Stylus force digital scales

People think that it's better quality if it's more expensive, which is not the case. Look, I gave $ 25 on this Vont digital scale, which I've had for 2 years. Reasonable price and quality have been proven over time. To this day, I haven't had any technical defects with it; I just change the batteries monthly. The whole family uses this scale, and we are 4 users. My husband also bought one for the gym where he works; he is a fitness trainer. I like that it measures all the results in one app to see your success in a while.

Good olde 2013.

@timathy - that was back in 2013 when things were much cheaper!

Wait, wait, wait, Amazon has them for only 20 bucks? Are you serious? Dude, I mean, that's an insane difference, and I don't understand it. Why do we have to pay 200-300 dollars for it, while some companies get it for ten times less? Man, that's not even serious. I won't buy any products from this company from now on. I found a genuinely fantastic scale on Amazon. Check this out https://www.amazon.com/Vont-Smart-Body-Scale-Black/dp/B08XYX8RDR/. I think it's totally worth it. But it's out of stock right now.

@brf you are totally right. I was thinking about this more during a drive right after I posted, and never corrected. Good stuff.

@lewm I’d not expect their to be any noticeable attraction (we’re talking about .1g of effect which I’m sure you could not feel)

the test id like to run (which I will when I get home) is to load the platform statically with something non magnetic and then bring a magnet close to the scale and see if the weight reading changes I.e. if the magnetic field has an effect on the weighing mechanism itself.  I’ll report back on what I find out

All physically true, but, does it matter? The optimal VTF for any given cartridge is an unknown

I agree, I only use the stylus force gauge to set the vtf at the manufacture's recommended force and then perform fine adjustments by ear.  Personally, I don't need a scale that measures to the 1,000 of a gram.

All physically true, but, does it matter? The optimal VTF for any given cartridge is an unknown. We could try to measure by incremental adjustments while taking measurements, but the results would always be a range that is dependent on the accuracy and precision of our measuring devices. Plus the recording being played will also determine the outcome and define the parameters and conditions under which the analysis was performed i.e., the so-called asterisk in the footnote. So, the optimal VTF will always be a range, it can't be anything other than that, and, as long as we are in that range, slight variations of up and down motion on the cartridge imparted by the record and that change the VTF ever so slightly as described above simply          won’t          matter.

Lewm, I believe we are saying the same thing if I replace force of gravity "on an abject" with force vector. An object perpendicular to the earth’ surface will experience only one force vector. Anything other than perpendicular, results in more than one force vector and that is (as you obviously know) why balls roll downhill and objects topple if not supported. Thanks for the additional clarification.

Folkfreak,  I took a powerful magnet to the weigh pan of my digital VTF scale, and there was zero attraction of the magnet to the weigh pan or even to the body of the scale itself.  Seems that even though your plastic-bodied scale and my metal-bodied scale look alike (maybe exactly alike), there actually was a good reason why mine cost more money, other than the metal outer shell. For once in my life, my extravagance paid off.

nrenter and brf, You both got it right for the wrong reasons.  My physics professor in college would have given you both an "F", but he was mean.  The force of gravity never changes.  What changes is the magnitude of the force vector in the vertical direction, when you rotate the tonearm in a vertical arc away from or down towards the LP surface.  The magnitude of the vertical force vector due to gravity changes because you are shifting the center of mass toward the pivot (if you raise the tonearm) or away from the pivot (if the arm wand moves toward the LP surface).  It's like a seesaw. When you raise the tonearm, some of its mass is shifted toward the pivot and thus the pull of gravity on the cartridge is partly borne by the pivot, not the cantilever, during that moment.  

@nrenter wrote The only change in the vertical force vector is as the stylus is raised vertically is due to the change in gravitational force as you move [mm to cm] further away from the center of gravity, and therefore the force of gravity changes. This is why it's called "Vertical" tracking force - vertical states the direction of the force vector.

This statement is incorrect and you gave the reason in the body of your response. The force of gravity is at its greatest when perpendicular to the earth's surface (you call it vertical).  With a pivoted tonearm, the cartridge travels in an arc and within that arc, there can only be one position in which the stylus tip is perpendicular to the playing surface and it is in this position in which the force of gravity is at it's maximum.  Any deviation from perpendicular will result in a less gravitational force. 

