Hi, Yesterday I got my SP10 finally going & mounted a SPU GE set at -8.5mm Under-Hang on the 12'' Temaad arm I have.
Holy S**T, talk about dynamic impact of a system, I was amazed at the the grip on preceding's. This table managed to out class anything I had ever used before. The sound from what is supposedly lowly MC cart really sung out in Under-Hang. With the bass & sound staging being particularly impressive.
Cheers
Holy S**T, talk about dynamic impact of a system, I was amazed at the the grip on preceding's. This table managed to out class anything I had ever used before. The sound from what is supposedly lowly MC cart really sung out in Under-Hang. With the bass & sound staging being particularly impressive.
Cheers
As usual the Guardians of the Known Audio Universe have it wrong.
I have been curious about this for years and finally got the nerve to convert my SUPATRAC arm to underhung.
I used the inner grooves grid of the Allen Wright protractor to adjust tracking.
Set my tracking weight - even with only one screw holding the cartridge it was as good as I have ever heard and seemed to be better which will require more hours to be able to say with surety. Using a Transfiguration Proteus and Channel D LINO.
As usual - when one is afraid to try something you never learn much of anything.
One wonders if the SUPATRAC's horizontal unipivot is especially good at this.
But this is only for those who listen to their systems and not write about them.
I have been curious about this for years and finally got the nerve to convert my SUPATRAC arm to underhung.
I used the inner grooves grid of the Allen Wright protractor to adjust tracking.
Set my tracking weight - even with only one screw holding the cartridge it was as good as I have ever heard and seemed to be better which will require more hours to be able to say with surety. Using a Transfiguration Proteus and Channel D LINO.
As usual - when one is afraid to try something you never learn much of anything.
One wonders if the SUPATRAC's horizontal unipivot is especially good at this.
But this is only for those who listen to their systems and not write about them.
I too am a recent convert.
Adapted a wand to underhung on my Supatrac clone, and used DNic's protractor & calculations (thanks!) The slam on the Supatrac was amazing in offset mode, but now its like on steroids.
I have retained the antibias though, as there was quite a skew on the cantilever the first half of the record. Rights itself midway, but I find with my variable antibias mech, there is no skew all the way through the record.
I have returned to offset several times during testing, but can't unhear the underhung. I dont think I will go back......
Adapted a wand to underhung on my Supatrac clone, and used DNic's protractor & calculations (thanks!) The slam on the Supatrac was amazing in offset mode, but now its like on steroids.
I have retained the antibias though, as there was quite a skew on the cantilever the first half of the record. Rights itself midway, but I find with my variable antibias mech, there is no skew all the way through the record.
I have returned to offset several times during testing, but can't unhear the underhung. I dont think I will go back......
I am glad you tried it. The trick is how long you can enjoy it.
As you know I was a very excited about this but after a a few weeks of listening it was driving me crazy. I thought the thread was over so i never posted my eventual disappointment.
My motivation was the minimizing the need of anti-skate correction - I could not get my SUPATRAC (not a clone) anti-skating to be linear. I suspect you will find the same thing with your clone - the arm naturally comes to rest in the middle of an LP. So the beginning of the record needs lots of attention and the second half has natural anti-skate. Thanks to WALLY SKATER to show me clearly what was going on with the arm.
I made a magnetic anti-skate that has a string to pull the arm the needed amount for the fist half of the record and a second string to stop that for the second half of the record. A balancing act but not that hard to implement if you have the room around the arm and turntable. A push-pull arrangement.
After doing this I find the arm sounds much more relaxed and correct with the standard alignments.
Enjoy it as long as you can. As someone elsewhere wrote when reviewing the arm I always mis-name as VIVID - I can never remember the name - but he called it a wild roller coaster ride - and that is true. It was exhilarating but ultimately exhausting.
As you know I was a very excited about this but after a a few weeks of listening it was driving me crazy. I thought the thread was over so i never posted my eventual disappointment.
My motivation was the minimizing the need of anti-skate correction - I could not get my SUPATRAC (not a clone) anti-skating to be linear. I suspect you will find the same thing with your clone - the arm naturally comes to rest in the middle of an LP. So the beginning of the record needs lots of attention and the second half has natural anti-skate. Thanks to WALLY SKATER to show me clearly what was going on with the arm.
I made a magnetic anti-skate that has a string to pull the arm the needed amount for the fist half of the record and a second string to stop that for the second half of the record. A balancing act but not that hard to implement if you have the room around the arm and turntable. A push-pull arrangement.
After doing this I find the arm sounds much more relaxed and correct with the standard alignments.
