Two days ago I had the opportunity to participate in a listening session in which one of the variables was a pure straight arm (Fidelix 0 SideForce), along with a prototype version of the same design (with offset angle). The bearing is a unipivot with a hanging extension that stabilizes rocking tendencies in a manner similar to the Simon Yorke. Both tonearm versions use universal headshells, making it easy to compare them with the same cartridge.
I felt that the offset angle version was a little cleaner-sounding in the mid and upper frequencies, but lost out in a substantial way when it came to dynamic range, transient impact and pitch stability.
The designer agreed, and said that the listening results were why he never put the offset angle version into production (although that was his initial plan).
The cartridges used were a Fidelity Research FR-1 Mk2 (with elliptical stylus), and a JVC MC-L1000 (with Shibata stylus).
IMHO, it is worth listening to a pure straight tonearm such as the Viv Rigid Float, if for no other reason than to educate your ears regarding what having an offset angle does for the sound, and does to the sound.
I felt that the offset angle version was a little cleaner-sounding in the mid and upper frequencies, but lost out in a substantial way when it came to dynamic range, transient impact and pitch stability.
The designer agreed, and said that the listening results were why he never put the offset angle version into production (although that was his initial plan).
The cartridges used were a Fidelity Research FR-1 Mk2 (with elliptical stylus), and a JVC MC-L1000 (with Shibata stylus).
IMHO, it is worth listening to a pure straight tonearm such as the Viv Rigid Float, if for no other reason than to educate your ears regarding what having an offset angle does for the sound, and does to the sound.
Bingo! What you are hearing in terms of transient impact and pitch stability in arms such as the Viv Rigid Float is the reduction of horizontal mode stylus scrubbing that you achieve by eliminating the offset angle. This scrubbing causes FM distortion, which translates into pitch instability, which is measurable and audible. This has been discussed in the DIY "Turntable Speed Stability Thread".
Yes, the offset angle both "does for" and "does to", but the "does to" can be eliminated without giving up the "does for" benefits. The Viv Labs design says that you have accept and tolerate tracking distortion in exchange for giving up the "does for" benefits of reducing tracking error with an offset angle. You can achieve both concurrently, but not with the Viv Labs design.
I could go into more detail, but I feel we are really getting off topic. The Viv Labs Rigid Float is not a tangential pivot tonearm, and is in fact not tangential at all.
Ray K
For an arm without off set angle, there are three possible situations.
If overhang is larger than 0, there are no null points at all. The arm will skate towards the center of platter.
If overhang is equal to 0, the null point is at exactly on the center of platter.
If overhang is less 0, in other word, it is underhang, there is only one null point. There is no skating on the null point.
Eliminating off set angle can't completely get rid of skating force. However, it may reduce skating force. So, it doesn't make sense to me to add more tracking errors in the meantime skating force still exists.
Listening is very subjective. If you use a regular pivot arm without any alignments, it can play, too. It can be very dynamic as well.
If overhang is larger than 0, there are no null points at all. The arm will skate towards the center of platter.
If overhang is equal to 0, the null point is at exactly on the center of platter.
If overhang is less 0, in other word, it is underhang, there is only one null point. There is no skating on the null point.
Eliminating off set angle can't completely get rid of skating force. However, it may reduce skating force. So, it doesn't make sense to me to add more tracking errors in the meantime skating force still exists.
Listening is very subjective. If you use a regular pivot arm without any alignments, it can play, too. It can be very dynamic as well.
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The Viv arm uses detachable headshell and one can easily compare straight headshell with a angled one a la Denon or Graham Robin (or any tonearm with Schroeder style rotatable headshell). It would be an even more accurate comparison so you don't have to use a bent armwand, especially on a unipivot that can upset the mass distribution.
Straight arm has been in around even in DJ world so that's nothing new. And, again, RS Labs uses an underhang geometry just like the Viv but with a pivoting headshell.
There's even a YouTube video showing an extremely long arm with straight headshell.
I haven't tried such experiment and I am sure it can be revealing. I just want to point out that in my response to G Doggett, my intent was not dismissive of such approach (and I might even like the sound!) but only in arguing that in search of tangency we are NOT "wasting our time on this quest" just because the Viv arm gets rave reviews.
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As to straight arm with no offset angle, it is completely incorrect to state it is free of skating force. If you make drawings and take a look at vectors in the beginning, in the middle , and in the end of record, you will see skating forces in all three set-ups ( overhang, zero overhang, and under-hang). So, in terms of parasitic lateral forces, straight arms do not have any advantages. Results aren't worthy severely increased angular mistakes. Sure, it is my opinion, based on plane geometry and basics of school physics.
