Stylus force digital scales


Digital scales from Clearaudio and others range from $200-500. Amazon has 'em for $20. Why cant I use one of these instead and save big bucks?
tbromgard
One problem I found from my $30 digital scale is the battery dies within a month. Used or not.
Then it was hard to use.
I find the cheap plastic manual Shure scale to work well.
And use that only.
I have one and it works well. It takes watch batteries so pricey to replace. I had the AcousTech- $80, pc board made by the same company- and it operated on two AAA batteries and had an aluminum case. They do stop functioning if you drop them. Both had very repeatable measurements and a calibration weight. The AcousTech held calibration well. Not so much the Amazon version.
You can. I use a digital jewelry/gunpowder scale that I bought about 15 years ago for ~$50 . Similar models are cheaper today. I've changed batteries once in all those years, no issues there.

Two issues to be aware of:

1. Many scales are magnetically attractive. The magnets in a cartridge (especially the powerful magnets in LOMCs) will pull the cartridge toward the scale - skewing results and even risking cantilever damage.

2. Most scales are much thicker than an LP, which would put your tonearm at a more upward angle than when playing music. On most tonearms, an upward (or downward) angle will change the downforce on the stylus. Again, this would skew results.

Both of these issues can be addressed simply and at virtually no cost by using a weighing step... a doohickey that sits on the weighing platform of the scale, projects off the side, then drops down to a step that's at LP height. You put the stylus on the step, not on top of the scale.

You can DIY a weighing step from any rigid, hard, non-magnetic material. You could cut up several credit cards and glue the pieces together. That would make a workable step and save a fortune in future debts, lol!

***
With a little forethought, a weighing step can provide an additional benefit. Digital scales use a load cell to detect downward pressure. Load cells are most accurate in the middle of their range, less accurate near the extremes. The tiny pressures we're measuring with stylus downforce fall far below the midpoint of most load cells, near the low extreme where they're least accurate.

You can address this by making the mass of your weighing step equal to one half the capacity of the scale, minus 2gm or so. (Example: for a scale with 50gm capacity, make your step weigh 23gm.) Voila! Now you're weighing downforce at the load cell's midpoint, maximizing accuracy. Place the step on the scale, tare to zero and away you go.

***
Or you could do what Elizabeth says. I'm personally more comfortable with my digital scale than a cheap plastic balance, but whatever works for you. Just remember, a scale cannot tell you what the right VTF for any cartridge is. It can only put you in the ballpark. After that, you must fine tune by listening.

one word of caution

If you are using a Clearaudio table with one of the magnetic field arms, you must make sure that the scale measuring point is at the exact same height as the record surface otherwise it could be off considerably.

I use the cheaper model electronic scales ( I have two), and the clearaudio teeter totter scale. When using the cheap electronic ones, I just make sure that I verify their accuracy by measuring the weight of both a penny (2.5 grams) and a nickel (5 grams). Batteries are low when they are off on mine.
http://www.usmint.gov/about_the_mint/?action=coin_specifications
Winds ALM -01 is good to 1/100th of a gram it is the best $30.00 gauges are not accurate.
Best digital scale I have used.

http://www.musicdirect.com/p-204-audio-additives-digital-stylus-force-gauge.aspx
If you don't want to mess around with modifying a scale as
Doug suggests, then pick up a Cartridge Man scale. It's
spendy, but is designed well and is rechargeable.

Although, I may be inclined to try Doug's excellent idea if
my Cartridge Man scale dies on me in the future.
After buying and trying many digital scales used for the specific application of measuring tracking force, I agree with Don. This version is clearly superior when compared to similar but smaller scales that use button style batteries. It has the best most solid construction quality, has a non-magnetic platform, measures at the proper height, and provides reasonably consistent readings.
Doug, any magnetic attraction with not affect the weight measured. You will see the scale read negative as the cart. nears the scale; but that's because it's being supported by the cueing mechanism. Once the cart. is released all its weight is on the scale and will be measured, magnetic attraction or not. Think about it.
I use the cheaper model electronic scales ( I have two), and the clearaudio teeter totter scale.

Jim, have you compared how well the clearaudio does next to the digital scales?

I used one of these digital jobs for a while until one of the segments in one of the numbers died. Made figuring out the actual tracking force a real guessing game. Not sure I want to spend so much money again if the same thing were to happen.
John_tracy is absolutely correct, once the weight of the cartridge is supported by the measuring platform the magnetic force is neutralised, as he says "think about it".
For me the most crucial issue is that the height of the measuring platform is exactly the same as the height that the surface of the record would be. Even small differences less than 1 mm can influence the force by >0.1 gram. This obviously depends on where the the centre of gravity of the tonearm is, these numbers refer to the Kuzma 4 point. I suspect that people who change the tonearm height for different thickness records, are actually hearing the change in tracking force, rather than VTA/SRA, since such small adjustments make hardly any difference to VTA/SRA but make a huge difference to tracking force.
I have found the Ortofon DS-3 (only available in Japan) to have a measuring platform, close to the thickness of an lp. The Clearaudio is much too high as are most of the others, including the el cheepose.
Whether or not the tracking force is affected by magnetic attraction depends on what the LOMC cartridge is attracted to. If it's the platform alone then yes, the scale will read true. But if the cartridge is attracted to internal components or the chassis of the scale then no, the cartridge will be trying to pull itself past the platform and the force will not read true.

