Hi, I while ago I read of the release of a 4th cartridge alignment set up gauge. If I am not mistaken it only had 1 nul point across the arc. However I have searched the we & cannot find out any info on it, even what is it called.
Cheers for any info.
Cheers for any info.
There are single point alignment gauges but I wouldn't use one. There are too many assumptions inherent in a single point gauge to be sure it is suitable for anything but the very turntable it was designed for.
The basics of tonearm alignment haven't changed since the the size of an LP was standardised. However recent researchers have looked at human error in using alignment gauges. It turns out that an error of judgement in one direction impacts on sound quality much more that the same error of judgment in the other direction. There are now setup gauges that take into account the tolerance incurred by human error. I highly recommend the Walter E Schön protractor, which I have used for the past 10 years for professional turntable alignment.
http://www.weschoen.de/schoen-schablone.html
The basics of tonearm alignment haven't changed since the the size of an LP was standardised. However recent researchers have looked at human error in using alignment gauges. It turns out that an error of judgement in one direction impacts on sound quality much more that the same error of judgment in the other direction. There are now setup gauges that take into account the tolerance incurred by human error. I highly recommend the Walter E Schön protractor, which I have used for the past 10 years for professional turntable alignment.
http://www.weschoen.de/schoen-schablone.html
And in English -
The Schon cartridge alignment template - [English]
My own protractor is made from hardened thick plastic with a mirror and was recommended by UK "golden ears " .
This German protractor is good quality and costs (approx ) £54 (UK)
The Schon cartridge alignment template - [English]
My own protractor is made from hardened thick plastic with a mirror and was recommended by UK "golden ears " .
This German protractor is good quality and costs (approx ) £54 (UK)
I don't know any protractor is better than Mr. Hoffman's protractor app. I was benefited greatly from the app at the time I was using a pivot arm. Thank you, Mr. Hoffman! If you use the app, you may just align one point.
Conrad's Free Stuff
Conrad's Free Stuff
As I don't have Windows --MS-DOS I cannot install your link on my Linux system and no I wont be installing Wine and I will stick with favouring the German protractor .
Thanks for that! I couldn't find a link.
I came across Walter's paper when trying to work out why the very expensive ClearAudio Professional Analogue Toolkit with its single point protractor was giving results with high end of side tracking distortion on some turntables.
Professional Analogue Toolkit – clearaudio analogshop
All the chatter over cartridge alignment over the years has made my stomach turn.
What really matters is the end-of-last-track alignment.
THAT, particularly with an elliptical stylus, must be a perfect angle - stylus cantilever 90 degrees to the spindle - as a typical linear tracking arm would be.
Because at that point of a record, the high frequency modulations are the tightest.
So to best avoid sibilence and distortion of that "last song", this is important.
What's never mentioned is the actual way records are cut, modulation-wise.
The other, outer bands of a record have increasingly "relaxed" or stretched out high frequency modulations the farther they are from the spindle.
And so alignment is also less critical, and mistracking distortion is also.
The bottom line is to stop worrying about those "two point" protractors - they'll make you a nutcase.
Records are cut with a linear cutting assembly - and a linear tracking tonearm will play them the same accurate way - pivoted arms cannot do this, and the solution is to worry about my above suggestions about the fussy inner track.
What really matters is the end-of-last-track alignment.
THAT, particularly with an elliptical stylus, must be a perfect angle - stylus cantilever 90 degrees to the spindle - as a typical linear tracking arm would be.
Because at that point of a record, the high frequency modulations are the tightest.
So to best avoid sibilence and distortion of that "last song", this is important.
What's never mentioned is the actual way records are cut, modulation-wise.
The other, outer bands of a record have increasingly "relaxed" or stretched out high frequency modulations the farther they are from the spindle.
And so alignment is also less critical, and mistracking distortion is also.
The bottom line is to stop worrying about those "two point" protractors - they'll make you a nutcase.
Records are cut with a linear cutting assembly - and a linear tracking tonearm will play them the same accurate way - pivoted arms cannot do this, and the solution is to worry about my above suggestions about the fussy inner track.
A passive linear tracking tonearm is not free from tracking error.
A passive linear tracking arm is driven laterally by the sideways force from an angularly displaced cantilever, the same as a pivoting tonearm. However the force required to move a linear tracking tonearm sideways is typically greater than that of a pivoting tonearm.
This results in greater displacement of the cantilever for the linear tracking tonearm. Any displacement of the cantilever introduces tracking error.
Bang & Olufsen once made servo controlled linear tracking tonearms yet they also derived the error signal for the servo from cantilever angular displacement AKA tracking error, as have some Japanese servo controlled linear tracking turntables I have serviced.
A passive linear tracking arm is driven laterally by the sideways force from an angularly displaced cantilever, the same as a pivoting tonearm. However the force required to move a linear tracking tonearm sideways is typically greater than that of a pivoting tonearm.
This results in greater displacement of the cantilever for the linear tracking tonearm. Any displacement of the cantilever introduces tracking error.
