diy morsiani antiskating questions
Greetings all, would someone kindly explain in detail the morisani magnetic antiskating regarding adjusting(I assume its the height of the magnets on the armbord that are adjusted) and what type of magnets. I assume neo's are too strong, any thoughts. Also I intend to use fairly high compliannce carts as I haven't got the dough to go down the mc road. Is this an issue?Also any photos of finished unipivots employing this system would be greatly appreciated. kind regards fergs
Greetings all, would someone kindly explain in detail the morisani magnetic antiskating regarding adjusting(I assume its the height of the magnets on the armbord that are adjusted) and what type of magnets. I assume neo's are too strong, any thoughts. Also I intend to use fairly high compliannce carts as I haven't got the dough to go down the mc road. Is this an issue?Also any photos of finished unipivots employing this system would be greatly appreciated. kind regards fergs
Hi,
A magnetic system may impart a twisting (azimuth) motion into the unipivot and the magnitude of the twisting could change as the arm sweeps across the playing surface.
Careful design to eliminate this effect may be needed.
Slightly off topic:-
I have read an article (& website) that shows a pair of dumbells attatched to the headshell to increase azimuth inertia. It is an ideal way to load a unipivot to help prevent lateral movements and vibrations.
A magnetic system may impart a twisting (azimuth) motion into the unipivot and the magnitude of the twisting could change as the arm sweeps across the playing surface.
Careful design to eliminate this effect may be needed.
Slightly off topic:-
I have read an article (& website) that shows a pair of dumbells attatched to the headshell to increase azimuth inertia. It is an ideal way to load a unipivot to help prevent lateral movements and vibrations.
Morsiani antiskating
Nobody can explain thsi better than Morsiani himself.
If you look in my website www.morsiani.it there are enough pictures and one drawing showing how the 4 alnico magnet are placed.
The antiskating force is adjusted employing an uncutted disc ,then you can employ a test disc with recorded frequencies and a dual trace oscilloscope , but this is not mandatory.
Thre are two magnets in the pivot turret,these can be called rotor ,and two magnets in the armbase,these can be called stator.
The two magnets in the turret are placed horizontally and with opposed polarity,the two magnets in the armbase are placed vertically and the north pole is in the bottom side.
Raising these magnets the force increases , because the distance between the stator and rotor is diminished.
Then the two magnets in the pivot turret are placed in a disc which can be turned, this adjusts the run of the antiskating .
The noth pole of one magnets of the rotor must be aligned with the south pole of the magnet inthe right side of the stator when the stylus is on the first groove.
My magnets dispalcement can demonstrate that the skating force is not constant across the disc,but it diminishes toward the disc centre.
Adjust the two side magnets of the stator at the same height to keep the arm stopped when it is at the middle point of the disc.
Then put the arm at the disc end,and the arm returns at the middle.
This means that from the middle to the end the antiskating force is too much.
Then put the arm at the beginning of the disc,the arm run toward the middle.This means that the antiskating force is scarce.
This can be done with an unipivot arm,because the friction is very low,some cardanic arms with balls race bearings have friction greater than the small difference of the skate force,so this effect can not be detected.
Now you can push up the magnet on the right side of the arm,increasing the force from the beginning to the middle,and pull down the magnet on the left side of the arm,diminishing the antiskating force from the middle to the end.
In this way the arm can be adjusted to stay stopped in the all of the disc surface ,but this is valid for a flat disc,but the cutted disc offers more surface to the stylus,so a gretar force is useful .
I adjust the arm to have a slow motion toward the outer of the disc.
At this point a test disc is useful for fine adjustment to have the best traking in all the disc surface.
The best traking is obtained when the pressure of the stylus is balanced on the two sides of the groove from the beginning to the end of the disc.
This can not be allowed by constant force antiskating ,my method is more accurate .I invented this 10 years ago,and since now it is unequalled ,because this reduces distortion and the vinyl wear,remember that the diamond is harder than vinyl !
Best regards,
Carlo Morsiani
Nobody can explain thsi better than Morsiani himself.
If you look in my website www.morsiani.it there are enough pictures and one drawing showing how the 4 alnico magnet are placed.
The antiskating force is adjusted employing an uncutted disc ,then you can employ a test disc with recorded frequencies and a dual trace oscilloscope , but this is not mandatory.
Thre are two magnets in the pivot turret,these can be called rotor ,and two magnets in the armbase,these can be called stator.
