Happy Holidays to everyone !!!!
Perhaps a high end cartridge could be built into / on a linear arm wand where the concept could experimented on without the need the micro "surgery" in making a cartridge. It would be easier to work on an sealed up / shielded after completion. High end cantilevers with diamond mounted can be bought. Thinking outside the box or in this case the cartridge. Just a thought !!
Perhaps a high end cartridge could be built into / on a linear arm wand where the concept could experimented on without the need the micro "surgery" in making a cartridge. It would be easier to work on an sealed up / shielded after completion. High end cantilevers with diamond mounted can be bought. Thinking outside the box or in this case the cartridge. Just a thought !!
Personally, I like this one although I have never heard it.
DS Audio DS Master1 Optical CartridgeMusical Surroundings
I have been modifying Denon DL-103R for a while. DL-103R is a low compliance MC cartridge. Medium and low compliance MC cartridges work extremely well with linear arms. It is perfect to listen to jazz with my modified DL-103R with my air bearing linear arms. But for classical music, it somewhat lacks texture in the mid range frequency.
DS Audio DS Master1 Optical CartridgeMusical Surroundings
I have been modifying Denon DL-103R for a while. DL-103R is a low compliance MC cartridge. Medium and low compliance MC cartridges work extremely well with linear arms. It is perfect to listen to jazz with my modified DL-103R with my air bearing linear arms. But for classical music, it somewhat lacks texture in the mid range frequency.
I just google more.
Here are some more fun projects. Appears to be DIY efforts on the Neumann DST.
This site needs to be translated from Japanese but it's full of info!
Oops, I'm off topic again! Please go back to your regular program!
I have listened to the previous version last year.. To be honest it seems good for certain aspects such as distortion on highly modulated passages and also seems to be quieter.
Nevertheless, the sound was bloomy with an edge on the upper register. It didn't sound too natural and neutral to me.
However, if the price is factored in with phono and cartridge at 7-8K total, I think it was a bargain and not sure much, much better could have been done at that price point, maybe only in term of natural and flow of sound pretty much!
They might have improved upon the precious one, so this one could be interesting and also looks like it has an interesting chassis for the phono section, so I am not sure and I hope to listen to it next April at the Axpona Audio show!
EDIT: I haven't listened to it last year but two years ago and this model was already available last year at a substantial 20K. I probably did not stop listening to it as I though it was the same product I have already auditioned and didn't like very much. So this next show I will definitely go listen to it with careful attention!
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Still having a good Christmas
To bring us back on Topic again then ......
...... Being the owner of ‘my version’ of Tom's Floater (it is truly amazing), I enjoyed reading the comments between Tom & Niffy I couldn't keep up fully with either of them re. resonance however, I still enjoy making other’s designs
I am now at the final tuning stage, temp. fixed on my modified 'Old' Rega Planer 3, alongside my Roksan Tabriz 'Z'
I have not yet made a direct comparison to any other arm but, I do like this one very much.
You can see from the pics. that I have used the Pin Bearing approach, which is working perfectly on 4mm glass.
I came back from London [Tuesday] with my family after seeing the Musical 'Beautiful' (What a fantastic show) & have just finished listening to her (Carole King) Tapestry LP using my 'copy of Niffy's Black Stealth Bomber Arm'
It's my Wife's LP she had when she was a teenager but I am not allowed to tell you how long ago that was!!!!
It sounded great & IF I get time to compare with other arms I have, then I will write it up for you all.
GC
ps. Anyone else made the ‘Niffy’ version???
pps. Good to hear from you Tom; are you still getting out on the Push bike?
To bring us back on Topic again then ......
...... Being the owner of ‘my version’ of Tom's Floater (it is truly amazing), I enjoyed reading the comments between Tom & Niffy I couldn't keep up fully with either of them re. resonance however, I still enjoy making other’s designs
I am now at the final tuning stage, temp. fixed on my modified 'Old' Rega Planer 3, alongside my Roksan Tabriz 'Z'
I have not yet made a direct comparison to any other arm but, I do like this one very much.