This is the same rationale as why weigh scales must be place on a flat surface to read accurately, otherwise the weight will not be transferred perpendicular to the earth's surface.

VTF only changes when you hit a warp because of inertia - the same reason you feel more force (and then less force) when driving over a bump in the road. It has nothing to do with the angle of the tonearm. The only change in the vertical force vector is as the stylus is raised vertically is due to the change in gravitational force as you move [mm to cm] further away from the center of gravity, and therefore the force of gravity changes. This is why it's called "Vertical" tracking force - vertical states the direction of the force vector.

The very expensive Rega scale does its job nicely and quickly. It always tares itself before weighting. The weight pan is a little dish so the actual measurement level is very close to record´s surface. Highly recommended for all vinyl lovers. Many thanks Folkfreak :)

@lewm it may not be an issue of interaction with the pan but an effect upon the mechanism itself, I guess you might know by seeing if bringing the cartridge close to a previously loaded pan reduced the measured weight?

folkfreak, That's very interesting and a bit disconcerting.  Steel can contain some low concentration of iron, so that may be the problem. I will check the weigh pan of my digital scale with an actual magnet, to see if the magnet "likes" the weigh pan at all.  FWIW, the weigh pan on my digital scale is white-ish in color and looks like it may be ceramic, not metal at all, which I hope is the case.

@lewm as I said in my last post my experience is that even scales with non magnetic pans suffer from magnetic interactions. I own several scales with such pans and all read differently than my all plastic options (cartridge man and rega) - and all read exactly the same with reference weights (which are not magnetic)

cleeds,
Let's agree to disagree, once you have acknowledged the following:
(1) Our disagreement is NOT about the degree of difference in VTF caused by a warp or whatever.  I have written twice already that I agree the difference is "small" (if we're talking about LP thicknesses).  I thought we were arguing over your statement in response to someone else, to the effect that VTF would not change AT ALL when the stylus traverses a warp, because (you said) gravity is a constant, etc.  I of course agree that gravity is a constant, but you failed to take into account that raising the tonearm up above the horizontal, as happens when playing a warp, does change VTF, because it changes the geometry and introduces a force vector that is not directed downward, perpendicular to the LP surface.  That small force vector subtracts from the effect of gravity to pull the cartridge down on the LP, reducing the effective VTF.  And talk to Einstein or any other theoretical physicist, if you cannot abide thought experiments.  Based on the limits you want to set on logical arguments, we would still believe in a flat earth.

I notice now that you have changed your tune; you now say that the "thickness of an LP" has a "trivial" effect on VTF.  At least you agree that a thick vs thin LP or a warp would have SOME effect on VTF.  And I am telling you why it would.

(2) The bit about Dynamic VTF. You are confusing me with someone else (whom I respect) who commented that tonearms with dynamic VTF would be less subject to variation in VTF on warped LPs.  In fact, I think you're misquoting him, but go argue with that guy.

lewm

You don’t understand. And you don’t want to understand. So why bother? ... Or simply do the experiment I suggested: Measure or set VTF with the tonearm parallel to the surface of an LP. Then place a couple of spacers under your digital scale ... measure VTF again ... Don’t come back at me until you’ve done this ...

Pardon me, but I’m not obligated to complete your homework assignment as a prerequisite to posting here. I’m sorry if that troubles you.

You seem to enjoy engaging in hair-splitting "thought experiments." You’ll have to accept that such exercises as imagining that I’m a phono stylus don’t interest me.

Two things you either don’t understand, or don’t want to understand:

1. The thickness of an LP has a trivial effect on VTF. Unless you’re playing discs that are an inch thick, the variation in static VTF between the thinnest Dynagroove LP and the thickest MoFi (or whatever) remaster is trivial. And yes, I’ve confirmed this with an accurate digital scale.