The two magnets in the turret are placed horizontally and with opposed polarity,the two magnets in the armbase are placed vertically and the north pole is in the bottom side.
Raising these magnets the force increases , because the distance between the stator and rotor is diminished.
Then the two magnets in the pivot turret are placed in a disc which can be turned, this adjusts the run of the antiskating .
The noth pole of one magnets of the rotor must be aligned with the south pole of the magnet inthe right side of the stator when the stylus is on the first groove.
My magnets dispalcement can demonstrate that the skating force is not constant across the disc,but it diminishes toward the disc centre.
Adjust the two side magnets of the stator at the same height to keep the arm stopped when it is at the middle point of the disc.
Then put the arm at the disc end,and the arm returns at the middle.
This means that from the middle to the end the antiskating force is too much.
Then put the arm at the beginning of the disc,the arm run toward the middle.This means that the antiskating force is scarce.
This can be done with an unipivot arm,because the friction is very low,some cardanic arms with balls race bearings have friction greater than the small difference of the skate force,so this effect can not be detected.
Now you can push up the magnet on the right side of the arm,increasing the force from the beginning to the middle,and pull down the magnet on the left side of the arm,diminishing the antiskating force from the middle to the end.
In this way the arm can be adjusted to stay stopped in the all of the disc surface ,but this is valid for a flat disc,but the cutted disc offers more surface to the stylus,so a gretar force is useful .
I adjust the arm to have a slow motion toward the outer of the disc.
At this point a test disc is useful for fine adjustment to have the best traking in all the disc surface.
The best traking is obtained when the pressure of the stylus is balanced on the two sides of the groove from the beginning to the end of the disc.
This can not be allowed by constant force antiskating ,my method is more accurate .I invented this 10 years ago,and since now it is unequalled ,because this reduces distortion and the vinyl wear,remember that the diamond is harder than vinyl !
Best regards,
Carlo Morsiani
well I didn;t think i'd be talking to the man himself. your explanation is clear as a bell, thankyou. what would you sugest in the way of magnets for the diy'ers (are neo rods too strong)and also is the spacing of the turret magnets critical..this system is far more appealing than taangentiaal arms in terms of ease of construction. Carlos thankyou for your help, its a brilliant desiign cheers fergs
Hi Fergs 1,
really my arm is easier to make than a tangential arm ,end easier to set-up,and it works without any problem forever ,and it sounds definitey better than tangential arm,cardanic arm,and all unipivots arm without antiskating or with wire and counterweight antiskating .
I published my arm 10 years ago,there are more DIY unit made than the units made and sold by me.
As Mr Constant Verdier wrote , it is a previlege of the best ones to be copied .
In 10 years I had enough work ,so DIY copies are not a problem,instead this is the evidence that
my metod is validated by reproducibility.
You can see that the antiskating is considered an accessory which can be deleted,instead this is very important to have good traking,and keep low the distortion.
Following my method,
You will have stable and focused stereo image,and female voice will stay firm ,and will not fly around like a butterfly .
Then remember that the bearing is the heart of the arm,the pivot matter has its own sonic signature,I choose the harmonic steel,but you can experiment what you like as diamond,sapphire,tungsten,wolframium,stell of various hardness..
Best regards,Carlo Morsiani
really my arm is easier to make than a tangential arm ,end easier to set-up,and it works without any problem forever ,and it sounds definitey better than tangential arm,cardanic arm,and all unipivots arm without antiskating or with wire and counterweight antiskating .
I published my arm 10 years ago,there are more DIY unit made than the units made and sold by me.
As Mr Constant Verdier wrote , it is a previlege of the best ones to be copied .
In 10 years I had enough work ,so DIY copies are not a problem,instead this is the evidence that
my metod is validated by reproducibility.
You can see that the antiskating is considered an accessory which can be deleted,instead this is very important to have good traking,and keep low the distortion.
Following my method,
You will have stable and focused stereo image,and female voice will stay firm ,and will not fly around like a butterfly .
Then remember that the bearing is the heart of the arm,the pivot matter has its own sonic signature,I choose the harmonic steel,but you can experiment what you like as diamond,sapphire,tungsten,wolframium,stell of various hardness..
Best regards,Carlo Morsiani
A big thanks from me also for your explanation
A few more readings and I maybe can figure it out, I think I have to build it and see it in action to fully understand it. I have difficult understanding mechanical ideas without seeing/touching it.
Will a diameter of 5 mm work for the alnico magnets?