You can see from the pics. that I have used the Pin Bearing approach, which is working perfectly on 4mm glass.
I came back from London [Tuesday] with my family after seeing the Musical 'Beautiful' (What a fantastic show) & have just finished listening to her (Carole King) Tapestry LP using my 'copy of Niffy's Black Stealth Bomber Arm'
It's my Wife's LP she had when she was a teenager but I am not allowed to tell you how long ago that was!!!!
It sounded great & IF I get time to compare with other arms I have, then I will write it up for you all.
GC
ps. Anyone else made the ‘Niffy’ version???
pps. Good to hear from you Tom; are you still getting out on the Push bike?
Attachments
Hi Geoff,
Nice looking arm, looks kinda familiar.
A couple of questions. Well more than a couple.
What is the total mass including cartridge?
What thickness of carbon fibre sheet did you use? It looks thicker than the 0.75mm I used. I notice that you have aligned the outer weave at 0/90°, I had my carbon fibre specially laid up with the surface at +/-45° and the inner at 0°. It's slightly counterintuitive but the +/-45° layup is actually significantly more rigid longitudinally and torsionally than 0/90°.
Did you use balsa cores and if so did you use it end grain?
How are the cables exited?
What are you using for bearings? Are they jewelled?
How is the rail moved to facilitate record changing?
Most importantly how does it sound?
It's great to see a copy of the arm. I hope you enjoy it as much as I enjoy mine.
Niffy
Nice looking arm, looks kinda familiar.
A couple of questions. Well more than a couple.
What is the total mass including cartridge?
What thickness of carbon fibre sheet did you use? It looks thicker than the 0.75mm I used. I notice that you have aligned the outer weave at 0/90°, I had my carbon fibre specially laid up with the surface at +/-45° and the inner at 0°. It's slightly counterintuitive but the +/-45° layup is actually significantly more rigid longitudinally and torsionally than 0/90°.
Did you use balsa cores and if so did you use it end grain?
How are the cables exited?
What are you using for bearings? Are they jewelled?
How is the rail moved to facilitate record changing?
Most importantly how does it sound?
It's great to see a copy of the arm. I hope you enjoy it as much as I enjoy mine.
Niffy
Tiffy Response
Hi Niffy,
From the top then ......
Total mass fairly heavy, just short of 60gms.
The c/f was leftover from the garage junk bin @ 1.5mm
Balsa core end grain used, each layer @ 90deg
As I have it mounted temporary on my Rega, the wiring comes out of the brass tube & terminates direct into my Phono RCA's. The wires laying over the Tabriz Z arm
Bearings cheap & cheerful - Stainless wheels; Ally with only small countersink [no jewel]; & Ballpoint Pen tips. I accept your advice re marked difference in sound with the jewels etc. but for me it is working very well so far & it was Very cheap
The Stealth as is - mounted in place using a couple of clips I made; so just remove clips & the whole unit moves to the side ..... Simples! I havn't decided how to mount it to my main system yet so I don't need to use the 4mm screw which contacts on keyway of shaft
& the big question - How does it sound? Very pleased with the results, it's big test to come when I get the chance to compare it with Tom's 'Floater'
Thanks to you for the idea - the continueing project is keeping me Happy
GC
Hi Niffy,
From the top then ......
Total mass fairly heavy, just short of 60gms.