2.) Dynamic VTF - which is influenced by such factors as record warp - is nowhere near the absurd plus-or-minus 50 percent range you’ve claimed, provided that the pickup arm and phono cartridge are properly matched and calibrated. In addition, the use of a dynamically balanced pickup arm will greatly reduced the degree of VTF deviation and, as I’ve previously explained, this can easily be confirmed by observing the phono cartridge’s cantilever deflection as it navigates a warp.

Further, to be clear, the actual sonic benefit of using dynamic balance in a pickup arm is hotly debated, with many arguing that a statically balanced arm delivers better performance. Without taking a side on the debate, it’s clear that the enduring debate itself suggests that the consequences of a cartridge’s varying VTF as it navigates an LP is nowhere near as critical as you would seem to suggest - again, provided the system has been properly matched and calibrated from the outset.

Some users of dynamically balanced pickup arms such as the SME V apply VTF by using equal amounts of static and dynamic force. You might want to try it sometime, if that’s an option for you.

Folfreak, The digital scale that jbny referenced has a non-magnetic weigh pan.  Or at least it says so on the spec sheet to the right of the photo. Thus it should not be influenced by the magnet inside any cartridge, even the stronger magnets in MC cartridges.  That same scale recommended by jbny has evidently been re-packaged to death, in both metal and plastic cases.  I see it all over the place under different brand names, and in fact I own one with a metal case, for which I paid about $50.  I check mine regularly with the reference weights, and it remains very accurate.

You don't understand.  And you don't want to understand.  So why bother?  Read a physics book with a chapter on Newtonian Mechanics.

Or simply do the experiment I suggested: Measure or set VTF with the tonearm parallel to the surface of an LP.  Then place a couple of spacers under your digital scale so that the cartridge has to be raised by a cm or two in order to sit on the weigh pan, and the tonearm is now tilted "up" with respect to the pivot, and measure VTF again.  The difference will be very small, but there will be a difference.  (Which is why I suggest using a digital scale; you'd never detect it with a Shure stylus gauge.)  Don't come back at me until you've done this.  If your tonearm bearings are excessively high in friction, it could obscure or enhance the results.  

You don't seem to get that the thought experiment is valid; if the tonearm is completely vertical, VTF is zero, which means that as the stylus traverses the vertical arc of the tonearm between horizontal and vertical, VTF is gradually decreasing.  

By the way, I never said that the thickness of an LP would make a big difference.  The question was does it make ANY difference.  It makes a small difference. Warps can transiently make a bigger difference.

lewm09-26-2017 3:00pm

Cleeds,
Imagine that you are the stylus tip.  With the arm wand parallel to the LP surface, someone has set VTF for 1.5gm.  Now imagine that you encounter a record warp ...

I understand record warps and the dynamic nature of VTF. That's exactly why I mentioned the differences between statically balanced and dynamically balanced pickup arms.

Imagine that the tonearm has unlimited travel in the vertical plane.  It could then point straight up at the ceiling. What would be the VTF in that case? Zero.

That's absurd, because a pickup arm would never be vertical. The truth is that static VTF - within any normal range of a pickup arm - is not influenced by the thickness of a record.

Do you weigh more when you lie down or stand up?

Cleeds,
Imagine that you are the stylus tip.  With the arm wand parallel to the LP surface, someone has set VTF for 1.5gm.  Now imagine that you encounter a record warp that lifts you up in the air by a few mm during each revolution of the LP.  Since you are subject to gravity, you come back down on the other side of the warp, but during the moment when the warp elevates you off the horizontal, the pull of gravity is still perpendicular to the plane of the LP surface.  Yet the tonearm is fixed at its pivot, so your journey back to horizontal must travel in the vertical arc dictated by the tonearm; the stylus tip (you) cannot follow the true vertical.  Therefore, some of the force of gravity in the vertical plane is momentarily bled off by a smaller force due to resistance supplied by the tonearm, a force vector generated because the tonearm does not let the cartridge fall back down vertically.  Hence "net" VTF is momentarily reduced by a small fraction. Got it now?  

If you don't believe me, and if you have an accurate digital gauge, check VTF when you have the cartridge in the plane of a typical LP and then again with the tonearm elevated by a cm or two above the horizontal.  I think the difference might be detectable even in these two static situations.