Seems that we are wasting time since a long time: this paper comes from 1907!
https://worldwide.espacenet.com/pub...T=D&ND=3&date=19080515&DB=EPODOC&locale=en_EP
Then came Loefgren 1924, Baerwald 1938, Stevenson and all the others you know, till us. If tracking error was considered a real problem when steel nails were plowing shellac grooves on horn gramophones, difficult to consider acceptable now.
"Sounding good is different from sounding right" says wisely Dd. And sounding different from references - imho - is the first symptom of a wrong sounding.
Here instead would be interesting to discuss the for and to sound effects of tracking error and offset; separately and in their relationship.
carlo
https://worldwide.espacenet.com/pub...T=D&ND=3&date=19080515&DB=EPODOC&locale=en_EP
Then came Loefgren 1924, Baerwald 1938, Stevenson and all the others you know, till us. If tracking error was considered a real problem when steel nails were plowing shellac grooves on horn gramophones, difficult to consider acceptable now.
"Sounding good is different from sounding right" says wisely Dd. And sounding different from references - imho - is the first symptom of a wrong sounding.
Here instead would be interesting to discuss the for and to sound effects of tracking error and offset; separately and in their relationship.
carlo
Maybe, I judge to strict, nevertheless, I consider designs and products, based on pure ignorance, unacceptable, as well, as reviews of so called experts. Of course, there were a lot of breakthrough technical products, coming from dilettantes (as Sam Colt's 6-shooter and John Gartling gun). Sometimes dilettantism 
excels over narrow-minded professionalism, and excels dramatically. But, elite, expensive,"breakthrough" products, based on not knowing basics of 6-7 grade school disciplines, you name it...
Back to topic
Carlo, how is your project?
excels over narrow-minded professionalism, and excels dramatically. But, elite, expensive,"breakthrough" products, based on not knowing basics of 6-7 grade school disciplines, you name it...Back to topic
Carlo, how is your project?
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Hi Walter,
Maybe I misunderstood, but your statement that an arm with no offset angle "sees" a skating force even at the single zero/null point it is supposed to be aligned for(with underhang...) is not correct. One fun exercise with the Vivlabs arm is to move it so that it shows zero to little tangential error at the first(or last) track of the record, then move it back to where the designer tells you to leave it permanently, play back the same track and compare...
My LT arm will pass the thread test if one pulls with about the same force that the stylus/record interface generates. It will not show a preferential position on a blank record(yes - I know, friction will be slightly lower on a blank disc vs a modulated disc...). But it will move if you merely breathe in its direction
I've build about a dozen CB and BA arm with a rotating headshell plate that is magnetically centered so it doesn't "wiggle" around as it pleases(so to speak) but will be kept at the correct offset angle when operating without disturbence. The "stiffness" of the magnetic coupling is adjustable, to be set so the fres of the cartridge/headshell plate vis-avis the entire eff. mass of the arm minus said rotating parts is the same as the total arm cartridge resonance frequency in the lateral plane. You now have a damped antiresonator that will "cut" the arm/cartridge resonance frequency in the lateral plane to near immeasurability. More importantly, since all frequencies below 100Hz(and sometimes higher than that) are summed to mono before cutting a record, all low frequency info is strictly equal to lateral displacement. If such low frequency excitement=displacement of the arm occurs, it is the headshell that moves(rotates) laterally, not the stylus, so no signal is generated at/near the lateral fres of such arm. Many detrimental influences on the soundquality of vinyl playback, like stepup transformer saturation, phonostage overload, intermodulation distorsion, woofer "pumping" etc. are greatly diminished. Read: cleaner bass, likely cleaner upper frequency rendering as well.
Many rotating headshell designs are credited with reducing the "pinching effect", see:
Pinch Effect Distortion Calculator - Vinyl Engine
or:
LP distortion mechanisms
So far my findings show a reduction of the pinching distorsions at the price of (frequency-dependent)truncated dynamics unless you place the stylus in the rotation axis of the headshell.
Time for breakfast...
Cheerio,
Frank
Maybe I misunderstood, but your statement that an arm with no offset angle "sees" a skating force even at the single zero/null point it is supposed to be aligned for(with underhang...) is not correct. One fun exercise with the Vivlabs arm is to move it so that it shows zero to little tangential error at the first(or last) track of the record, then move it back to where the designer tells you to leave it permanently, play back the same track and compare...