The c/f was leftover from the garage junk bin @ 1.5mm
Balsa core end grain used, each layer @ 90deg
As I have it mounted temporary on my Rega, the wiring comes out of the brass tube & terminates direct into my Phono RCA's. The wires laying over the Tabriz Z arm
Bearings cheap & cheerful - Stainless wheels; Ally with only small countersink [no jewel]; & Ballpoint Pen tips. I accept your advice re marked difference in sound with the jewels etc. but for me it is working very well so far & it was Very cheap
The Stealth as is - mounted in place using a couple of clips I made; so just remove clips & the whole unit moves to the side ..... Simples! I havn't decided how to mount it to my main system yet so I don't need to use the 4mm screw which contacts on keyway of shaft
& the big question - How does it sound? Very pleased with the results, it's big test to come when I get the chance to compare it with Tom's 'Floater'
Thanks to you for the idea - the continueing project is keeping me Happy
GC
To Swing Or Not To Swing
Here are two videos showing the same mechnical linear tonearm, one with a fixed headshell and one with a pivot or swing headshell (a la RS Labs). The test record obviously is slightly eccentric as you can see the wavering of whole arm assembly on the arm with fixed headshell. And the one with pivot/swing headshell wavering of the headshell and dragging the assembly and there's noticeable roller bearings sticking, not very smooth. Whatever conclusion you can draw from them, at least you can see their dynamic behaviors. The test tone is also audibly different. If the test record is perfectly concentric, will the two arms track the same, at least visually?
Video with fixed headshell
Video with swing headshell
I also wonder if the signal wires introduce some compliance to the motion as the headshell video shows some horizontal "bounce."
In the end, what is more desirable? Also the swinging arm reminds me of the "floating" arm that it introduces pivot motion.
Just thinking out loud...
Here are two videos showing the same mechnical linear tonearm, one with a fixed headshell and one with a pivot or swing headshell (a la RS Labs). The test record obviously is slightly eccentric as you can see the wavering of whole arm assembly on the arm with fixed headshell. And the one with pivot/swing headshell wavering of the headshell and dragging the assembly and there's noticeable roller bearings sticking, not very smooth. Whatever conclusion you can draw from them, at least you can see their dynamic behaviors. The test tone is also audibly different. If the test record is perfectly concentric, will the two arms track the same, at least visually?
Video with fixed headshell
Video with swing headshell
I also wonder if the signal wires introduce some compliance to the motion as the headshell video shows some horizontal "bounce."
In the end, what is more desirable? Also the swinging arm reminds me of the "floating" arm that it introduces pivot motion.
Just thinking out loud...
@directdriver,
An eccentric record is a catastrophe for a tangential tonearm. However, when the eccentricity is below 0,1 mm the to and fro movement is reduced to a “stop and start” movement (because the distance between 2 adjacent grooves is about 0,1 mm). See the diagram about the influence of the eccentricity in relation to the stability of the frequencies. The alternating sound in both videos shows that the effect – represented in the diagram – is real.
The linearity of a tonearm is important – the tip of the stylus at right angles to the spindle of the platter – but the most important property is the freedom of the tonearm. When the tonearm is not perfect tangential it influences the start and end of the highest vibrations (frequencies) of the modulated groove. Thus one of the channels starts and ends a certain frequency a bit earlier. Fortunately, we cannot hear high frequencies (> 10 kHz) very well.
However, when the tonearm is rigid in the sideward directions (by construction/by mass), the stylus is forced to move within a “straight jacket”. The video’s show the sideward force to the tip of the stylus because we see the cantilever “bow” to both directions (the fixed headshell the most). The only way to reduce this big disadvantage of a tangential tonearm is centring records. A servo mechanism will help to reduce this force for the whole trajectory of the tonearm but it cannot eliminate the sideward forces by the eccentricity of the record. In other words, there are 2 disadvantages: a pulsating frequency during every turn of the platter by the eccentricity of the record and a deformation of the stereo amplitudes by the sideward push of the walls of the groove. The “swing headshell” will reduce the influence of the latter a bit.
An eccentric record is a catastrophe for a tangential tonearm. However, when the eccentricity is below 0,1 mm the to and fro movement is reduced to a “stop and start” movement (because the distance between 2 adjacent grooves is about 0,1 mm). See the diagram about the influence of the eccentricity in relation to the stability of the frequencies. The alternating sound in both videos shows that the effect – represented in the diagram – is real.