Bang & Olufsen once made servo controlled linear tracking tonearms yet they also derived the error signal for the servo from cantilever angular displacement AKA tracking error, as have some Japanese servo controlled linear tracking turntables I have serviced.
My linear tracking Kenwood with optical/servo design is rated for less than 0.2 degrees of any tracking error.
That's nothing worth even worrying about, and surely heaps less than any pivoted arm.
A properly adjusted optical servo linear tracking tonearm may well achieve a tonearm error from tangential alignment approaching as small as 0.2 degrees, but the angle of the tonearm is not the angle of the cantilever or more importantly the stylus, which is the critical angle for tracking error.
To apply some simple trigonometry, let's say the effective tonearm length is 180mm long and the effective cartridge cantilever length is 6mm long. If the angle of the tonearm is in error by 0.2°, then the physical lateral displacement of the headshell at the location of the stylus is:
(tan0.2°)x180 = 0.63mm
This is how far from the optimal location over the track the cartridge is before the servo will start to correct the position of the tonearm and hence begin to move the headshell back to optimal position.
If the cartridge is laterally away from perpendicularly above the groove, then the cantilever cannot be tangential to the groove. The angle of error at the stylus is a function of the cantilever length, namely:
arctan(0.63/6.0) = 6.0°
That's similar to the gross tracking error for a pivoting tonearm.
A linear tracking arm, whether servo controlled or passive, typically advances in small steps every few revolutions. This means even if the tonearm error is always less than 0.2° the tracking error at the stylus will be oscillating between as much as + & - 6.0° for the entire playing of a record side.
With a linear tracking tonearm it is possible in this example for the tracking angle error to swing from +6° to -6° forty times or so from beginning to end of one side of a record. Hopefully someone will jump in to correct me if I have the math wrong!
By contrast, a pivoting arm cycles through a smaller tracking angle error (~±3°) only once per record side.
Your trigonometry aside, I have to state:
Sorry, but your post borders on rediculous and incorrect results.
I don't know how you can take a 0.2 degree lateral arm error (that's ZERO point Two degree - two TENTHS of A single degree) and then come up with a SIX degree difference at the stylus.
Perhaps you'd like to delve into the actual lateral groove modulations themselves, which would add even more cantilever "offset" to your equasions?
As a experienced long time tech, and highly familier with turntables, as well as servicing them, I find that just nonsense, sorry.
johnmath,
I don't know how did you get 6°. If it is true, I would say the design of this particular linear arm is flawed. In fact, it is almost impossible to have + & - 6° tracking error even for a poorly designed linear arm in reality.
You also mixed with servo-controlled linear arms with passive linear arms. I am not going to talk about servo-controlled linear arms, but I don't see why a passive linear arm will start with a 0.2° tracking error.
There are two reasons to cause tracking errors.
1. Geometry. For a pivot arm, the tracking errors caused by its geometry are built in its design and unavoidable. For a passive linear arm, there are no tracking errors caused by geometry at all.
2. Stylus Drag. For a pivot arm, the tracking errors caused by stylus drag do exist. However, a poorly designed passive linear arm may exhibit serious stylus drag, therefore, large tracking errors. But no matter what happens, it will not be + & - 6°. No way.
I am not going to discuss the pros and cons of pivot arms and linear arms here.
I don't know how did you get 6°. If it is true, I would say the design of this particular linear arm is flawed. In fact, it is almost impossible to have + & - 6° tracking error even for a poorly designed linear arm in reality.
You also mixed with servo-controlled linear arms with passive linear arms. I am not going to talk about servo-controlled linear arms, but I don't see why a passive linear arm will start with a 0.2° tracking error.
There are two reasons to cause tracking errors.
1. Geometry. For a pivot arm, the tracking errors caused by its geometry are built in its design and unavoidable. For a passive linear arm, there are no tracking errors caused by geometry at all.
2. Stylus Drag. For a pivot arm, the tracking errors caused by stylus drag do exist. However, a poorly designed passive linear arm may exhibit serious stylus drag, therefore, large tracking errors. But no matter what happens, it will not be + & - 6°. No way.
I am not going to discuss the pros and cons of pivot arms and linear arms here.
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Next time you set up a tangential arm, watch the cartridge and cantilever from the front as it plays a record. You will clearly see the cantilever wiggle from side to side as the tonearm repositions every second or two.
A cantilever is about 6mm long; that equates to about 10 degrees of angle per millimetre of displacement of the tip from centre to left or right of centre.
Another issue is that the stylus tip is not always correctly mounted at 90° to the cantilever. In a pivoting arm this shows up when the static and dynamic anti-skating forces do not coincide. When setting up a tangential tracking arm, confirming the tip alignment is a mandatory step.
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The 0.2° is from the Kenwood turntable specification cited above and used as an example only. I did not claim that all tangential tonearms will have this level of tracking error.
A passive arm requires lateral force from the stylus / cantilever to move the arm along its track. No matter how good the tracking bearings are there is a degree of stiction that causes the arm to move in jumps. Just watch a passive linear tracking arm while playing a record and you will clearly see the arm move in steps.
