Stylus Zenith Angle: A Heretofore Neglected Set-up Parameter Considered

How did this one get neglected? Take a look at the photo supplied by WAM engineering. It shows a stylus in a cantilever. Notice it has been affixed into the cantilever at an angle instead of being parallel to the cantilever. If you use the cantilever to set the zenith angle on this cartridge, which is what I and everyone else recommends, the stylus will not be tangential to the grooves at the null points though it might accidentally be so somewhere else.

Ironically, if you have a tangential tracking tonearm, this cartridge will never be tangential to the groove at any point in its travel across the record surface!

At one point, for correct zenith angle set-up, we were instructed to be sure the cartridge body was lined up "squared" to the overhang gauge hash marks, but it eventually became apparent that cantilevers were not necessarily aligned with the cartridge body and of course if the body wasn't square you couldn't use the body as a guide anyway. So the instructions changed to "use the cantilever." That's what I have been recommending for years in my seminars.

At the same time I say "be sure to get a digital microscope because the odds are the stylus has not been corrected affixed in the cantilever in terms of SRA."

And I say, 'be sure to set azimuth electronically and not by adjusting the cantilever to be perpendicular to the record surface, or the head shell parallel to the record surface."

Why? Because the odds are the stylus has not been inserted perfectly into the cantilever in terms of being "45/45" to the groove center."

How then could I and everyone else not have considered that the stylus might also be misaligned in terms of zenith angle? I don't know. Maybe out of sight out of mind. I just never thought about it. Until this image arrived in an email.

But now, what to do about it? Obviously using the cantilever to set the zenith angle isn't 100% reliable but let's say you look under a microscope and see this kind of picture. Do you try to compensate for the angle by twisting slightly the cartridge to purposely misalign the cantilever zenith angle in the hopes of perfectly compensating for the manufacturer defect? Can it possibly matter when you and I both have gotten excellent results without considering any of this? Can we all get even lower distortion and better sonic performance by making this correction?

Going forward I'm going to inspect review samples, assuming my 200X microscope will magnify sufficiently. I think if you have spent more than $1000 on a cartridge you are entitled to one that has been properly manufactured in this regard and I'd return it unused rather than trying to compensate in the set-up for the problem. If you've spent many thousands of dollars and find this defect, I'd be pretty ticked off about it.

Your thoughts?

COMMENTS
vince's picture

Michael;

You raise some questions of manufacturing.

Everything realized by man is subject to error.  The question isn't, "does an error exist"?  It does.  Rather it is, "how much error is acceptable"?  

To me it appears that the stylus tip is misaligned with the cantilever by roughly one degree.  

- How much error is incurred when we align a cartridge on the tonearm using commonly available alignement tools?  

- How does this error compare to the error seen above?

- Does the manufacturer control this facet of production (they should!)?  

- If so, what is the spec? 

- Does this part meet spec?

- How does their ability to measure the alignment error compare with the error seen above?  Or, what is the error in their measurement system?

- Is a one degree error acceptable?  

- Can we hear it?

 

Some thoughts

 

Vince

Michael Fremer's picture

Of course perfection is difficult to impossible. However setting these parameters when aligning a cartridge can and should be done greater than 1% tolerance if it's done with care. That's on the user end. Of course manufacturers can't achieve perfection so I think it needs to be seen in the context of the cartridge's price and how far off it is from perfection.

In this case it is around 1 degree but what about other cases? I have seen $5000 cartridges with 87 degree SRA when the arm is parallel to the record surface. That is absolutely unacceptable but until we started looking at these things under the microscope we were unaware.

Perhaps 1 degree isn't too far off for a moderately priced cartridge but who knows what else is out there? Now that I've seen this I will be looking! The Zenith angle misalignment equivalent of 87 degree SRA would be not just bad sounding but groove damaging.

Devil Doc's picture

If I spent $500 on a cartridge, I'd expect it to be right.

missouricatman's picture

I agree getting the stylus tip properly aligned is the end objective, so sure, if you've got the ability to check that it's been set right by the manufacturer, I'd say go for it.