Another way to think of it:  Imagine that the tonearm has unlimited travel in the vertical plane.  It could then point straight up at the ceiling. What would be the VTF in that case? Zero.

Older Ortofon DS-1 is cheaper than DS-3
My DS-1 works fine and i like it, my ex new DS-3 was deffected and does not read the weight righ from the start. I think there is no need for DS-3 if DS-1 is available for much better price.   

I don't think it's an issue though. I had a friend bring over his Ortofon DS-3 and it read exactly the same with my cart. My Delos is supposed to be at exactly 1.72 for it's best, so I'm trying to make sure it's as accurate as possible.

@jbny  unless you have calibration weights that are magnetic and non magnetic you will not see the effect we’ve been discussing

my scales all weigh the same with calibration weights, but once you use a MC cartridge it’s a different matter. And most of the China sourced metal ones read the same, no doubt because they share the same internal electronics. It’s only the custom designed plastic ones that give different results

now most setups will not be sensitive to +/- .05g VTF but unfortunately mine is, needing 1.70-1.75 exactly to perform at its best so I have no choice but to pay the $150 cost of entry for the Rega

You absolutely can use the inexpensive digital scales. Don't let anyone tell you otherwise. I have been using this stylus gauge for the last year, it's $14 shipped.

https://www.amazon.com/gp/product/B00XC2AQN4/

I have a set of calibration weights (I use the 1g and 500mg weights) that I use to check it is accurate, so far it's been perfect each time I have tested it. These kinds of measurements devices have been figured out some time ago, no need to spend a lot of money for a digital scale.

dover

I do agree that the deviation in VTF with dynamically balanced arms will be less than statically balanced arms on warps, but don't agree that VTF can be precisely maintained over a warp even with dynamic balancing, unless of course you consider +- 50% precise.

Don't be silly. The effectiveness of dynamic balancing in achieving relatively constant VTF over warps can easily be observed by watching the deflection of the cartridge cantilever.

A 50 percent deviation from ideal VTF would cause serious mistracking with many cartridges.

@cleeds 
We'll have to agree to disagree.
I do agree that the deviation in VTF with dynamically balanced arms will be less than statically balanced arms on warps, but don't agree that VTF can be precisely maintained over a warp even with dynamic balancing, unless of course you consider +- 50% precise. 

dover.

... Most dynamic balancing is applied with a spring which is designed to provide a restorative force to the arm. The actual tracking force at the stylus will be unpredictable and variable depending on the cartridge compliance, size and gradient of the warp and speed of the record. The competing forces are far more complex - it would be almost impossible to provide a constant tracking force over a record warp.

Provided that the phono cartridge and arm are properly matched, a dynamically balanced arm will provide precise VTF within a very narrow range even over a warp. There may be some deviation, but it will be slight compared to a statically balanced arm.

cleeds
814 posts
09-25-2017 9:45am
Also, if you use a dynamically balanced arm, VTF will remain constant even while playing a warped record.

That statement is not true. Most dynamic balancing is applied with a spring which is designed to provide a restorative force to the arm. The actual tracking force at the stylus will be unpredictable and variable depending on the cartridge compliance, size and gradient of the warp and speed of the record. The competing forces are far more complex - it would be almost impossible to provide a constant tracking force over a record warp.  

lewn....speaking of azimuth.....In my experience, accurate azimuth is even more important than is exact vtf

Also, if you use a dynamically balanced arm, VTF will remain constant even while playing a warped record.

lewm

... gravity is a constant for any particular location on earth, however, actual VTF will vary depending upon where the tonearm is located in its vertical arc.  This happens when you play a warped LP, for example

Varying VTF while playing a warped record is the result of dynamic forces. What we're talking about here is static VTF, which does not "vary depending upon where the tonearm is located in its vertical arc."

Thanks chakster, lewm and folkfreak, very informative.
As folkfreak points out, even scales with non ferrous plates can have inaccurate readings due to strong magnets of MC carts affecting the whole mechanism. That would explain little increase in values with my DS-3, I strongly believe now.
I will try the plastic Rega scale, thanks again for great input.