This movement implies angular rotation of the tonearm, because the other end of the tonearm is not moving in steps; the only way the stylus end of the arm could move in steps is if the stylus skipped grooves. Of course it doesn't because instead the cantilever pivots laterally and that is what causes the 'magnified' tracking error at the stylus tip.
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Again, your (underlined) comments are rediculous to bother with.
NO, my tonearm and stylus does NOT "wiggle" when tracking - I don't know where you got that goofy idea from.
The ONLY wiggling the stylus does is from modulations of the groove.
Get real here!
And NO, my stylus is an Audio Technica without stylus alignment issues, again, you're grasping at straws.
And nobody that I know (normal people) does a microscopic inspection of their stylus/cantilever orientation in order to mount the cartridge per your nonsensical ideas.
Perhaps you're better off convincing those obsessive nut cases over on the vinylengine site of your weird ideas.
Because at 68 years old and been in the business of audio for decades I certainly don't buy it.
This is why a pivoted arm is superior to a mechanical linear tracker. But you already know that. 🙂
Bottom line is your ears are too old and jaded to recognize the other actually more important tracking issues with a pivoted arm. Not enough attention to sq it seems. Functionality is only half the story. I'm sick and tired of some of you old 'know it all' techs blabbering about how there's too much attention being paid to things that make no difference when you're too deaf to even have an opinion about it.
Ahem...so the two point protractor enables the best case scenario with a standard type pivoted arm, just by nature. johnmath's anecdotal explanation of the linear tracker's error lends insight to this fact. You've got 3 undulations across the record as opposed to 2 with a single null protractor. Ideally, both end in a linear position at 90deg in the last groove as mr. wiseguy points out. Depending on the geometry of the arm/pivot/spindle, this is possible. So practically, the 2 null is actually 3 and the 1 null is 2. So, maintaining/acheiving as many nulls as possible across the record is the ultimate goal. Otherwise, you have a much higher degree of phase distortion and tracking error where that audibly gradual and consistent increase and fall off in performance is not realized. It's as good as it gets with a pivot. If you pay attention to the "tech" here, you can put the cart anywhere on the headshell and turn it to 90deg to that last groove. Now that's nuts. I guess maybe not for those like you who prefer their turntable to perform in the worst way possible. Yea, have fun with that, dark and distant with no extension either way.
2 point protractors have been standard practice forever!!
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Here is a test I did before with Ortofon A90, a medium compliance cartridge on my DIY air-bearing arm. I expanded the center hole of a test LP about 2-3 mm and placed the test LP off-center to create eccentricity in order to amplify stylus drag. Please tell me what you see.
Ortofon A90 with heavy air bearing eccentric record test - YouTube
I made three air-bearing arms.
Benz LPS cartridge with medium weight air bearing arm eccentric record test - YouTube
Koetsu rosewood signature cartridge with heavy air bearing arm eccentric record test - YouTube
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Anyone can point and shoot with a camera and get a photograph. But to get a great photograph you need the to take into account the film speed, the iris aperture, the lens focal length, the shutter speed, compensation for backlight or fore-light, the focus, the framing, etc. The picture isn't as good as it can been until all of these are variables are considered.
I consider setting up a turntable to be a bit like getting all the settings optimised for an SLR film camera. When every parameter of a turntable is set up correctly, the sound snaps into almost three dimensional focus in an analogous way IMHO. Of course a plastic turntable isn't going to distinguish this level of detailed setup.
I live remotely off-grid on an island and yet customers from word of mouth drive here on the rather expensive ferry to deliver their turntable for me to set up. I guess I must be doing something right.
I consider setting up a turntable to be a bit like getting all the settings optimised for an SLR film camera. When every parameter of a turntable is set up correctly, the sound snaps into almost three dimensional focus in an analogous way IMHO. Of course a plastic turntable isn't going to distinguish this level of detailed setup.
I live remotely off-grid on an island and yet customers from word of mouth drive here on the rather expensive ferry to deliver their turntable for me to set up. I guess I must be doing something right.
Right. Although it looks like the arm is compensating well, I still see the deflection of the cantilever from the eccentricity. Much more so in the first but I do see it in the others as well. So it would be much more apparent seeing it live. Or with higher mag. Not as much as johnmath pointed out maybe but plenty enough to be audible. it would be far more pronounced on the Kenwood.
The cartridge movement in the frame makes it somewhat difficult to observe, but in all three videos I clearly see the cantilever moving from side to side relative to the cartridge body in the opposite direction to the eccentricity of the record. The Benz is really obvious.
If you can't see it, try this: play your videos frame by frame and note where the cantilever is relative to the cartridge body in each frame. As the frames flick through you will clearly see the cantilever move side to side relative to the cartridge body. If your camera was mounted on the cartridge body (or if you did a frame by frame location adjustment to make the cartridge body appear motionless) it would be blindingly obvious.
The movement is not necessarily very much, but remember for a cantilever of 6mm length between the tip and the suspension, 1mm of lateral movement results in ~10 degrees of tip rotation. At a guess your three cantilever's seem to be moving as much as ~0.2 to 0.5mm peak to peak, or close enough to ±1 - ±2.5° tracking angle variation per revolution IMHO.