Enjoy it as long as you can. As someone elsewhere wrote when reviewing the arm I always mis-name as VIVID - I can never remember the name - but he called it a wild roller coaster ride - and that is true. It was exhilarating but ultimately exhausting.
Hi,
Time will tell if it is just a temporary fashion of the moment, as many others in the past, or it will be a new course in HIFI.
If it is the a new course in HIFI tangent TA shall face some competition from these TA/HU settings.
Later on I shall also test the HU vs my tangent LT clone.
Rgds
Adelmo
Time will tell if it is just a temporary fashion of the moment, as many others in the past, or it will be a new course in HIFI.
If it is the a new course in HIFI tangent TA shall face some competition from these TA/HU settings.
Later on I shall also test the HU vs my tangent LT clone.
Rgds
Adelmo
There is nothing wrong with the SUPATRAC - it is simply a function of how the arm is suspended with the hoists to get it to contact the pivot. I cannot think of any way to not have the centering bias. Thinking of caster adjustment for automobile steering linkages - maybe if the hoists were more straight than at an angle? Just a thought - is the angle magnifying the centering effect?
The problem is getting a standard type of anti-skate to turn off at the midpoint and I cannot figure out a way to do that.
I will take a picture of it - most people would not put up with this.
So there is no misunderstanding - I think the arm is a great design and had (the price is creeping upwards) a price not in keeping with its performance. The way it delivers dynamic information is the best I have ever had and that only means so much. I am not an equipment trader.
I was swayed by the idea of the arm and the fact that Richard Braine had put in lots of thought and elbow grease in designing it.
I cannot think of any component that cannot be improved with some respectful tinkering.
Adelmo,
I do not think of it as fashion. I approached it hoping it would solve a problem.
I hope you continue to enjoy it. There is always the aspect of my implementation not being as good as it should have been.
I tried no overhang and adjusting the cartridge to have some angle - this was also interesting - most of the life of underhung but less of what ended up driving me crazy.
But I still am preferring the old tried and true but I miss that excitement.
The problem is getting a standard type of anti-skate to turn off at the midpoint and I cannot figure out a way to do that.
I will take a picture of it - most people would not put up with this.
So there is no misunderstanding - I think the arm is a great design and had (the price is creeping upwards) a price not in keeping with its performance. The way it delivers dynamic information is the best I have ever had and that only means so much. I am not an equipment trader.
I was swayed by the idea of the arm and the fact that Richard Braine had put in lots of thought and elbow grease in designing it.
I cannot think of any component that cannot be improved with some respectful tinkering.
Adelmo,
I do not think of it as fashion. I approached it hoping it would solve a problem.
I hope you continue to enjoy it. There is always the aspect of my implementation not being as good as it should have been.
I tried no overhang and adjusting the cartridge to have some angle - this was also interesting - most of the life of underhung but less of what ended up driving me crazy.
But I still am preferring the old tried and true but I miss that excitement.
The two cents no one asked for. I bought a test record and did several measurements with my turntable last summer looking to optimize playback before ripping some vintage albums to digital. After studying the static force balance on a stylus I concluded that any anti-skate force applied to the tone arm must be balanced by an equal and opposite force through the suspension of the stylus, pushing it off center. Of course there are dynamic forces from record eccentricity, vertical record warp and the audio signal, that are being ignored. Without an anti-skate force applied to the tone arm all of the "static" forces would sum to zero at the stylus sides with any imbalance occurring at the interface with the groove walls. It just makes sense to me that the sum of static forces at the cartridge body is zero, so the skate force must come up through the stylus suspension where it is opposed by the anti-skate force coupled to the cartridge by the tone arm. So the anti-skate force works against the stylus compliance to create a horizontal offset of the stylus. Having the stylus suspension off center due to these forces didn't seem so good to me, so I sold that pivot arm table and bought two linear tracking tables. When properly aligned these track perpendicular to the groove and see no appreciable static tracking side force. Feel free to start the chorus of "boo and hiss". I believe I have described the physics correctly. Equal an opposite forces. The only way I've seen to eliminate the skate force, and the associated stylus groove sidewall force imbalance, is to keep the line between the stylus to tone arm pivot point tangential to the groove. Have fun out there.
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@olsond3
Hallelujah!
You are spot on with your observations, your analysis and understanding of physics, and your conclusions.
I am in total agreement with you, and implemented the same solution for myself over 40 years ago.
I'm starting a chorus of "hurras!", let's see who wins. 👍
Ray K
Hallelujah!