But the next step will be to try and determine if the shape of the stylus on the left side is truely mirrored on the right and at that point, I think we're splitting things smaller than a hair.

Vino Bambino's picture

Oops see below....

Vino Bambino's picture

As consumers discover better systems to check the manufacturers craftsmanship these types of issues will continue to be more prevalent but hopefully it will inspire/challenge the manufacturers to improve their processes and inspection procedures. To think not that long ago something like this would have gone unnoticed and the owner may have not recognized that this cartridge was capable of a higher level or performance or conversely, criticized the performance because the perception was the setup was done properly.

I believe we have gotten to a point where our setup technology has evolved to a level of sophistication that will provide more enjoyment of a product but may very well be the impotence to cause more headaches for the manufacturers! Will it drive up cost? I hope not. Will it help drive improvements in manufacturing procedures; I hope so, for everyone’s sake!

homersoddishe's picture

CD's and digital downloads only for me from here on out!

 

I kid, I kid.  I kid, because I love.

gofar99's picture

Hi,  Is it possible to set the angle with a dual trace scope and a test record?  Would this get around possible angular errors in the stylus?

Good Listening

Bruce

Michael Fremer's picture

Next time I get one with this defect I will find out!

FormatOmnivore's picture

...yet another thing to worry about!

Jim Tavegia's picture

Just what audiophiles need is something else to be worried about. This is when a spherical stylus doesn't seem like such a bad idea.  lol

A Shibita stylus or one of the fine line types could make this even worse. But this raises a question for me.  I know that Grado takes a group of carts and the ones that measure better get an upgrade as to model and price.  I am guessing that is mostly due to a better frequency response test?  Maybe?  It also may be due to a straighter catilever and perfectly oriented stylus, but how would any of us ever know? 

Certainly those in the cartridge business must have higher resolution  scopes than you and should certaily be better able to mount a diamond properly, regardless of cost. I remember Shure making a big deal about the danger of buying an after-market replacement stylus from someone other than Shure as their QC was supposedly much better. 

AnalogJ's picture

I bought an ACE from Musical Surroundings through my dealer. It was so off by mere eye view I sent it back. How could something like that slip through quality control?

Doehmann's picture

"you can't fix what you can't see"!!!!

This applies to stylus alignment and if we are "going the full hog" in setup then we need to have an idea what the stylus is really set up like in SRA (Stylus Rake Angle), SAA (Stylus Azimuth Angle) and SZA (Stylus Zenith Angle)

Wally Malewicz of WAM Engineering has been pushing for tighter tolerances and a standard for alignment for many years.

His pioneering work in portable microscope tools for analog end users has given us all the ability to get SRA tolerances recorded.

This new work he is doing is taking that approach to its logical conclusion. SZA or Stylus Zenith Angle.

In conjunction with an oscilloscope and some quality alignment tools you end up closer to the original source material which is what the real objective is.

bluedelity's picture

Hi, could a rotary headshell be the perfect solution on this matter? No tracking angle, no antiscating, nothing to consider and everything that influenses the position is there. If tou want the social aspect of that, can be described as freedom!

Rudy's picture

I am hoping this exposé makes it to the stylus manufacturers.  We (the consumers) are watching.  I had a feeling that the last VN5MR stylus in my Shure cart was not as good as the previous replacements, and it turns out I may have been right--once I changed carts, the background noise I'd noticed in this particular stylus disappeared, and my records became as quiet as I had remembered them to be many years ago.

Considering how much I spent on my new cartridge (2M Black), I fully expect the stylus to be in perfect alignment.  If the diamond and cantilever are hand-assembled, there is no excuse for the diamond to be off-kilter: someone looking through a microscope should be observing the alignment of that diamond as they are assembling it, and unless they are being careless or lazy, there is no way they cannot notice that a diamond isn't lined up correctly.  If done by robotics, quality control would still need to be monitored.

Now I am really itching to see how the diamond is set into the cantilever on this new cart.  I would also be interested in someone pointing me to instructions on how to use an oscilloscope for alignment, as that would really take the guesswork-by-ear out of the equation and help me get this thing aligned to my satisfaction.