My LT arm will pass the thread test if one pulls with about the same force that the stylus/record interface generates. It will not show a preferential position on a blank record(yes - I know, friction will be slightly lower on a blank disc vs a modulated disc...). But it will move if you merely breathe in its direction
I've build about a dozen CB and BA arm with a rotating headshell plate that is magnetically centered so it doesn't "wiggle" around as it pleases(so to speak) but will be kept at the correct offset angle when operating without disturbence. The "stiffness" of the magnetic coupling is adjustable, to be set so the fres of the cartridge/headshell plate vis-avis the entire eff. mass of the arm minus said rotating parts is the same as the total arm cartridge resonance frequency in the lateral plane. You now have a damped antiresonator that will "cut" the arm/cartridge resonance frequency in the lateral plane to near immeasurability. More importantly, since all frequencies below 100Hz(and sometimes higher than that) are summed to mono before cutting a record, all low frequency info is strictly equal to lateral displacement. If such low frequency excitement=displacement of the arm occurs, it is the headshell that moves(rotates) laterally, not the stylus, so no signal is generated at/near the lateral fres of such arm. Many detrimental influences on the soundquality of vinyl playback, like stepup transformer saturation, phonostage overload, intermodulation distorsion, woofer "pumping" etc. are greatly diminished. Read: cleaner bass, likely cleaner upper frequency rendering as well.
Many rotating headshell designs are credited with reducing the "pinching effect", see:
Pinch Effect Distortion Calculator - Vinyl Engine
or:
LP distortion mechanisms
So far my findings show a reduction of the pinching distorsions at the price of (frequency-dependent)truncated dynamics unless you place the stylus in the rotation axis of the headshell.
Time for breakfast...
Cheerio,
Frank
Back to topic Carlo, how is your project? WW
Wooden arm done and working, 3d printed waiting the end of my friend's battle against his printer (temperature control fail). I'll post them together someday, hoping to see some new arm realized by others before.
This projects are thought for others, not for me, and I want to be sure that all is ok.
carlo
Wooden arm done and working, 3d printed waiting the end of my friend's battle against his printer (temperature control fail). I'll post them together someday, hoping to see some new arm realized by others before.
This projects are thought for others, not for me, and I want to be sure that all is ok.
carlo
Frank, I didn't mean zero points. What I've meant is presence of lateral forces (and they are substantial) outside of them. As a result, statements of advantages in absence of lateral forces are misleading. Maybe, there are some sonic advantages, and if so, they are out of influence of said forces, as well as of angle errors.
As to you LT arm, I admire that design. As well, as I have no doubt concerning your statements about it.
As to you LT arm, I admire that design. As well, as I have no doubt concerning your statements about it.
Frank,My LT arm will pass the thread test if one pulls with about the same force that the stylus/record interface generates. It will not show a preferential position on a blank record(yes - I know, friction will be slightly lower on a blank disc vs a modulated disc...). But it will move if you merely breathe in its direction
Frank
My string test is a go/no-go test of whether the stylus/groove friction force acting on the geometry of a tonearm results in any side force components i.e., skating. The pass/fail criterion of the string test is independent of how hard you pull on the string. A conventional offset arm can be made to ‘pass’ the string test too, if you pull with the same friction force that the stylus/groove interface generates and the anti-skate setting has been adjusted for that particular stylus/groove friction value. The problem is that stylus/groove friction is not constant. It varies with such factors as record formulation, stylus tip profile, and groove modulation level which changes from point to point in the same record. If a tonearm ‘passes’ the string test for one particular pulling force on the string but not for greater or lesser pulling force, then by definition it fails the string test. As examples for comparison: no matter how hard I pull the string on my servo linear arm it will not skate, no matter how hard super10018 pulls the string on his air-bearing arm it will not skate.
Ray K
Hello Ray,
"The problem is that stylus/groove friction is not constant. It varies with such factors as record formulation, stylus tip profile, and groove modulation level which changes from point to point in the same record. "
Rest assured that I am fully aware of the above. And I also understand your reasoning behind the string test. It simply has no practical meaning for the LT.
Properly set up, I can change VTF with the stylus "riding" on a blank disc and it will remain stationary irrespective of higher or lower VTF(aka more or less resulting friction). A higher tracking force will eventually require resetting overhang(by a tiny margin). Any arm that fails your string test will behave differently...
But none of the above means much if no more arms based on ideas discussed in this thread are being built, so bring them on guys!
