HELP - tonearm with no offset, overhang or side thrust.

[Adelmo]

I have ordered a WALLY SKATER - at least I will have a better idea of that is happening in my situation.

Despise is too strong a word - I do not despise the person just the lack of curiosity and I should have made that clear.  All the while acknowledging that if one is happy with their system - that is a good thing but something I have never experienced for long!  There is always something bothering me and that must be investigated, for better and for worse, I must admit.

Since I wrote this I have been going back and forth between the standard Stevenson alignment and a ZERO overhang kludge where I use the inner most grid on the Hoffman protractor to set the angle in the tonearm.

I have been going back and forth and find myself enjoying the wacky zero overhang the best.  You get most of the excitement that underhung brought with none of the abrasiveness.

One does wonder, based on the old saw about perfection being the enemy of the good - that the classical two point idea has theoretical correctness but many times we find that is not as close to perfect as we would wish or the promised perfection is not realizable in the real world.  LP playback retains much mystery - one wonders if anti-skate is the biggest problem with LP playback?  Could the zero overhang approach allow a set amount of anti-skate to average best across the side?  I also tried a anti-skate scheme where I was pulling the arm from both sides and trying to use this to vary the force across the record.  So far, it has turned out to offer nothing of use.  When the WALLY SKATER comes I will be able to get a better idea if this has any use at all.

I hear a slight softening of the highest frequencies I can hear compared to Stevenson - for these comments I am speaking of what I hear in the region where Stevenson has its claim to superiority.  I hear nothing in the first half of the record that sounds wrong in comparison.

I am as mystified by all of this as anyone.

Maybe when I get my WALLY SKATER I can see the errors of my setup and all of this can be cast aside!

What is interesting - working with one's tonearm, even on a futile endeavour, usually leads to learning something useful.  This has been the case for me.  A good excuse to learn the SUPATRAC much better than I had before.

Hi,

Recently I am using a clone of the LT TA on my floating TT. Though the Mag Floating is not soft as other TT such as Thorens, LInn..... it has some micro floating anyhow. This change the platter level and TA level therefore change the skating force of the TA.

I have to say that as far the TA is tracking the LP, despite there is a variation of the skating, the sound do not get worse as was supposed to be. My simple conclusion is that the benefit of the LTTA ( zero over hang and zero off set of the cart and Tangent 90 degree ) is the main improvement even when tracking the last song nearest the LP label.

I am using heavy TA, standard Denon DL 103, TVF set at 2.6Gr.

Even I use a Pre Phono ( Aria first version ) with MC setting and no SUT, it sounds very good to my hears.

I also had a clone of the Supatrac TA, sounded good but I like more this one. Suoatrac TA needed a very well tuned up any skating, not easy to have it set well for all the record. However the dimension of the Supatrac clone 12 inch were:

Over hang 15mm
Distance spindle to TA rotation point 290mm
Were the same dimension of the Jelco SA 750 L and I sold it as my clone sounded better.

Interesting the Wally device results of yours.

Thank you and best regards.

Adelmo

[low pitch]

It's not too hard to set up a wally whatsit and use Lami's Theorem as per link below:
https://www.lencoheaven.net/forum/index.php?topic=42326.msg513578;topicseen#msg513578

I'll have to look back at my notes for details.

[tabarddn]

Hi Guys, Not sure why we are talking about Wally's items on this thread. As one of the major points of U/H is that do not use Anti-skating. Anyone using anti-skating with U/H is defeating it's purpose.!!

Cheers Derek

[flood2]

Hi Guys, Not sure why we are talking about Wally's items on this thread. As one of the major points of U/H is that do not use Anti-skating. Anyone using anti-skating with U/H is defeating it's purpose.!!

Cheers Derek

If you'd read all the comments carefully, then you will recall that Rick had ultimately rejected the underhang concept but had been testing a Supatrac in this mode. I pointed out that the Supatrac hoists introduce a bias and therefore part of his disappointment was very possibly because of the hoist bias which could be both additive and subtractive to the inherent skating force vector associated with a pivoted arm and that in fact he might consider re-doing the experiment with one of your arms in order to try to reproduce what you claim to hear. His motivation for trying underhang was based on your claim that no antiskate was needed so I pointed out that it was possible to calibrate his antiskate AND enjoy the benefits of low tracking distortion. That evidently appealed to him.

[flood2]

It's not too hard to set up a wally whatsit and use Lami's Theorem as per link below:
https://www.lencoheaven.net/forum/index.php?topic=42326.msg513578;topicseen#msg513578

I'll have to look back at my notes for details.

Martin,
The Wallyskater is all about convenience - the device has calibration marks so it is easy to get reasonable consistency and properly calibrate the antiskate dial/mechanism on any turntable and compare the actual effect on the inner and outer grooves with better repeatability.
Most spring based antiskate mechanisms show considerable variation between inner and outer grooves and very often the scale printed out the antiskate dials are way off what is actually being applied to the tonearm so it is no wonder people are often frustrated enough with the sound to want to explore alternatives like an underhung arm.

The sensible way for answering the question about whether tracking error really matters (compared to other sources of distortion) is to compare the result of a properly biased overhung tonearm that has been accurately aligned. Most people get nowhere close to achieving this condition because they make many assumptions; firstly that the tools they use are accurate in the first place, that the tonearm manufacturer has properly calibrated the antiskate and that it doesn't vary in bias significantly between inner and outer grooves, that the user can actually achieve the required accuracy in alignment and that all variables have been optimised. The probability that all variables are spot on is very low which is why this thread exists!
The skating force curve follows a similar trend to the tracking error variation with the highest magnitude at the outer edge and inner radius. Minimizing the tracking error will minimize the variation of the skating force so that a constant bias force can be determined that gives perfect compensation at two points on the skating force curve. The challenge is to find the mean value that minimizes the deviation from the correct bias value. The spring mechanisms that I have analysed give a higher bias on the inner grooves than at outer grooves. This is not necessarily a bad thing if the gradient of the force vs groove radius results in an acceptable linear approximation to the skating force curve which then provides  good compensation for over 2/3 of the envelope. One would set a reference value somewhere within the envelope between the outer null and minimum groove so that as the bias increases, it approximates the skating force curve and still gives up to two points of correct bias.
What my experiments have shown is that fairly large errors in antiskate can be tolerated at the outer grooves (similar to tracking error), but the bias needs to be correct on the inner grooves since the cantilever deflection resulting from errors in the applied torque cause considerable audible distortion both due to the induced tracking error and the mistracking that can occur as the signal level increases. So as long as the applied bias reasonably approximates the curve with minimized variation (which also requires accurate alignment), you should be able to have your cake and eat it without sacrificing one parameter to improve another.

Derek,
If underhang really does have an advantage, then the benefits should be universally appreciated on any tonearm bearing design and to survive the comparison when a properly calibrated overhung alignment is used in comparison so you shouldn't be concerned about the discussion around the Wallyskater. It is simply a tool that will help to answer which of skating force and tracking error has greater importance. At present, no one has been able to adequately reproduce what you hear and that is because of the inevitable variation in set up and alignment techniques as well as the peculiarities of particular tonearm designs such as the Supatrac. Much of what you have claimed cannot be verified as you haven't provided sound clips and so we rely entirely on your opinion but this is not really sufficient to objectively prove your assertion.