You are spot on with your observations, your analysis and understanding of physics, and your conclusions.
I am in total agreement with you, and implemented the same solution for myself over 40 years ago.
I'm starting a chorus of "hurras!", let's see who wins. 👍
Ray K
HI,
I enjoy DIY TA, though I have in general, a very small experience in TAs. In fact besides my clones for the commercial TA I used only the TP16, Rega RB 250, Jelco SA 750 L 12 inch.
The term fashion I meant was for the under hung settings, not to the TA technology.
Regarding :
The problem is getting a standard type of anti-skate to turn off at the midpoint and I cannot figure out a way to do that.
I think It is possible to be made and I think is not complex as well. I did a kind of it for my first Supatrac clone.
Best regards
Adelmo
P.S. Sorry when I wrote it I did not see the AS video from VIC. Mine was a bit different, but results similar.
RGDS
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Oslond....I get the gist of what you are saying, but with decades experience of air bearing Linear Trackers, they are often criticised for the large lateral inertia (a positive according to Ladergaard). You could say the stylus is constantly stressed pulling the weight along the groove, to & fro, especially bad with eccentric records, which most of them are. There is also the issue of horizontal level, which has to be perfect to balance the sideways tracking forces, and impossible to equalise with dished platters or warped records.
I got into pivot arms again after reading about the SupaTrac. So I built a clone and have not looked back. Understanding the planted pivot point & rigidity principle on which Richard Braine's design is built, it sonically totally trounces my air arms which I now realise are flawed from the start (as are most tonearms) lacking rigidity at a microscopic level. Pivot arms are also a lot more fun to play with trying different geometries, under/over hung etc. Bias is a challenge, but LT's aren't perfect either. Its all a compromise!
I got into pivot arms again after reading about the SupaTrac. So I built a clone and have not looked back. Understanding the planted pivot point & rigidity principle on which Richard Braine's design is built, it sonically totally trounces my air arms which I now realise are flawed from the start (as are most tonearms) lacking rigidity at a microscopic level. Pivot arms are also a lot more fun to play with trying different geometries, under/over hung etc. Bias is a challenge, but LT's aren't perfect either. Its all a compromise!
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k9vap - your antiskate is turned off for the run out - hardly useful - but then maybe your arm does not behave the same way as Braine's. Maybe your hoists are allowing a more neutral bias? I cannot see your hoist arrangement. I looked at the early pictures and it looks to me your hoist arrangement has similar angles to Braine's.
With mine - the anti-skate should be turned off after the middle of the record if anti-skate is set for the first half of the record.
It is easy to replicate what the WALLY TRACKER does - Pete Riggle described the solution years before the WALLY TRACKER came to market. I got the WALLY TRACKER because I figured it would be more repeatable. See here: http://www.vtaf.com/anti-skate-considerations.html#/
See how your arm behaves across the record. It was enlightening for me. Your anti-skate works basically as Braine's implementation so when set to get it right for the first half it has too much for the second half due to the arms natural tendency to return to the center of the LP. Which offers a good value of anti-skate for a 2 grams tracking weight with no bias at all but now you have pro-skate for the first half of the LP.
No question - if one cannot stand to compromise audio tinkering will bring one nothing but misery. Finding the clever compromise is the key. And that seems to to take a lifetime.
With mine - the anti-skate should be turned off after the middle of the record if anti-skate is set for the first half of the record.
It is easy to replicate what the WALLY TRACKER does - Pete Riggle described the solution years before the WALLY TRACKER came to market. I got the WALLY TRACKER because I figured it would be more repeatable. See here: http://www.vtaf.com/anti-skate-considerations.html#/
See how your arm behaves across the record. It was enlightening for me. Your anti-skate works basically as Braine's implementation so when set to get it right for the first half it has too much for the second half due to the arms natural tendency to return to the center of the LP. Which offers a good value of anti-skate for a 2 grams tracking weight with no bias at all but now you have pro-skate for the first half of the LP.
No question - if one cannot stand to compromise audio tinkering will bring one nothing but misery. Finding the clever compromise is the key. And that seems to to take a lifetime.
I always thought those air bearing tone arms looked interesting. I have not used one.