The linearity of a tonearm is important – the tip of the stylus at right angles to the spindle of the platter – but the most important property is the freedom of the tonearm. When the tonearm is not perfect tangential it influences the start and end of the highest vibrations (frequencies) of the modulated groove. Thus one of the channels starts and ends a certain frequency a bit earlier. Fortunately, we cannot hear high frequencies (> 10 kHz) very well.
However, when the tonearm is rigid in the sideward directions (by construction/by mass), the stylus is forced to move within a “straight jacket”. The video’s show the sideward force to the tip of the stylus because we see the cantilever “bow” to both directions (the fixed headshell the most). The only way to reduce this big disadvantage of a tangential tonearm is centring records. A servo mechanism will help to reduce this force for the whole trajectory of the tonearm but it cannot eliminate the sideward forces by the eccentricity of the record. In other words, there are 2 disadvantages: a pulsating frequency during every turn of the platter by the eccentricity of the record and a deformation of the stereo amplitudes by the sideward push of the walls of the groove. The “swing headshell” will reduce the influence of the latter a bit.
Hi,
It's not necessarily the tonearm that you want to keep tangential but definitely is the cantilever. Allowing the armtube a bit of rotation can help to keep the cantilever more tangential. A tenth of a millimetre stylus movement taken up entirely by the cantilever will result in greater lateral tracking error that if the same stylus movement is accommodated by the rotation of the length of the tonearm. However spitting the arm into a lateral carriage and rotating armtube is going to compromise the structure of the arm and will almost certainly cause more problems than it solves. Tom's floating arm is probably a much better way of achieving this as the arm remains a single structure.
The cantilever deflection due to the mass of the carriage moving back and forth with eccentricity is not anywhere as great as many people seem to think. The maximum side force applied to the stylus required to accelerate the carriage back and forth is easy to calculate. It's simply F=M x a x ω^2. Where M is carriage mass in kg, a is the amplitude of the eccentricity in metres and ω is the rotational speed in radians/second (3.49rads/s at 33 1/3 rpm). If you know the compliance of your cartridge and the length of the cantilever it is easy to ascertain the cantilever deflection angle. Unless the carriage is very heavy, the compliance high and the eccentricity great the deflection of the cantilever due to eccentricity will be low/insignificant. Only if the cantilever resonance is so low that it is similar to the rotational speed of the record will you have a problem and that's just poor design. The cantilever deflection due to bearing friction will to be of much greater significance. (unless you have an air bearing)
Niffy
It's not necessarily the tonearm that you want to keep tangential but definitely is the cantilever. Allowing the armtube a bit of rotation can help to keep the cantilever more tangential. A tenth of a millimetre stylus movement taken up entirely by the cantilever will result in greater lateral tracking error that if the same stylus movement is accommodated by the rotation of the length of the tonearm. However spitting the arm into a lateral carriage and rotating armtube is going to compromise the structure of the arm and will almost certainly cause more problems than it solves. Tom's floating arm is probably a much better way of achieving this as the arm remains a single structure.
The cantilever deflection due to the mass of the carriage moving back and forth with eccentricity is not anywhere as great as many people seem to think. The maximum side force applied to the stylus required to accelerate the carriage back and forth is easy to calculate. It's simply F=M x a x ω^2. Where M is carriage mass in kg, a is the amplitude of the eccentricity in metres and ω is the rotational speed in radians/second (3.49rads/s at 33 1/3 rpm). If you know the compliance of your cartridge and the length of the cantilever it is easy to ascertain the cantilever deflection angle. Unless the carriage is very heavy, the compliance high and the eccentricity great the deflection of the cantilever due to eccentricity will be low/insignificant. Only if the cantilever resonance is so low that it is similar to the rotational speed of the record will you have a problem and that's just poor design. The cantilever deflection due to bearing friction will to be of much greater significance. (unless you have an air bearing)
Niffy
Thanks to responses and pointers from Tom & Niffy. It is the straitjacket behavior of parallel trackers (I use the word "parallel" to distinguish it from pivoting type of tangential arm a la Thales, Garrard, etc...) that makes me want alternatives. I agree with Niffy that keeping the cantilever tangent is more important than the tonearm. One way is to make the carriage and/or armtube extreme short and low mass a la Niffy's approach or to add an extra pivot which, as Niffy pointed out, can compromise the structural integrity and adding unwanted vibration. I would have preferred the parallel tracker in the video to have the pivot point at the center of the slider which would function closer to the "floating" arm.