Best,
Frank
"The problem is that stylus/groove friction is not constant. It varies with such factors as record formulation, stylus tip profile, and groove modulation level which changes from point to point in the same record. "
Rest assured that I am fully aware of the above. And I also understand your reasoning behind the string test. It simply has no practical meaning for the LT.
Properly set up, I can change VTF with the stylus "riding" on a blank disc and it will remain stationary irrespective of higher or lower VTF(aka more or less resulting friction). A higher tracking force will eventually require resetting overhang(by a tiny margin). Any arm that fails your string test will behave differently...
But none of the above means much if no more arms based on ideas discussed in this thread are being built, so bring them on guys!
Best,
Frank
I wouldn’t say making a tangential pivot arm is a waste of time, but I do think a tangential pivot arm must meet two requirements.
1. Of course, no tacking errors.
2. Free of skating force. Or at least, dramatically reduce skating force.
Otherwise, I simply don’t see any advantages of tangential pivot arms. In my opinion, free of skating force should be the predominant reason to make tangential pivot arms.
1. Of course, no tacking errors.
2. Free of skating force. Or at least, dramatically reduce skating force.
Otherwise, I simply don’t see any advantages of tangential pivot arms. In my opinion, free of skating force should be the predominant reason to make tangential pivot arms.
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Well, I am getting close.
The challenge in building an arm like the Schroder LT, especially for a novice with limited tools/skills, thank God for diyaudio.com, Is mainly getting 4 things correct. The bearing system in the horizontal(low friction), the tracking geometry(complex) and the magnetic force. Everything, table, arm, bearing system, has to be level.
After that the rest of the arm in the vertical plane is more traditional. I will qualify this to say that the vertical bearings have to almost be the equal of the horizontal, very low friction, high quality. It absolutely has to all work together, complimentarily.
So I guess that is 5 things have to be done correctly. Quite a challenge!
I will though have some pics of a, hopefully, working clone arm soon.
I think I will be able to reduce skating forces enough for my needs.
The challenge in building an arm like the Schroder LT, especially for a novice with limited tools/skills, thank God for diyaudio.com, Is mainly getting 4 things correct. The bearing system in the horizontal(low friction), the tracking geometry(complex) and the magnetic force. Everything, table, arm, bearing system, has to be level.
After that the rest of the arm in the vertical plane is more traditional. I will qualify this to say that the vertical bearings have to almost be the equal of the horizontal, very low friction, high quality. It absolutely has to all work together, complimentarily.
So I guess that is 5 things have to be done correctly. Quite a challenge!
I will though have some pics of a, hopefully, working clone arm soon.
I think I will be able to reduce skating forces enough for my needs.
1. Is easy to fulfill with clever design like that of nocdpls
2. This can be fulfilled only if the pivot is always in line with the tangent of the actual groove. A fixed pivot will not fulfill this condition, period.
I have an idea to possibly clear up any ambiguity wrt out of groove skate force testing.
A blank LP either chemically etched with a pattern corresponding to a 1khz mono signal, or a metal plate etched the same to press a blank LP.
It appears from investigations that you could etch any signal you could possibly need (in metal, so far).
Any critique why this won't work?
A blank LP either chemically etched with a pattern corresponding to a 1khz mono signal, or a metal plate etched the same to press a blank LP.
It appears from investigations that you could etch any signal you could possibly need (in metal, so far).
Any critique why this won't work?
This can be fulfilled only if the pivot is always in line with the tangent of the actual groove.
A fixed pivot will not fulfill this condition, period.
True the first, doubts for the second. That's why i tried the way of a true Thales.
Even if the Syrinx didn't work i'm still convinced that only an extensible arm (a cathetus, not a radius) follows this condition; we have "only" to find the way of driving it correctly.
In the case of Birch or similar based arms the pivots are evidently not in line. But, which one is the pivot, and when?
Have you examined my confused effort of vectors breakdown for the Rabbit tonearm, lcsaszaar? there are many things that need an expert's explanation.
carlo
thanks for "clever design": not so easy to find, at least for me
A fixed pivot will not fulfill this condition, period.
True the first, doubts for the second. That's why i tried the way of a true Thales.
Even if the Syrinx didn't work i'm still convinced that only an extensible arm (a cathetus, not a radius) follows this condition; we have "only" to find the way of driving it correctly.
In the case of Birch or similar based arms the pivots are evidently not in line. But, which one is the pivot, and when?
Have you examined my confused effort of vectors breakdown for the Rabbit tonearm, lcsaszaar? there are many things that need an expert's explanation.
carlo
thanks for "clever design": not so easy to find, at least for me