I have two of the more common linear tracking designs, where the base of a pivoting tone arm rides on a motorized trolley. ReVox 790 and a Techniques SL-Q5. Optical sensors measure the tone arm angle and a servo drive slowly and steadily moves the base along to keep the average angle zero. These have small tone arms with low inertia relative to a typical long tone arm. When the servo control loop is properly tuned and the mechanism is highly damped, the slow often continuous horizontal motion of the tone arm produces no audible signal. As the motion is horizontal it would appear as monaural bass possibly at the tone arm resonance which is tuned to be removed by a typical rumble filter. Typical record eccentricity will produce more measurable output than the servo drive. After re-assembly while repairing one of my tables the servo gain was way out of bounds and it would move the tone arm base in pulses about once a second. A pulse of motion would excite the horizontal tone arm / stylus compliance resonance for a few cycles.
The picture below shows a graph of stylus displacement while playing a track on the Ortofon test record. The 10 Hz horizontal resonance of the tone arm was excited by the pulse on the servo motor producing the out of phase waveforms from the two channels. This was playing a 1 kHz 5 cm/s tone in one channel from a test record. After properly tuning the feedback these pulses were not detectable against the background of the normal tone arm motion.
These designs require a control system engineer to design them, so boutique manufacturers can't afford to keep one of those just sitting around. Just like a CD player, they don't appeal to the audiophile dealers, as they can't produce a revenue stream selling you new tone arms and other doo dads to swap out in these machines as changes would screw up the servo drive.
Oslond
Cant comment on servo arms, never owned one. My point was playing vinyl by whatever means is always a compromise. At the moment I am just exploring, learning & having fun...........
Rick
After observing my video I realised someone would pick that up. I was using Norwegian Mood, Side one, to test skate behaviour at runnout (which only has 2 tracks on it) so the runout groove actually starts at the null point. Shudda changed record for video to avoid confusion in hindsight.
I am running an underhung arm at the moment, so the 'null' point on the arm is just over half way (10-11cm from spindle center). There is a torsion effect from the Supatrac string so you can counteract this to a certain extent depending on where you position the pivot, but I set it to match the underhang null point. So my arm behaves as a typical underhung arm.....inwards skating force, then outwards.
Observing the skew of the stylus while playing a record (no bias) the start of the records causes a severe inward pull, so the skew is toward the outer track, and this skew persists, but lessens, until the null point, where it totally centralises. After the null point, I can see no skewing, so assume the force outwards is of a much lower magnitude than the force inwards. I figured an easy mod to my anti-skate device to counteract the inward force, and gradually reduce as it approaches the null point, then stop. By adjusting the counterweight I can control this force so the stylus remains more or less centered thoughout its travel.....at least to the naked eye.
I am now working on a new underhung arm with a heightened hoist and decreased width between string holes on the thrustbox. I am thinking increasing height between hoist & pivot will lessen and reduce string angle from hoist to string holes will reduce torsion effect and therefore force on stylus. To me its worth pursuing as it sounds so damn good!
Cheers
Vic
Cant comment on servo arms, never owned one. My point was playing vinyl by whatever means is always a compromise. At the moment I am just exploring, learning & having fun...........
Rick
After observing my video I realised someone would pick that up. I was using Norwegian Mood, Side one, to test skate behaviour at runnout (which only has 2 tracks on it) so the runout groove actually starts at the null point. Shudda changed record for video to avoid confusion in hindsight.
I am running an underhung arm at the moment, so the 'null' point on the arm is just over half way (10-11cm from spindle center). There is a torsion effect from the Supatrac string so you can counteract this to a certain extent depending on where you position the pivot, but I set it to match the underhang null point. So my arm behaves as a typical underhung arm.....inwards skating force, then outwards.
Observing the skew of the stylus while playing a record (no bias) the start of the records causes a severe inward pull, so the skew is toward the outer track, and this skew persists, but lessens, until the null point, where it totally centralises. After the null point, I can see no skewing, so assume the force outwards is of a much lower magnitude than the force inwards. I figured an easy mod to my anti-skate device to counteract the inward force, and gradually reduce as it approaches the null point, then stop. By adjusting the counterweight I can control this force so the stylus remains more or less centered thoughout its travel.....at least to the naked eye.
I am now working on a new underhung arm with a heightened hoist and decreased width between string holes on the thrustbox. I am thinking increasing height between hoist & pivot will lessen and reduce string angle from hoist to string holes will reduce torsion effect and therefore force on stylus. To me its worth pursuing as it sounds so damn good!
Cheers
Vic
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What if the center of the pivot was moved to the end of the playing area instead of the null. This would eliminate the need for the skate reversal. Or will this twist the azimuth also?
HI Vic,
Have you considered to use a very tiny bearing with the shaft hole 1 or max 2mm to be used as hoist turning point of the threads?
Not sure it is working, in the past I did try a different type of rotation hoist point but did not work. The one above I think may work, just more complex to be made but might improve the skating issue you are facing now with HU test.
