Hi Nandric,
in researching cartridge and cantilever behaviour there are a range of distortions that are directly related to cantilever behaviour...
Specifically: cantilever resonance, and torsion/flexing.
The first I am starting to get a reasonable handle on ( and appears to be mostly unknown/ignored/disregarded by most audiophiles)... the cantilever resonance can influence both frequency and phase response octaves above and below the peak resonance point...
Numerous designers have used the cantilever resonance along with the electrical resonance to generate a near flat frequency response but there are problems with this approach.. the idea of combining a series of flaws to end up with a result close to the target is..... problematic!
The Shure M series are examples, so are most of the empires, and the Audio Technica aluminium cantilever cartridges.
The things that define the frequency of the resonance are the proportions and shape of the cantilever, along with the rigidity and speed of sound (closely related!) through the material.
Harder materials tend to have faster speed of sound and higher resonant frequencies (also achieved with shorter cantilevers...) - so there are advantages to certain shapes (tubes, tapering) - but many advantages come with materials - diamond, ruby/sapphire, boron and beryllium are all examples.
In the search for improved linearity, one approach it to move all resonances up and out of the Audio range - cantilever materials are key to this.
Another aspect of this, is that apparently torsion/flex in a cantilever (which happens more with the less rigid materials.... like aluminium) tend to lead to various forms of distortion - including the Euphonic second harmonic.
Here we start to divide into the usual subjectivist vs objectivist camps, and the reproducer-archivist vs musician/stereo-as-musical-instrument camps.
I fall relatively firmly into the objectivist and reproducer-archivist camps. So my goal is to reproduce the original master recording as best I can....
Thereafter if I want to add euphonic distortion to it (and distortion is by definition anything that was not in, or differentiates from, the original master!) I can use equalisation and other forms of sound tailoring to achieve it.
Excellent cartridges like the AT440MLa have cantilever resonances impacting on the sound at frequencies of around 10kHz - the tapered aluminium cantilever and its damping have been designed to control the resonance to best effect - but these styli do not achieve the level of quality that the ATN150MLX stylus does - substantially because of its boron cantilever (it has of course the same proportions, but the damping is varied somewhat) - so the MLx has its resonance peak above 20kHz (not far above though) and although it does impact on the audible range down to perhaps 15kHz, the impact is slight... and the cartridge sounds substantially the better for it.
Also knowing the material does not tell us about the shape/structure of the material.
Technics made boron tubes using a vapor deposition method, probably similar to the methods used by Shure and AT for their Beryllium tube cantilevers... the Technics literature of the time claimed that for a cantilever of the same shape and proportions, their Boron tube was superior to ruby/sapphire or diamond cantilevers. (in terms of raising the resonance to a higher frequency and increasing torsional rigidity)
So speaking theoretically the "exotic" materials have the edge....
Speaking practically in the real world - implementation is everything! - Digital implemented right is superior in every way to vinyl analogue as a recording and reproduction medium... but there are so very many digital systems that sound terrible!
And so many analogue systems that rise above their imperfections to sound great.
I admit to being on a search for a holy grail.... or at least a small collection of cartridges that I will settle down with for a number of years....
I do love the sound of the Aluminium cantilevered ADC SuperXLM shibata, and the beryllium cantilever AT20ss.
But I am still seeking cartridges that move the resonance totally out of the 20-20 range - and I have not found one yet. (maybe when I find it, I will discover it makes no difference, and the grass was always greener on this side of the fence...)
To summaries my (as usual) verbose posting.... the desirable qualities in a cantilever include torsional rigidity and higher resonance frequency, as a result aluminium is a less desirable material - in shorthand terms you can rank cantilevers by material Aluminium being the lowest rank, then Titanium (and perhaps carbon fibre?), and then the exotic materials.
Also cantilevers can be ranked by solid (lower) and hollow (higher) as well as straight (lower) and tapered (higher).
It does give us a handy way of looking at a cartridges specifications "sound unheard" and make some sort of judgement as to where it might rank in the cartridge sound quality continuum.
Essential given that many of us have no hope of hearing any of these cartridges without purchasing them.
So some of my criteria (flawed as they may be) in my search for the Holy Cartridge....
1) A cantilever that has a decent chance of placing the resonance around an octave beyond the audible range or higher
2) Low inductance (so as to also remove the electrical resonance)
3) a Body either designed for good damping or that can easily be modded/adjusted to improve its damping.
4) High tracking capability
5) Flat frequency response
And I prefer removeable styli - if additional rigidity is required in the stylus mounting, it can be achieved with a tiny amount of plasticine or blue-tack. - I do like those cartridges that screw the stylus mounting in (Technics 100/205 and TK9/10) for max rigidity while maintaining exchangeability.
Raul - my comments with regards to the AT13/14/15/20 and the TK1/3/5/7 - was related to the construction of their rather heavier metal bodies, as opposed to the closely related AT10/11/12 cartridges
AT was clearly doing something similar to what CA have done with their cartridges.
The differing stylus mounts also impact on the stylus/body vibration environment, with the signets having the better design for vibration control. - Which is not to say that a particular exemplar might not have a problem.... as I mentioned earlier, experiments with one or two thin threads of plasticine or blue-tack may make a substantial difference to some cartridges...
Best fitted between two rigid surfaces and in a very thin layer to maximise shear effec which is a valuable damper... between stylus and body is just about perfect. A tiny amount between cartridge and headshell may also help in some cases (more experimentation needed here...)
bye for now
David
in researching cartridge and cantilever behaviour there are a range of distortions that are directly related to cantilever behaviour...
