Were you talking to John Iverson through your Interociter? That was the BS line he gave me.
The areguements on the way a stylus tracks a groove in the article seems to be based on a marketing description of how a line contact stylus works. Fortunately they don't work that way. Even with a line contact stylus the HF modulations are smaller than the surface radius. And it isn't a line but several small radii at the contact points. The arc of the stylus motion is different from that of the cutterhead, but in both cases the errors from that are very small. the Dynagroove compensation was an adjustable HF boost as the stylus got closer to the center, implemented with a pot tied to the cutterhead. However it was one of the best marketing terms in history.
It is true that to cut a disk that can be played several adjustments to the audio must be made. First the low frequencies must be summed (death to the bass if there was much difference between channels), then dynamics are modulated to keep the cutter from leaving the surface of the disk, but that happens in all mastering because the levels are not always right in the recordings and the dynamic range may be too great for satisfactory playback in anything less than an anechoic chamber.
Vinyl works far better than it should and many people are delighted with the results. Possibly because it requires an effort, which reinforces real respect for the content, something lacking when the music is free, pervasive and no longer an effort to consume.
It is true that to cut a disk that can be played several adjustments to the audio must be made. First the low frequencies must be summed (death to the bass if there was much difference between channels), then dynamics are modulated to keep the cutter from leaving the surface of the disk, but that happens in all mastering because the levels are not always right in the recordings and the dynamic range may be too great for satisfactory playback in anything less than an anechoic chamber.
Vinyl works far better than it should and many people are delighted with the results. Possibly because it requires an effort, which reinforces real respect for the content, something lacking when the music is free, pervasive and no longer an effort to consume.
Thats what i want to say all the times to you all.
ONLY SPHERIC tips work well with Cantilever based cartridges! All other shapes make no sense, just a different sound due different distorsions and resonances.
Mr. Andreoli ( the maker of my Silver Spirit) shows clearly WHY this is true.
Because grooves cutted are tangential and cantilevers work NOT tangential.
Someone should really translate this article in english. No need to be an engineer to understand it.
Joachim can read it in german and explain.
It had to read it many times to fully understand.
In short, he explains, why spheric is better than ANYTHING else on CANTILEVER based Cartridges. And that the damping rubber makes the biggest sound difference at MCs. And that a proper mounting and alignment is important. And that the cantilever has no defined absolute position, this say, short cantilevers give higher output and higher distorsions, long ones vice versa. But long add mass and so on...
And of course, no record can sound better than the mastertape it was made from. No matter which styli, magnet , moon dust or spacemade parts are used for the record player.
Please excuse my bad english
My pulisher/editor heart thinks: someone should translate this...
Then again, it would burst so many dreams and believes here, it might be too cruel to contemplate...
jan didden
Very thoughtfull. I remember when I first met Joachim, he told me that "vinyl replay is a man's thing", what with the carefull adjustments, the act of carefully taking the record from the sleeve, positioning the arm etc. I believe these are factors that add to the enjoyment of vinyl replay. Since then, I bought a turntable and some records, first time in 30 years. I love it!
jan didden
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janneman said:
Come on, you know better than that.
janneman said:
You love it!??? But, Jan, what about those lousy measurements? I'm not sure what you're getting at. Are you saying you love it because it's a man's thing, or because you think the format has some redeeming qualities?
I'm sure those factors do add to enjoyment of vinyl replay for some. Same holds true for those people who get pleasure by listening to equipment with great measurements. But, it's not the whole story.
For myself, I think vinyl is a royal pain in behind!!! I probably can't set up a cart half decent. But I listen to it cause when I put on some well recorded records by say Jimmy Hendrix, or Natalie Merchant's Tiger Lilly I feel like they are in the room. Sounds much more flesh and blood, than the CD counterparts. I don't know why vinyl sounds better, but there is an ease and musicality to the music on well recorded vinyl. It sounds more natural and less fatiguing to my ears, than a well recorded CD. Some recordings I have on LP don't sound as good as the CD version, though that's usually not the case.
John
Making the imposible posible. That is also very human. Playing a record has style i think and i said to Jan it´s an mans thing because it requires dedication and playing around with it. Most women are more pragmatic i think but there is also Martina. The feeling to listen to records is very different too. Ones a month my wife asks me if i can play her some old records from her Hippy time. It makes her very happy as far as i can tell. No digital reproduction comes even close emotionally. It is the quality of the emotion and not the quantity of technical data where the difference is. Digital is in many way better then Vinyl technically. I have no problem with that.