Rudy's picture

That 2M Black was so shoddily assembled that I got rid of it. The zenith angle was at least 2 degrees off, if not more. SRA was a bitch to adjust. And not only that, the stylus was cocked in the assembly so badly that it looked like my tonearm came loose and twisted to one side! I've had two Dynavectors since then. Both were meticulously assembled. I still have the XX2 and it runs circles around that crap Ortofon. Just shows you the difference between "in it for the bucks" vs. "craftsmanship."

Timbo in Oz's picture

to the cantilever.

This level of checking was something Martin Colloms used to do in the annual Hi-Fi Choice (UK) reviews of cartridges in booklet form.

It wasn't often way out but it can be. MFR's QC is human controlled!

After all what we are trying to do is to align the cartridge as a generator system / transducer to the cutter/transducer that cut the master.

SRA, VTA, null points and anti-skate/bias are just to get us close to that ideal.

The late Allen Wright's article on getting even closer is worth referring to. This has to be done by ear or with an X-Y signal (?) and a scope - or even a  disc with Lissajous signals on it - IIRC.

IME getting close is usually so much better than what the cuctomer had that I usually left it there. The next stage takes a lot longer - IME.

Been a good while now.

Tim Bailey

 

 

 

kensargent's picture

I think there might be a fundamental issue with the idea of "correcting" the stylus misalignment by countering it with intentional misalgnment of the cartridge body.  Specifically, if the cartridge body (and by association, the cantilever and the dynamic structure) are moved away from, for lack of a better term, static tangency, the symmetry of the cantilever's movement is forfeited.

In other words, you might get the stylus aligned to the groove across its' width, but the movement within the cartridge's motor structure is now assymmetrical, and surely not linear.  Perhaps some of our engineer friends might look at this, but I believe that the lateral excursion of the cantilever would be compromised to some sonically noticeable degree.

Let's face it: there are likely prolific QC issues in the cartridge arena.  If you doubt that, just look at a close-up photo of a recent test cart, and observe the rough edges of the body, or the bad glue joints.  But certainly, with the absurd pricing of some of today's cartridges, there is simply no excuse for the stylus not being aligned before the cartridge is shipped.

Michael Ivosevic's picture

Hello Michael

In my early, naive journey into this wonderous world of audio I purchased a used Rega P3 with RB300 arm and a middle of the range MC cartridge from an old and well regarded Dutch manufacturer. Even though this cartridge had a cantilever that was not aligned accurately to the body, I fell in love with it's tonality and while on occasions I could detect slight groove wall artifacts, it's good channel seperation gave me no cause for concern until, a couple of months after the warranty expired I started to notice a slight greying effect on the tracks I frequently used for system evaluation. I thought it odd and took a closer look at my cantilever/stylus, only then did I realise just how far out of alignment these components really were. I quickly learnt to appreciate the damage that occurs to precious records when this situation exists, I also came to understand the limitations in arm designs that do not allow azimuth adjustability to compensate for the poor quality control from cartridge manufacturers. All these years later I still have the cartridge and it still has the misaligned cantilever but now it sits more appropriately in an arm that allows azimuth adjustment. I use visual alignment of the catilever and stylus to the groove and aural assessment to arrive at a setting but it is all too fiddly, too time consuming, far too hit and miss and I suffer unwanted movement when nipping the cartridge into position. Maybe, if cartridge manufacturers are reluctant or don't know how to address Quality Control, they could produce tonearms with repeatable micrometric headshell adjustability and a means of locking the cartridge without imparting unwanted movement. In conclusion, I just want to add that I know of no other that carries the analogue flag as high and passionately as you and for that you have my respect and good luck with AnalogPlanet. 

Regards

Michael.I

Oksana's picture

I agree with kensargent. It seems like the cantelever is designed to be aligned properly and when it's twisted to make up for stylus misalignment, who knows how it affects the sound? He said it better, I just woke up!

orangeaudio's picture

I can send you some "nice" pictures from Lyra cartridges and rotated diamonds.

Greetings, Tom