Specifically: cantilever resonance, and torsion/flexing.
The first I am starting to get a reasonable handle on ( and appears to be mostly unknown/ignored/disregarded by most audiophiles)... the cantilever resonance can influence both frequency and phase response octaves above and below the peak resonance point...
Numerous designers have used the cantilever resonance along with the electrical resonance to generate a near flat frequency response but there are problems with this approach.. the idea of combining a series of flaws to end up with a result close to the target is..... problematic!
The Shure M series are examples, so are most of the empires, and the Audio Technica aluminium cantilever cartridges.
The things that define the frequency of the resonance are the proportions and shape of the cantilever, along with the rigidity and speed of sound (closely related!) through the material.
Harder materials tend to have faster speed of sound and higher resonant frequencies (also achieved with shorter cantilevers...) - so there are advantages to certain shapes (tubes, tapering) - but many advantages come with materials - diamond, ruby/sapphire, boron and beryllium are all examples.
In the search for improved linearity, one approach it to move all resonances up and out of the Audio range - cantilever materials are key to this.
Another aspect of this, is that apparently torsion/flex in a cantilever (which happens more with the less rigid materials.... like aluminium) tend to lead to various forms of distortion - including the Euphonic second harmonic.
Here we start to divide into the usual subjectivist vs objectivist camps, and the reproducer-archivist vs musician/stereo-as-musical-instrument camps.
I fall relatively firmly into the objectivist and reproducer-archivist camps. So my goal is to reproduce the original master recording as best I can....
Thereafter if I want to add euphonic distortion to it (and distortion is by definition anything that was not in, or differentiates from, the original master!) I can use equalisation and other forms of sound tailoring to achieve it.
Excellent cartridges like the AT440MLa have cantilever resonances impacting on the sound at frequencies of around 10kHz - the tapered aluminium cantilever and its damping have been designed to control the resonance to best effect - but these styli do not achieve the level of quality that the ATN150MLX stylus does - substantially because of its boron cantilever (it has of course the same proportions, but the damping is varied somewhat) - so the MLx has its resonance peak above 20kHz (not far above though) and although it does impact on the audible range down to perhaps 15kHz, the impact is slight... and the cartridge sounds substantially the better for it.
Also knowing the material does not tell us about the shape/structure of the material.
Technics made boron tubes using a vapor deposition method, probably similar to the methods used by Shure and AT for their Beryllium tube cantilevers... the Technics literature of the time claimed that for a cantilever of the same shape and proportions, their Boron tube was superior to ruby/sapphire or diamond cantilevers. (in terms of raising the resonance to a higher frequency and increasing torsional rigidity)
So speaking theoretically the "exotic" materials have the edge....
Speaking practically in the real world - implementation is everything! - Digital implemented right is superior in every way to vinyl analogue as a recording and reproduction medium... but there are so very many digital systems that sound terrible!
And so many analogue systems that rise above their imperfections to sound great.
I admit to being on a search for a holy grail.... or at least a small collection of cartridges that I will settle down with for a number of years....
I do love the sound of the Aluminium cantilevered ADC SuperXLM shibata, and the beryllium cantilever AT20ss.
But I am still seeking cartridges that move the resonance totally out of the 20-20 range - and I have not found one yet. (maybe when I find it, I will discover it makes no difference, and the grass was always greener on this side of the fence...)
To summaries my (as usual) verbose posting.... the desirable qualities in a cantilever include torsional rigidity and higher resonance frequency, as a result aluminium is a less desirable material - in shorthand terms you can rank cantilevers by material Aluminium being the lowest rank, then Titanium (and perhaps carbon fibre?), and then the exotic materials.
Also cantilevers can be ranked by solid (lower) and hollow (higher) as well as straight (lower) and tapered (higher).
It does give us a handy way of looking at a cartridges specifications "sound unheard" and make some sort of judgement as to where it might rank in the cartridge sound quality continuum.
Essential given that many of us have no hope of hearing any of these cartridges without purchasing them.
So some of my criteria (flawed as they may be) in my search for the Holy Cartridge....
1) A cantilever that has a decent chance of placing the resonance around an octave beyond the audible range or higher
2) Low inductance (so as to also remove the electrical resonance)
3) a Body either designed for good damping or that can easily be modded/adjusted to improve its damping.
4) High tracking capability
5) Flat frequency response
And I prefer removeable styli - if additional rigidity is required in the stylus mounting, it can be achieved with a tiny amount of plasticine or blue-tack. - I do like those cartridges that screw the stylus mounting in (Technics 100/205 and TK9/10) for max rigidity while maintaining exchangeability.
Raul - my comments with regards to the AT13/14/15/20 and the TK1/3/5/7 - was related to the construction of their rather heavier metal bodies, as opposed to the closely related AT10/11/12 cartridges
AT was clearly doing something similar to what CA have done with their cartridges.
The differing stylus mounts also impact on the stylus/body vibration environment, with the signets having the better design for vibration control. - Which is not to say that a particular exemplar might not have a problem.... as I mentioned earlier, experiments with one or two thin threads of plasticine or blue-tack may make a substantial difference to some cartridges...
Best fitted between two rigid surfaces and in a very thin layer to maximise shear effec which is a valuable damper... between stylus and body is just about perfect. A tiny amount between cartridge and headshell may also help in some cases (more experimentation needed here...)
bye for now
David