I wanted to try it, but later on I did focus on the LT TA.
RGDS
Adelmo
Vic,
That did confuse me.
I congratulate you on making that work! There is no question your solution is far more sophisticated than the BLACKBIRD's. I do not see how one could do that with the standard arm - just not enough room. I see evidence of much trial and error in coming up with that now that I better understand what you did.
There is no question Braine's idea is first class and even with no bias the arm sounds good - but it does tend to twist cantilevers when left that way. No question it sounds much better with bias - maybe we should call it tempered bias in this case?
I think he should ask you for a consultation.
I will look forward to your new arm - I have no idea if this is the answer to the question but I do know this is one of those things that will never be answered without a trial and I admire your abilities to find this out.
Still think all interested in anti-skate should investigate the WALLY TRACKER or Pete Riggle's DIY structure to see this at work. I am impressed you got this without this tool. All the more impressive are your observational skills. Wish I could say the same for myself. I never got it until I used the WALLY TRACKER. Not to say the WALLY TRACKER is the end of the search - one still has to interpret what it is telling you and how to use that information.
Many of the WALLY tools I think are somewhat silly - I am not a devotee by any means - but his video of the skating propensities of various cartridge angles did make me think that the initial explanation of why straight arms were better was wrong and that all arms need anti-skate and your arm recognizes this. I will probably have to try this again.
Your efforts are important. Thanks for your work.
That did confuse me.
I congratulate you on making that work! There is no question your solution is far more sophisticated than the BLACKBIRD's. I do not see how one could do that with the standard arm - just not enough room. I see evidence of much trial and error in coming up with that now that I better understand what you did.
There is no question Braine's idea is first class and even with no bias the arm sounds good - but it does tend to twist cantilevers when left that way. No question it sounds much better with bias - maybe we should call it tempered bias in this case?
I think he should ask you for a consultation.
I will look forward to your new arm - I have no idea if this is the answer to the question but I do know this is one of those things that will never be answered without a trial and I admire your abilities to find this out.
Still think all interested in anti-skate should investigate the WALLY TRACKER or Pete Riggle's DIY structure to see this at work. I am impressed you got this without this tool. All the more impressive are your observational skills. Wish I could say the same for myself. I never got it until I used the WALLY TRACKER. Not to say the WALLY TRACKER is the end of the search - one still has to interpret what it is telling you and how to use that information.
Many of the WALLY tools I think are somewhat silly - I am not a devotee by any means - but his video of the skating propensities of various cartridge angles did make me think that the initial explanation of why straight arms were better was wrong and that all arms need anti-skate and your arm recognizes this. I will probably have to try this again.
Your efforts are important. Thanks for your work.
Guys
Finally got this arm working. Thing with Supatrac is all the settings have to come together at the same time.
Made a totally new arm dedicated to underhung/Supatrac and replaced with the thrustbox and with an L-plate. Main issue, as we know, is null point half way across the record from the underhang, which is fighting the torsional forces of the string suspension.
As Rick suggested, I tried moving the pivot to overide the underhang null point trying to get it to behave like a normal offset arm. Even the setup I had before using the antiskate only half way need the pivot to be at an extreme which made parking the arm unstable.
My lastest idea was to tension the string with a clockwise twist. I was shocked that a single twist worked! The arm now has a tendancy to skate inwards, like a regular arm. It was easy to apply a counter-force which worked all through the arm travel. The pivot is in the correct position, and the arm parks easy. Early days, but looks promising!
Finally got this arm working. Thing with Supatrac is all the settings have to come together at the same time.
Made a totally new arm dedicated to underhung/Supatrac and replaced with the thrustbox and with an L-plate. Main issue, as we know, is null point half way across the record from the underhang, which is fighting the torsional forces of the string suspension.
As Rick suggested, I tried moving the pivot to overide the underhang null point trying to get it to behave like a normal offset arm. Even the setup I had before using the antiskate only half way need the pivot to be at an extreme which made parking the arm unstable.
My lastest idea was to tension the string with a clockwise twist. I was shocked that a single twist worked! The arm now has a tendancy to skate inwards, like a regular arm. It was easy to apply a counter-force which worked all through the arm travel. The pivot is in the correct position, and the arm parks easy. Early days, but looks promising!
Adelmo
Not sure that would make much difference. The string torsion in the Supatrac is annoying.....but actually increasing the tension with a twist gave me a reliable continuous force I could counter with a normal antiskate. It overrides the underhung null, so no longer an issue.....or we will see.
Cheers
Vic