(I'm a lazy person so I'm obviously in the camp for convenience with pivoting tangential arms over parallel arms and I am not a "neutral" person and perfectly fine with some intentional coloration of the signal. What I can't stand is the grainy sound in tracking distortion that can be audible even in expensive tonearms!)
I just want to add that, after some research from the swing headshell maker's website, I discovered whatever observations we gain from the two videos must taking into account that the pivoting headshell has two springs on the sides, hence the bouncing movement! No wonder the carriage slides so awkwardly! This seems to open up another can of worms and I can't quite figure out their reasoning, quoted below, and they have a patent on this! In sum, an idiosyncratic product to say the least.
Once again, thanks to Tom & Niffy that I learned so much from both of you!
Care to elaborate on that? If you are talking about traditional pivot tonearm (ie, with a single fixed horizontal pivot point and headshell offset angle and overhang), then yes, it would have inherent tracking errors. Back to the swing headshell, I would think having extra pivot IS to reduce cantilever stress. Is reducing friction the only answer? Shouldn't mass be taken into account?
(And what about articulated tonearms with extra pivot(s) a la Thales, Schroeder LT, JR audio, etc...? Most of them have no overhang. Pivot arms always have the innate advantage of low horizontal mass. They all have skating force to some degrees, however low, so that needs to be addressed. The Schroeder LT claims to be almost non-existent. So it can be done, I think. But this is a thread about parallel tracking designs so we don't need to go there.)
Is this an advantage? I believe that one of the advantages of linear tracking arms is that you can have higher lateral effective mass. Low frequencies are cut laterally only to prevent the stylus from jumping out of the groove on loud low frequency passages. Having higher lateral effective mass is definitely beneficial in reproduction of low frequencies. Vertical effective mass has to be kept lower due to warps.
Having massively different vertical and horizontal effective masses could create a problem in crosstalk between the channels. However as long as the ratio of the masses is kept below about 4 this isn't a problem as by the time that there is significant vertical modulation, about 120hz, the amount of crosstalk would be down to about -30dB, greater than the channel separation of your cartridge. The amount of crosstalk decreases from this point by about 12dB/octave so by the time you get to frequencies where there is significant stereo information the amount of crosstalk would be utterly insignificant.
The benefits of greater lateral control of the cartridge outweighs any crosstalk issues as they are inaudible.
Having different vertical and horizontal effective masses does not cause any additional distortions.
Niffy
I should rephrase it then as:"Pivot arms always have the innate advantage of EASIER to control horizontal mass because it is low to begin with and you can always add more mass accordingly." I guess in that case the way to do it in a pivot arm would be similar to the Dynavector "split plane" design.
All the opinions I am going to explain are only referring to linear tracking arms.
In order to express my view effectively, I did a diagram. Let's assume the force to pull the cartridge inward is F. I also assume that F is the function of many factors. So I get line F1 F2. The pulling force keeps increasing and finally it pulls the arm carriage towards the center of record. On the diagram, at point A the pulling force is equal to the friction of arm carriage. The friction is a function of many factors including mass, so I don't need to deal with mass here. At A, the carriage won't move. Above A in the gray shadow area, the pulling force is stronger than friction. So, the arm carriage moves. Under point A, the pulling force is smaller than friction, so the arm carriage doesn’t move.