A few more readings and I maybe can figure it out, I think I have to build it and see it in action to fully understand it. I have difficult understanding mechanical ideas without seeing/touching it.
Will a diameter of 5 mm work for the alnico magnets?
In attachment two drawings,
in drawing n°6 the arm turret and the magnets displacement are shown ,
in the drawing n°7 the arm is shown from the top side,so you can see the alignment of the magnets at the beginning of the disc.
In action you will see how it works.
The disc with two oppsed magnets on the top side of the turret are kept in centre by a proturusion ,which diameter is of 5 mm,in this there is screwed a screw without head of mm 3,and an M 3 blind nut locks the magnets disc to the turret,losing the blind nut you can adjust the antiskating run.
I never released these drawings on internet before, there is a copyright owned by me,and these drawings can not reproduced or duplicated in other websites than www.diyaudio.com without my permission.
Best regards,Carlo Morsiani.
in drawing n°6 the arm turret and the magnets displacement are shown ,
in the drawing n°7 the arm is shown from the top side,so you can see the alignment of the magnets at the beginning of the disc.
In action you will see how it works.
The disc with two oppsed magnets on the top side of the turret are kept in centre by a proturusion ,which diameter is of 5 mm,in this there is screwed a screw without head of mm 3,and an M 3 blind nut locks the magnets disc to the turret,losing the blind nut you can adjust the antiskating run.
I never released these drawings on internet before, there is a copyright owned by me,and these drawings can not reproduced or duplicated in other websites than www.diyaudio.com without my permission.
Best regards,Carlo Morsiani.
Attachments
drawings
I see that there is only one drawing in my previous reply,in this I post the missing one.
The ALNICO magnets are these:
n° 2 diameter mm 6,lenght mm 20 for the arm turret(rotor)
n° 2 diameter mm10,lenght mm 30,for the arm base (stator).
Answering to FERGS 1 question,the idea came from the DECCA international arm,it ws the only one with unipivot bearing and magnetic antiskating.But the magnets do not allow to be adjusted separately,because are tied toghether.
I did not invented the unipivot arm with magnetic antiskating , I invented a new magnets displacement and the method of adjusting the antiskating force.
The cutted groove has two sides, it is very important that the pressure of the stylus is balanced on these two sides.
In my previous mail I described how it is possible to demonstrate that the skating force is diminishing toward the centre of the disc.
So it is useful to adjust the antiskating accordingly.
If this does not happens,mistraking occurs,and this means distortion.My method allows to keep balanced the stlus pressure on the two sides of the groove from the beginning to the end of the disc,
giving less distortion,more stable and focused stereo image.
The mono discs play in the middle of the speakers, and the sound does not floats from one speaker to the other.
Then with my design,the mono cartridge for mono discs is not necessary,if you have a stereo system.
So You do not need to depress that damned "mono "button,which parallels the two channels,and causes high frquencies losses and worser sound.
Best regards,Carlo Morsiani.
I see that there is only one drawing in my previous reply,in this I post the missing one.
The ALNICO magnets are these:
n° 2 diameter mm 6,lenght mm 20 for the arm turret(rotor)
n° 2 diameter mm10,lenght mm 30,for the arm base (stator).
Answering to FERGS 1 question,the idea came from the DECCA international arm,it ws the only one with unipivot bearing and magnetic antiskating.But the magnets do not allow to be adjusted separately,because are tied toghether.
I did not invented the unipivot arm with magnetic antiskating , I invented a new magnets displacement and the method of adjusting the antiskating force.
The cutted groove has two sides, it is very important that the pressure of the stylus is balanced on these two sides.
In my previous mail I described how it is possible to demonstrate that the skating force is diminishing toward the centre of the disc.
So it is useful to adjust the antiskating accordingly.
If this does not happens,mistraking occurs,and this means distortion.My method allows to keep balanced the stlus pressure on the two sides of the groove from the beginning to the end of the disc,
giving less distortion,more stable and focused stereo image.
The mono discs play in the middle of the speakers, and the sound does not floats from one speaker to the other.
Then with my design,the mono cartridge for mono discs is not necessary,if you have a stereo system.
So You do not need to depress that damned "mono "button,which parallels the two channels,and causes high frquencies losses and worser sound.
Best regards,Carlo Morsiani.