The eliptical stylus was developed in the 1960s in recognition of the fact that for a pivoted tone arm, a spherical stylus would not maintain contact with the same points on the disc as the radial arm cutter and that a spherical stylus in a pivoted arm would result in "pinch distortion" especially evident at the inner grooves. Careful design of the geometry of the arm including optimal overhang for its length, mounting location with respect to the center, and optimal offset angle of the headshell was used to further reduce this pinch effect.
Anti-skating was also added in the 1960s in recognition that the spiraling of the stylus inward would result in uneven distribution of force between the inner and outer wall of the groove. This was made even more imperative because the reduced area of contact eleptical styli offered increased the stress on the vinyl. At high modulaton especially at high frequencies the forces on the stylus were great enough to cause mistracking unless additional vertical force was applied. Anti-skating is a lateral outward force applied to the tonearm to compensate for this effect and equalize the inner and outer wall force on the groove, the goal not to exceed the modulus of elasticity of the soft vinyl and accelerate record wear. The amount of anti skating force has to be adjusted taking into account the amount of vertical tracking force.
Two other trends emerged in the 70s. the multi geometric tetrahedral or Shibata type styus was designed to increase the contact area reducing stress. This was especially necessary for playing CD 4 discs because the rear channels were encoded in frequency upshift bands between 20 khz and 40khz. When these discs are played with styli with relatively high stress levels, these parts of the groove are easily and quickly shaved away. The other trend was the micro-ridge geometry which seemed to carry the eliptical concept in the opposite direction.
The best cartridges have low dynamic mass, high compliance, and well damped mechanical resonances. This reduces tracking force required to track the disc without distortion and without the stylus being kicked off the groove surface only to come crashing down on it to a minimum when paired with a tonearm having suitably matched resonant properties, a resonance frequency low enough to be below the audible range, high enough to be above the record warp frequency, and well damped. A resonant frequency in the 9 to 11 hz range is probably optimal for the cartridge/arm combination.
For this reason, the moving magnet design is superior to the moving coil design. Both work on exactly the same principle. The only difference is whether the field coil moves and the fixed magnets remain stationary or the magnet moves and the coil remains stationary. Because very powerful magnets can be made very small and machined with great precision, more coil turns and therefore higher output can be achieved with with a moving magnet. As more turns are wound on the coil, its mass becomes heavier. Geometric alignment of the coils to the same degree of precision can also be a problem resulting in greater unit to unit variation in manufacture.
Higher output, lower dynamic mass, and easily designed user replacable styli put the MM design in the forefront.
The piezo-electric effect has been known for a very long time. phonograph cartridges based on this principle have many inherent advantages. Much higher output is one, immunity to hum and noise is another. This design was never developed to a significant degree for high performance record playback. This must have been the result of inherent problems I'm not aware of. However, their advantages made them the universal choice for mass produced phonographs from the least expensive to consoles costing up to several hundred dollars. Most prominent among the manufacturers were Sonotone, Astatic, and Ronnette.
Anti-skating was also added in the 1960s in recognition that the spiraling of the stylus inward would result in uneven distribution of force between the inner and outer wall of the groove. This was made even more imperative because the reduced area of contact eleptical styli offered increased the stress on the vinyl. At high modulaton especially at high frequencies the forces on the stylus were great enough to cause mistracking unless additional vertical force was applied. Anti-skating is a lateral outward force applied to the tonearm to compensate for this effect and equalize the inner and outer wall force on the groove, the goal not to exceed the modulus of elasticity of the soft vinyl and accelerate record wear. The amount of anti skating force has to be adjusted taking into account the amount of vertical tracking force.
Two other trends emerged in the 70s. the multi geometric tetrahedral or Shibata type styus was designed to increase the contact area reducing stress. This was especially necessary for playing CD 4 discs because the rear channels were encoded in frequency upshift bands between 20 khz and 40khz. When these discs are played with styli with relatively high stress levels, these parts of the groove are easily and quickly shaved away. The other trend was the micro-ridge geometry which seemed to carry the eliptical concept in the opposite direction.
The best cartridges have low dynamic mass, high compliance, and well damped mechanical resonances. This reduces tracking force required to track the disc without distortion and without the stylus being kicked off the groove surface only to come crashing down on it to a minimum when paired with a tonearm having suitably matched resonant properties, a resonance frequency low enough to be below the audible range, high enough to be above the record warp frequency, and well damped. A resonant frequency in the 9 to 11 hz range is probably optimal for the cartridge/arm combination.
