacturer using the supplied tools, and also followed the instructions from Ortofon to install and align the cartridge.  I am completely satisfied with the performance of my vinyl rig.  I am more of a believer in making changes to one's system to solve perceived problems or shortcomings.  If you don't perceive a shortcoming then there isn't one.  So I most certainly follow the axiom "If it ain't broke don't fix it."  That's not say that I haven't made changes out of curiosity, because I have done so in the past.  But it has lost a lot of its appeal over the past few years.

The effort needed to implement this might be worthwhile for some, and more power to them if they can find some sonic benefit from it.

--Jerome

BobM

Thanks Michael. I think you certainly clarified a few things on the alignment issue. I did find that attempting to set my SRA using a jewlers loupe and bright light made my tonearm look like a 1960's souped up sportscar with a severly raised rear end. It didn't sound right either. But it certainly did help me dial things in to a better degree using my ears.

The back end of my tonearm is definitely higher than it was before, and up a bit from parallel where I had it down more before I attempted to align SRA visually. I agree that it probably should be a good starting point, but the final arbiter is the good-old ear.

As for demag'ing vinyl - keep pushing the envelope (I know you will). There's always more to be learned than the scientific types will admit to, until of course it is published in some college textbook. Then the'll all jump on board and declare that Newton just didn't have the tools at hand or he would have known this was true long ago; even before vinyl was invened.  :thumb:


Napalm

Very nice.  Thanks for stopping by.

He just wanted to prove once again that The Audio Critic got it right many years ago:

http://www.theaudiocritic.com/back_issues/The_Audio_Critic_24_r.pdf

page 14 (PDF 15).

Nap.  :thumb:

BobRex

Very nice.  Thanks for stopping by.

Why the snide comment?  Napalm dismisses Mikey and the demag issue without ever mentioning any research debunking and in doing so fulfills Mikey's first comment regarding uninformed snide commentary.  Mikey returns fire, but then takes the time to report confirming experiences with differing parties (who I assume Napalm also thinks are suspect).

You on the other hand said this whole thing was over your head.  Mikey took the time to explain further - did you gain any understanding from this?

You may not like that Mikey returned fire, but I'm sure that Napalm is a big boy and can take it.

sts9fan

Why? Because this is not 'Nam, there are rules and personal attacks have no place here.