Attachments
Dear Mr. Morsiani,
Great to see you participating in this forum. Just for your information, there was at least one more unipivot arm that featured magnetic skating force compensation: The KMAL(Keith Monks Audio Labs) arm, mostly remembered for the use of Mercury as a conductive element(in the true sense of the word between armwand wiring and tonearm base wiring. In this design, the skating compensation is higher at the outer edge of the record too, but it is preset for a VTF of ~ 1,5gr.
Greetings from Berlin,
Frank Schröder
Great to see you participating in this forum. Just for your information, there was at least one more unipivot arm that featured magnetic skating force compensation: The KMAL(Keith Monks Audio Labs) arm, mostly remembered for the use of Mercury as a conductive element(in the true sense of the word
between armwand wiring and tonearm base wiring. In this design, the skating compensation is higher at the outer edge of the record too, but it is preset for a VTF of ~ 1,5gr.Greetings from Berlin,
Frank Schröder
Dear Mr Schroder,
you are right.
I remember the Kmal arm .This unusual Kmal arm was dedicated to high compliance cartridges .
I have the original brochure ,wich I collected in Milan hifi show when Kmal products were introduced in Italy in the end of the seventies.
But I never purchased it , and never I had one in my hands,it is a rare item to find.
I remember also the other product of Keith Monks,the vinyl washing machine .
But this arm was not so inspiring for me like the Decca international arm,so I forgot to mention it.
This is a thing of more than 35 years ago.
Over fifty years old audiophiles only can remember this.
Best regards,Carlo Morsiani
you are right.
I remember the Kmal arm .This unusual Kmal arm was dedicated to high compliance cartridges .
I have the original brochure ,wich I collected in Milan hifi show when Kmal products were introduced in Italy in the end of the seventies.
But I never purchased it , and never I had one in my hands,it is a rare item to find.
I remember also the other product of Keith Monks,the vinyl washing machine .
But this arm was not so inspiring for me like the Decca international arm,so I forgot to mention it.
This is a thing of more than 35 years ago.
Over fifty years old audiophiles only can remember this.
Best regards,Carlo Morsiani
Hello Mr. Morsiani,
Seven more years left, sigh.....
But if you'd ever feel the urge to try the KMAL arm, I would gladly send it to you so you could inspect it/play with it for a couple of months. It's been sitting in a drawer for several years anyway. Just let me know off list.
Best,
Frank Schröder
Seven more years left, sigh.....
But if you'd ever feel the urge to try the KMAL arm, I would gladly send it to you so you could inspect it/play with it for a couple of months. It's been sitting in a drawer for several years anyway. Just let me know off list.
Best,
Frank Schröder
Dear Mr Morsiani
Great thanks for providing this information! You are very generous with your knowledge. I was wondering, given a fixed distance between magnets, in what range would the attractive force between magnets need to be in order to provide the proper antiskating force?
I understand since unipivot arms have such low friction, this force must be reasonably small...
Regards,
Zach
Great thanks for providing this information! You are very generous with your knowledge. I was wondering, given a fixed distance between magnets, in what range would the attractive force between magnets need to be in order to provide the proper antiskating force?
I understand since unipivot arms have such low friction, this force must be reasonably small...
Regards,
Zach
Dear Capt Zach,
it is useless to know how much strong the antiskating force is,
this value is different for each set up,depending on the stylus pressure,the cartridge mass,the arm lenght.
Instead it is useful to know the effect of this force, is the pressure of the stylus balanced on the two sides of the groove?
When you know that this happens,the antiskating force is right.
How to know this?
An empyrical way is to look at the cantilever ,the force is balanced when the cantilever stays in centre of the cartridge body.
The best method is to have a dual trace oscilloscope,and a test disc with fixed frequency.
The pressure is balanced when the vawes of the two channel have the same amplitude.
When the antiskating force is too scarce,you will see distortion in the right channell.
The problem is that many test disc do not have a fixed frequency for all the disc side,so you can adjust correctly the antiskating for the zone in wich che arm is playing the test track.
And you can not know what will happen in other zones.
I have old Decca test disc with a fixed frequecy in all the side.
But in the real life it is not possible to adjust the antiskating with rare test disc and oscilloscope.
A flat uncutted disc can be used,adjusting the arm not to stay stopped,because the skate force in the cutted grooves is greater than in a flat disc,it is enough to adjust the antiskating to obtain a slow arm motion toward the outer of the disc.
Playing the vinyls,look at the cantilever if it is in the centre.
What will show you that the antiskating is right is that after 10 hours of playing the cantilever will be in centre as after 100 hours.