Now, let’s examine the swing head shell. Let’s assume that the springs start to engage at C. The springs have too low compliance. In other word, it is too strong and useless because the arm carriage is already moving.
If the springs start to engage at point B, the head shell will NOT be tangent to the groove. The springs are engaged by the pulling force F before the arm carriage starts to move. Tracking errors will occur. The cantilever will be stressed.
However, the worst is not over yet. As we all know that cartridge is a mechanic device. The constant vibration of two springs will transmit to the head shell. I believe such vibration will generate a signal at certain frequencies. These frequencies will add on the vibration of cantilever. It is another kind of stress on cantilever. It will add and distort the information in the grooves. I don’t have experiment to prove my view, but it is very possible.
I said as long as you can reduce the friction. You don’t need swing head shell. Let’s see the diagram 2. Point A is now under the point B. It means friction is low and small pulling force will move the carriage. It also means that the pulling force which is equal to friction is under the point at which the springs start to engage. So, the springs are useless. It will only generate unwanted frequencies.
My conclusion is swing head shell is a bad idea beside it comprises the integrity of arm structure.
In order to express my view effectively, I did a diagram. Let's assume the force to pull the cartridge inward is F. I also assume that F is the function of many factors. So I get line F1 F2. The pulling force keeps increasing and finally it pulls the arm carriage towards the center of record. On the diagram, at point A the pulling force is equal to the friction of arm carriage. The friction is a function of many factors including mass, so I don't need to deal with mass here. At A, the carriage won't move. Above A in the gray shadow area, the pulling force is stronger than friction. So, the arm carriage moves. Under point A, the pulling force is smaller than friction, so the arm carriage doesn’t move.
Now, let’s examine the swing head shell. Let’s assume that the springs start to engage at C. The springs have too low compliance. In other word, it is too strong and useless because the arm carriage is already moving.
If the springs start to engage at point B, the head shell will NOT be tangent to the groove. The springs are engaged by the pulling force F before the arm carriage starts to move. Tracking errors will occur. The cantilever will be stressed.
However, the worst is not over yet. As we all know that cartridge is a mechanic device. The constant vibration of two springs will transmit to the head shell. I believe such vibration will generate a signal at certain frequencies. These frequencies will add on the vibration of cantilever. It is another kind of stress on cantilever. It will add and distort the information in the grooves. I don’t have experiment to prove my view, but it is very possible.
I said as long as you can reduce the friction. You don’t need swing head shell. Let’s see the diagram 2. Point A is now under the point B. It means friction is low and small pulling force will move the carriage. It also means that the pulling force which is equal to friction is under the point at which the springs start to engage. So, the springs are useless. It will only generate unwanted frequencies.
My conclusion is swing head shell is a bad idea beside it comprises the integrity of arm structure.
Attachments
Well, I don’t like to make people unhappy but let’s look to the advantages of tangential tonearms.
First of all, a tangential tonearm is a tonearm that moves the tip of the stylus in a straight line from the outside to the inside of the record. A linear tonearm moves the tip of the stylus at right angles to the radians of the centre of the record. Thus a tangential tonearm is a linear tonearm too, but a linear tonearm is not a tangential tonearm.
The purpose of a cartridge is to reproduce the modulations of the groove. Modulations that are cut into a master by the stylus of the cutting machine. The sidewards movement of the cutting machine has nothing to do with the modulation transfer of the cutter stylus itself. It has a mechanical sidewards movement that can be adjusted to get a desired amount of adjacent grooves within a certain distance (e.g. 75 at 1 inch).
So when we want to reproduce the modulations of the groove we have to eliminate every force that isn’t equal to the movements of the stylus of the cutting head of the cutting machine. However, we cannot separate the modulation from the inwards movement of the cartridge because the distance between 2 adjacent grooves is not always the same.