@lewm funny thing is I even find this with audiophile approved scales with non ferrous pans. They record exactly the same with a static weight like a screw but once I load them with a cartridge they’re all over the place. Could it be that the strong magnets in a cartridge affect the mechanism not just the pan? Anyway I trust the design of the Rega (just like the cartridge man scale I owned before, although that was really prone to breaking down due to its battery design) and it’s one thing I no longer need to worry about

Folkfreak, There are many digital scales on the market that feature non-magnetic weigh pans.  You are quite correct that any scale with a ferrous weigh pan would give an inaccurate measure of VTF and might even result in damage to the cartridge suspension.  However, as noted, this problem is easy to avoid.

cleeds, True, gravity is a constant for any particular location on earth, however, actual VTF will vary depending upon where the tonearm is located in its vertical arc.  This happens when you play a warped LP, for example.  Thus it is important to use a scale that allows VTF to be measured at least roughly in the same plane as that of the surface of a typical LP.  There would be a tiny variation in VTF, depending upon thick or thin LPs, not enough to worry about in my opinion.

Chakster, Like Raul often says, Relax and enjoy the music.  As many papers as there are on using a digital microscope to set SRA, it is nevertheless a skill that can only come from doing it regularly under the guidance of one of the very few experts in the field.  I advise you to do it by ear.  Azimuth is yet another can of worms.

@cleeds

Gravity is a constant. VTF doesn’t change just because one record is thicker than another.

Plastic mechanical scales are 1cm higher than actual record surface, some digital scales are not designed to measure stylus pressure, they are also much thicker. Watch Fremer’s seminar where he said that https://youtu.be/eQDa7suJn64

But now i’m more concerned about cross talk setting which is much more complicated.
Also start thinking about digital microscope, he mentioned this one https://www.amazon.com/Dino-Lite-Microscope-measurement-function-software/dp/B000P43IQY

The problem I have with all metal scales is that they over read cartridge load by appx. 0.1g probably due to the effect of the cartridge magnets. The new Rega scale is plastic so does not have this effect and appears well designed for long term accurate measurement and I can highly recommend it
http://www.rega.co.uk/uploads/hfc-426-re-print-half-rega-guage.pdf

chakster

...  the problem with cheap digital scales and with mechanical scales is that all of them have different thickness, normally thicker than vinyl record, so they are incorrect, because the stylus is not leveled right.

Gravity is a constant. VTF doesn't change just because one record is thicker than another.

@harold-not-the-barrel i have had similar issue from the start with DS-3, even my cheapest digitale scale was better that this Ortofon. I think all ortofons sucking enegry from the batteries too quick. However, my new DS-1 works fine for one year and i think it's better than DS-3. 

P.S. the problem with cheap digital scales and with mechanical scales is that all of them have different thickness, normally thicker than vinyl record, so they are incorrect, because the stylus is not leveled right.  

After nearly 2 years use my Ortofon DS-3 has become unstable. Adjusting tare cannot solve the problem as it will not maintain zero and starts to display 0.01... 0.20 values. Anyone having the same issue... please advice. Thanks

Philb7777, the audio additives scale is completely non magnetic. I double checked last night.

Ortofon DS-3

Another recommendation for the Shure scale. Accurate and easy to use.

Is that Audio Additives scale truly non-magnetic?

I have the identical one from Acoustic Sounds (provably made by the same manufacturer) and its magnetic and still needs taring when I put my cart hovering over the weigh scale area.

The Audio Additives gauge from Music Direct reads to three decimal places. I have found it to be accurate and consistent. It appears well made(china) and is only 79.99. Another benefit, battery requirements are triple A's not the high dollar watch type batteries.

I very much agree that the Shure scale is good enough. After getting the VTF in the "ballpark", you should experiment with a little more, and a little less to find the optimum for your cartridge. All that Dougdeacon said is "golden", ...I have an electronic scale, but its really not needed.

The Winds ALM 01 is the best good to 100th of a gram.I once had a $50.00 one it was junk it depends on how good a table,arm and cart you have.

Beautiful! If you are fond of contemporary products I'd advise checking the following link: http://www.medicalexpo.com/medical-manufacturer/platform-scale-608.html. Hope you enjoy it!