In too much cases I see cartridges with cantilver out of the centre,
generally toward right looking from the front side.
This is the condition of cartridges playing without antiskating,or with a too scarce antiskating.
In these cases the distortion rises up to 10%,this means mistraking,the life of the cartrige is shorter,and remeber that the diamond is harder than vinyl,the mistraking damages the cutted grooves irreversibly.
My method is empyrical,but with some pratice it is possible to obtain a satisfactory sound.
It is like to adjust the heads of a tape recorder by ears with a good heaphone ,I used to align the play head for pre-recorded tapes.
Best regards,Carlo Morsiani
it is useless to know how much strong the antiskating force is,
this value is different for each set up,depending on the stylus pressure,the cartridge mass,the arm lenght.
Instead it is useful to know the effect of this force, is the pressure of the stylus balanced on the two sides of the groove?
When you know that this happens,the antiskating force is right.
How to know this?
An empyrical way is to look at the cantilever ,the force is balanced when the cantilever stays in centre of the cartridge body.
The best method is to have a dual trace oscilloscope,and a test disc with fixed frequency.
The pressure is balanced when the vawes of the two channel have the same amplitude.
When the antiskating force is too scarce,you will see distortion in the right channell.
The problem is that many test disc do not have a fixed frequency for all the disc side,so you can adjust correctly the antiskating for the zone in wich che arm is playing the test track.
And you can not know what will happen in other zones.
I have old Decca test disc with a fixed frequecy in all the side.
But in the real life it is not possible to adjust the antiskating with rare test disc and oscilloscope.
A flat uncutted disc can be used,adjusting the arm not to stay stopped,because the skate force in the cutted grooves is greater than in a flat disc,it is enough to adjust the antiskating to obtain a slow arm motion toward the outer of the disc.
Playing the vinyls,look at the cantilever if it is in the centre.
What will show you that the antiskating is right is that after 10 hours of playing the cantilever will be in centre as after 100 hours.
In too much cases I see cartridges with cantilver out of the centre,
generally toward right looking from the front side.
This is the condition of cartridges playing without antiskating,or with a too scarce antiskating.
In these cases the distortion rises up to 10%,this means mistraking,the life of the cartrige is shorter,and remeber that the diamond is harder than vinyl,the mistraking damages the cutted grooves irreversibly.
My method is empyrical,but with some pratice it is possible to obtain a satisfactory sound.
It is like to adjust the heads of a tape recorder by ears with a good heaphone ,I used to align the play head for pre-recorded tapes.
Best regards,Carlo Morsiani
Dear Carlo,
I understand what you are saying about the variable in antiskate forces. However, my question is about the magnetic force that you utilized in your design. Given an arm of similar geometry, a certain magnetic force would need to be chosen in order to offer and acceptable range of adjustibility, and have the overall anstiskating force be appropriate to the arm and cartridge. If for instance, one utilized powerful rare earth magnets, the force might be too strong, and no amount of adjustability could get it into the appropriate range. BTW, where are you in Italy. Are you close to Tuscany. Im currently studying in Florence right now.
Thanks,
Zach
I understand what you are saying about the variable in antiskate forces. However, my question is about the magnetic force that you utilized in your design. Given an arm of similar geometry, a certain magnetic force would need to be chosen in order to offer and acceptable range of adjustibility, and have the overall anstiskating force be appropriate to the arm and cartridge. If for instance, one utilized powerful rare earth magnets, the force might be too strong, and no amount of adjustability could get it into the appropriate range. BTW, where are you in Italy. Are you close to Tuscany. Im currently studying in Florence right now.
Thanks,
Zach
Dear Capt Zach,
the sizie and the placement of the magnets in my arm is described in my previous posts.
But you can find the right magnets by experiments,exactly in the same way I manufactured my first arm .
You need an uncutted disc for rough adjustment,then a test disc with fixed frequency and a dual trace oscilloscope.
If you want to see and hear my arm working ,I have one customer in Florence .
We can arrange a meeting.
Write to my mail info@morsiani.it
Best regards,Carlo Morsiani.
the sizie and the placement of the magnets in my arm is described in my previous posts.
But you can find the right magnets by experiments,exactly in the same way I manufactured my first arm .
You need an uncutted disc for rough adjustment,then a test disc with fixed frequency and a dual trace oscilloscope.
If you want to see and hear my arm working ,I have one customer in Florence .
We can arrange a meeting.
Write to my mail info@morsiani.it
Best regards,Carlo Morsiani.
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