For this reason, the moving magnet design is superior to the moving coil design. Both work on exactly the same principle. The only difference is whether the field coil moves and the fixed magnets remain stationary or the magnet moves and the coil remains stationary. Because very powerful magnets can be made very small and machined with great precision, more coil turns and therefore higher output can be achieved with with a moving magnet. As more turns are wound on the coil, its mass becomes heavier. Geometric alignment of the coils to the same degree of precision can also be a problem resulting in greater unit to unit variation in manufacture.
Higher output, lower dynamic mass, and easily designed user replacable styli put the MM design in the forefront.
The piezo-electric effect has been known for a very long time. phonograph cartridges based on this principle have many inherent advantages. Much higher output is one, immunity to hum and noise is another. This design was never developed to a significant degree for high performance record playback. This must have been the result of inherent problems I'm not aware of. However, their advantages made them the universal choice for mass produced phonographs from the least expensive to consoles costing up to several hundred dollars. Most prominent among the manufacturers were Sonotone, Astatic, and Ronnette.
Hi everybody, your questions about the 'strain-gage' phono cartridge are answered in the latest, that is March 2011 issue of 'Stereophile' The article is: 'Soundsmith SG-200 strain-gauge phono cartridge system'. Unfortunately, no measurements were made, but it is still an interesting read.
They are very high impedance and prone to pick up stray E field, I figure the relativley huge output swamps the hum.
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Hi Soundminded,
Thanks for this overview. I'm certainly not an expert on cartridge-tonearm issues, but what you say about MM vs MC cartridges is certainly an eye-opener and likely a subject of controversy. It will be interesting to see how others here chime in on this.
You also mention some familiar terms from long ago, like anti-skating. When we look at some of the very expensive turntable/arm combinations out there today, do they implement these things, or go even further and implement ever newer, more sophisticated innovations?
Cheers,
Bob
Cutter Stylus Geometry vs Playback Stylus Geometry
I have spent a little time examining cutting lathes, and the axial orientation and cutting action of the voice coil motors is radial to the center of the disc, and at + or - 45° to the plane of the disc. However, the considerable tangental reaction force to the rotation of the lacquer or copper being cut is borne by a cantilever at the back of the cutting stylus. This would seem to me to be translating the cutting action from a purely radial motion to a spherical section motion just as in a playback stylus/cantilever system.
The length of the cutter cantilever would determine the radius of the spherical section being circumscribed, just as is the case with a playback stylus. The difference in cantilever length between the cutter and playback head would determine the amount of differential tangental modulation due to groove amplitude (there is no tangential error with zero modulation). Does this paper we are referencing here delineate this effect? It would seem (oddly enough) to be a time-domain distortion dependent on amplitude, since a tangential error is forward or backward in time as the disc rotates (yet another source of FM?).
As far as spherical stylui being optimum, considering the diameter of a stylus as it enters the groove, a purely spherical cross-section stylus will have a contact patch too long in the tangental axis to allow for accurate tracing of high frequencies, this is the reason that there is back-clearance ground into the cutting stylus profile. If the spherical radius is reduced to allow for accurate high frequency tracing, the stylus will ride to low in the groove and interact with debris.
I thought (probably in ignorance) that was the reason for taking small radius contact patches and moving them farther apart on an ellipse with it's major axis oriented radially? It sould seem to have the advantages of a small-radius spherical contact patch with the proper positioning on the side-wall of the groove. I guess the devil is in the details, but couldn't the shape of the ellipse be just so as to approximate a sphere at the point of contact?
I wish an expert in stylus design and grinding could chime in here, not just the hypothesizing of users like myself.
Howard Hoyt
CE - WXYC-FM 89.3
Chapel Hill, NC
www.wxyc.org
1st on the Internet
I have spent a little time examining cutting lathes, and the axial orientation and cutting action of the voice coil motors is radial to the center of the disc, and at + or - 45° to the plane of the disc. However, the considerable tangental reaction force to the rotation of the lacquer or copper being cut is borne by a cantilever at the back of the cutting stylus. This would seem to me to be translating the cutting action from a purely radial motion to a spherical section motion just as in a playback stylus/cantilever system.
The length of the cutter cantilever would determine the radius of the spherical section being circumscribed, just as is the case with a playback stylus. The difference in cantilever length between the cutter and playback head would determine the amount of differential tangental modulation due to groove amplitude (there is no tangential error with zero modulation). Does this paper we are referencing here delineate this effect? It would seem (oddly enough) to be a time-domain distortion dependent on amplitude, since a tangential error is forward or backward in time as the disc rotates (yet another source of FM?).