Now the question is how we can move a tangential tonearm without too much influences to the tip of the stylus. You can try to design a low friction, low mass tangential tonearm but that’s not “the perfect solution”. So what must we do to get a better tangential tonearm?
First of all we have to design the “sidewards mover” of the tonearm and second we have to damp this tonearm because the mass of a phono cartridge is not equal to the cutterhead of a record cutting machine.
To move the cartridge we need bandwidth. The distance between 2 adjacent grooves is about 0,1 mm and the distance between the outer modulated groove and the inner modulated groove is about 86 mm. So when we want to transfer the tonearm 0,1 mm at the time our servo mechanism must be capable to produce 860 serried steps to move the tonearm.
When we design a tangential tonearm with a pivot the length of the armtube is really important in relation to the bandwidth. A very short armtube cannot move smooth by increments of 0,1 mm. So we have to improve our bandwith (e.g. 0,01 mm) or the length of the tonearm/armtube.
It is easy to detect the misalignment of the tonearm to drive the servo mechanism. You only need a light source and a photo receiver. The light source is at right angles to the tangential transportation mechanism and the photo receiver is mounted on/in the armtube. When the armtube is not at the right position the output of the photo receiver decreases and the servo motor moves “1 step” to eliminate the misalignment.
However, between 2 steps of the servo mechanism the tonearm is moved by… the outer wall of the groove. Thus the tonearm/armtube must have a very low mass to get the desired high quality of the output of the cartridge. You cannot avoid this because the eccentricity of the record forces the servo mechanism to move the tonearm to and fro during every turn of the platter.
So what is the difference between a tonearm with a fixed pivot and a tangential tonearm? Not really much and that’s why most high end tonearms are just fixed pivot tonearms.
When we think it over we have to conclude that the most important “enhancement” of a tangential tonearm (with or without servo mechanism) is the centring of the record. All the mechanical improvements are negligible in relation to the “destructive” influence of eccentricity to the performance of the tangential tonearm.
And last but not least: the phono cartridge. A 12 inch record recorded at 45 rpm has far more detail than a 33 rpm record with the same music. Just because most phono cartridges are not “sensible” enough to reproduce all the details at 33 rpm. I have some high-quality 45 rpm 12 inch records and when I listen to these records it is like I have just bought a really high end cartridge. I have an MC Ortofon Cadenza red so it is not “the worst cartridge in town” at 33 rpm. But despite of this I can hear a big difference in the quality of the output signal.
First of all, a tangential tonearm is a tonearm that moves the tip of the stylus in a straight line from the outside to the inside of the record. A linear tonearm moves the tip of the stylus at right angles to the radians of the centre of the record. Thus a tangential tonearm is a linear tonearm too, but a linear tonearm is not a tangential tonearm.
The purpose of a cartridge is to reproduce the modulations of the groove. Modulations that are cut into a master by the stylus of the cutting machine. The sidewards movement of the cutting machine has nothing to do with the modulation transfer of the cutter stylus itself. It has a mechanical sidewards movement that can be adjusted to get a desired amount of adjacent grooves within a certain distance (e.g. 75 at 1 inch).
So when we want to reproduce the modulations of the groove we have to eliminate every force that isn’t equal to the movements of the stylus of the cutting head of the cutting machine. However, we cannot separate the modulation from the inwards movement of the cartridge because the distance between 2 adjacent grooves is not always the same.
Now the question is how we can move a tangential tonearm without too much influences to the tip of the stylus. You can try to design a low friction, low mass tangential tonearm but that’s not “the perfect solution”. So what must we do to get a better tangential tonearm?
First of all we have to design the “sidewards mover” of the tonearm and second we have to damp this tonearm because the mass of a phono cartridge is not equal to the cutterhead of a record cutting machine.