And even if the cartridge is only being attracted to the platform, a strong attraction will collapse the cantilever suspension when the magnets within the cartridge body pull the cartridge onto the platform. It may weigh correctly, but the stylus and cantilever will be shoved up against the cartridge body. Trust me, I've seen it happen. :-)

My recommendation is to buy a good durable scale and make a platform adapter out of an old pre-paid "credit" card. I tried one of the low profile "audiophile" scales but it was fragile, not very consistent, and it failed after about 18 months. The scale I ended up with is a My Weigh Palmscale 7.0. It's built like a proverbial tank and is extremely consistent in VTF measurements. Unfortunately My Weigh doesn't carry it anymore but it's still available from many retailers. Their are other scales from My Weigh that would work as well. The prices are reasonable and they have a great warranty policy.

Here's a picture of the credit card platform adapter:
John Elison's example posted at VinylAsylum

You don't need to cut the card down if you don't want to. You can make the adapter so it sits a little too low and then adjust the height above the platter by adding shims.

Regards,
Tom
great tips - thanks guys.
I made something similar out of two pieces of acrylic and a long bolt to use with a lab style full size top loader. Works great.
Although a bit pricey, you might consider checking out this
Ortofon gauge. It puts the stylus at lp height and its flat measuring surface works well with cartridges with very short cantelevers like my Transfiguration. Good luck.
I used the Shure for decades, but earlier this year purchased the Ortofon. Seemingly good build quality and very easy to use. My only criticism is that the platform doesn't have any markings to indicate the center point.

The Ortofon confirmed that the Shure is more than adequate for the job as far as accuracy goes. This makes the Ortofon more of a luxury item as opposed to an essential accessory.
Ortofon gauge looks nice but it's basically a standard digital scale with an alloy platform adapter/extension. You can buy a good digital scale that's (probably) more durable with better button layout and easily make your own platform adapter/extension for a third of the price.

It won't say "Ortofon" though. :-)

I'm using a DIY platform extension with a Dynavector 17D3, which also has a very short cantilever and the setup works great.

Regards,
Tom

PS: I'm not intending to "dis" the Ortofon gauge; I'm sure it works well for measuring VTF. But the original question was "Why cant I use one of these [inexpensive digital gauges] instead and save big bucks?" The answer: You can.
Johntracy and Dinster,

My apologies for not making a long post even longer to thorough explain how magnetic attraction:
1) may increase the downforce recorded by a scale, and;
2) will increae the compression of cantilever and suspension beyond the downforce applied by the tonearm.

Tom,

Thanks for adding the details... bingo.

BTW, my scale is also a My Weigh. Bought it 10+ years ago and it's as good as new... and just as accurate as Ebm's $300 Winds, lol.


P
Is there a sonic benefit for having better than 1/10th gram accuracy?
Onhwy61- It's not necessarily the accuracy, it's the precision. IOW, it matters not if the VTF that sounds best to you is, to make up an example, 2.12, 2.13, or 2.14. Or in fact any value between 2.1 and 2.2 gms. However, once you determine the optimal value, you would like to be able to get back to that # w regularity, if you need to, for any reason, dismount and then remount the same cart. If your scale can only display to 0.1 gms, you will not be able to get back to that "optimal" VTF other than by trial and error. OTOH, if your asking if differences of < 0.1 gms are audible, then I have to say it's up to you and the resolution of your entire system. I know Doug can hear those differences on his system, and I'm pretty sure I can, too. Not necessarily 0.01 gms, but 0.05 for example. YMMV.
I would advise against the Sure scale. I happened to have two identical Sure scales and they were very off against each other. Will never trust them again.

I currently use an APTP445 scale, which is digital and cheap (more or less $10 on ebay), but works well. It's too thick as it is so I made a step out of a credit card and a little bit of Blu-Tack to measure the VTF at the record level. I regularly re-check it with a 5-gram reference weight and it appears to show repeatable measurements. For those on a budget it's a good option.
Swampwalker, thanks for the informative answer.
I meant "Shure" scales. My apologies for the misspelling.
YW, Onhwy. All part of the service ;-)
Dougdeacon, thanks that is something I have not thought about. I have confirmed on my el cheapo digital force gauge that it does measure the correct weight despite the attractive force by zeroing with the cartridge on the platform, and then lifting the cartridge away, and it gives the exact negative reading of the force I set in the first place. The magnets on my Lyra are unbelievably strong and I'm sure the force on the suspension during measurement is not good for the suspension...finally a reason to never measure with a gauge that is magnetic, and a compelling one!!
according to my new digital force gauge my loading was heavy by over .25 grams. it made a substantial improvement when I decreased the weight. I previously used an ortofon scale which was difficult for me to get a good reading. cheers
I was setting up my clear-audio with a Steve Blinn Digital and ended up with better results using the clear-audio included manual gauge. Go figure like Jinpitsburgh said.
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!
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.
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 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.
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.
Another recommendation for the Shure scale. Accurate and easy to use.
Ortofon DS-3
Philb7777, the audio additives scale is completely non magnetic. I double checked last night.
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

@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.  
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.
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

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

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

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 
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
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.