As far as spherical stylui being optimum, considering the diameter of a stylus as it enters the groove, a purely spherical cross-section stylus will have a contact patch too long in the tangental axis to allow for accurate tracing of high frequencies, this is the reason that there is back-clearance ground into the cutting stylus profile. If the spherical radius is reduced to allow for accurate high frequency tracing, the stylus will ride to low in the groove and interact with debris.
I thought (probably in ignorance) that was the reason for taking small radius contact patches and moving them farther apart on an ellipse with it's major axis oriented radially? It sould seem to have the advantages of a small-radius spherical contact patch with the proper positioning on the side-wall of the groove. I guess the devil is in the details, but couldn't the shape of the ellipse be just so as to approximate a sphere at the point of contact?
I wish an expert in stylus design and grinding could chime in here, not just the hypothesizing of users like myself.
Howard Hoyt
CE - WXYC-FM 89.3
Chapel Hill, NC
www.wxyc.org
1st on the Internet
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I wish there were measurements. We may be criticizing too soon, since the strain guage is resistive there could be some SMT R's and C's in there to fix the response. In my experience the resistance of the elements was very tightly controlled.
Huge thread here covering patents, etc. Turntable Forum :: View topic - Advanced Stylus Shapes: Pics, discussion, patents.
Attachments
Thats WRONG!!!
The cutter works radial. Yes
The stylus tip on cantilever never, because it is similar to a pivoted tonarm.
As the groove is modulated, the cantilever move up/down and left/right to generate signal.
Normal pivoted arms also change the tracking angle,due this circlelike movement while (perfect) radial arms do not. Can be reduced by overhang and offset angle.
Cantilevers have the same problem, but no offset and no overhang!
The cantilever movement on the circle create a phase distorsion, it does not matter, if it will be it a spheric or elliptic or hyperbolic stylus.
BUT : Any non spheric tip will change his radius when turned sideward or up/down, !
Thus the contact surface changes dependent of modulations and you have no real tracking control, this is like a moving target.
If you go for bowling, you will use a round ball, not an elliptic one! Why?
Stylus Info
Thanks Scott, that was an excellent find...now to try and parse some facts out of yet another forum...need more hours in the day. I wish there was a browser plug-in which improved the signal to noise of a forum...hey, we need Dolby IP!!!
Howard Hoyt
CE - WXYC-FM 89.3
Chapel Hill, NC
www.wxyc.org
1st on the Internet
Thanks Scott, that was an excellent find...now to try and parse some facts out of yet another forum...need more hours in the day. I wish there was a browser plug-in which improved the signal to noise of a forum...hey, we need Dolby IP!!!
Howard Hoyt
CE - WXYC-FM 89.3
Chapel Hill, NC
www.wxyc.org
1st on the Internet
As long as we're talking about small signals (and that's where preamplification gets interesting), Scott likes to say, "The Hall Effect is a Small Effect." But too small to be used for phono transduction?
One advantage I can see from displacement methods is the ability to look at DC. This could be incredibly useful for setup of tracking force and antiskate.
One advantage I can see from displacement methods is the ability to look at DC. This could be incredibly useful for setup of tracking force and antiskate.
This paper of Mr. Andreoli give answer for all those things.
In the first part you describe what a cutter does and that the cutterstylus is somewhat angled.
Yes, thats why cantilevers are not mounted paralled to the record surface and why VTA setting is important.
At the inner end every record is not as good as outside.
You write that spheric styli should change diameter at the inner side. So it will be the same problem for elliptical ones.
Ellipitical is perfect for non modulated grooves. Yes.
As there is modulation, they create more errors than they try to compensate.
""The eliptical stylus was developed in the 1960s in recognition of the fact that for a pivoted tone arm, a spherical stylus would not maintain contact with the same points on the disc as the radial arm cutter""
I agree.
As long as the spherical stylus is normal to the plane of the disk, it will contact the same lines.
Why is a pure conical geometry called a sphere?
As an aside, has anybody ever tried to modulated the antiskate force based on signal amplitude?
Cheers, John
I agree.
As long as the spherical stylus is normal to the plane of the disk, it will contact the same lines.
Why is a pure conical geometry called a sphere?
As an aside, has anybody ever tried to modulated the antiskate force based on signal amplitude?
Cheers, John
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