To move the cartridge we need bandwidth. The distance between 2 adjacent grooves is about 0,1 mm and the distance between the outer modulated groove and the inner modulated groove is about 86 mm. So when we want to transfer the tonearm 0,1 mm at the time our servo mechanism must be capable to produce 860 serried steps to move the tonearm.
When we design a tangential tonearm with a pivot the length of the armtube is really important in relation to the bandwidth. A very short armtube cannot move smooth by increments of 0,1 mm. So we have to improve our bandwith (e.g. 0,01 mm) or the length of the tonearm/armtube.
It is easy to detect the misalignment of the tonearm to drive the servo mechanism. You only need a light source and a photo receiver. The light source is at right angles to the tangential transportation mechanism and the photo receiver is mounted on/in the armtube. When the armtube is not at the right position the output of the photo receiver decreases and the servo motor moves “1 step” to eliminate the misalignment.
However, between 2 steps of the servo mechanism the tonearm is moved by… the outer wall of the groove. Thus the tonearm/armtube must have a very low mass to get the desired high quality of the output of the cartridge. You cannot avoid this because the eccentricity of the record forces the servo mechanism to move the tonearm to and fro during every turn of the platter.
So what is the difference between a tonearm with a fixed pivot and a tangential tonearm? Not really much and that’s why most high end tonearms are just fixed pivot tonearms.
When we think it over we have to conclude that the most important “enhancement” of a tangential tonearm (with or without servo mechanism) is the centring of the record. All the mechanical improvements are negligible in relation to the “destructive” influence of eccentricity to the performance of the tangential tonearm.
And last but not least: the phono cartridge. A 12 inch record recorded at 45 rpm has far more detail than a 33 rpm record with the same music. Just because most phono cartridges are not “sensible” enough to reproduce all the details at 33 rpm. I have some high-quality 45 rpm 12 inch records and when I listen to these records it is like I have just bought a really high end cartridge. I have an MC Ortofon Cadenza red so it is not “the worst cartridge in town” at 33 rpm. But despite of this I can hear a big difference in the quality of the output signal.
As I said earlier, I did NOT know there were springs on both sides of the headshell. I found out only AFTER I posted the videos. I agree that using springs is probably not a good idea and the video demonstrates the awkward stuttering movement of the carriage. But my question was referring to why having extra pivot would stress the cantilever when some members here think, as Niffy pointed out, that "allowing the armtube a bit of rotation can help to keep the cantilever more tangential" at the expense of structural integrity.
I would like to see the pivot point located at the center of the carriage, which may or may not resemble the floating unipivot arm (or Frank Schröder's DIY arm shown in post#1517 and his explanation in post#1538).
I think you might have got the words tangential and linear the wrong way around.
True, but much more important is the eccentricity of the record.
The need to damp the arm has nothing to do with the difference in mass between the cutterhead and cartridge. The cutterhead is made massive so that the centre of the generator that modulates the cutting stylus remains as stationary as possible so that the neutral axis of the groove is not modulated, (this of course excluds the slow inward movement). Similarly the body of the cartridge is held as stationary as possible relative to the neutral axis of the groove by the mass/effective mass of the arm. A higher mass will move less. Making this mass high may reduce the compliance resonant frequency to a point where it is excited by warps and eccentricity. This is what requires damping. If records were made perfectly concentric and flat very high effective masses would be desirable and no damping of arm movement would be required. [/QUOTE]
You are now introducing the servo control which does require a swivel type arm to operate. The swivel head arm being discussed is not servo controlled but is passive. Servo control can work well but tends to introduce as many problems as it solves.
True. But linear tracking arms ARE very different from fixed pivot and pivoted tangential arms
Accurately centring the record is important. However as warps tend to occur at a higher frequency than eccentricity they are more likely to excite compliance resonance and require the vertical effective mass to be reduced to sub-optimum levels. I think that good clamping/warp flattening is more important.
45rpm records can indeed sound much better than the 33 1/3 version. I have Peter Gabriel So in both and the difference is huge.
Niffy