Any scale should read zero before lowering the cartridge onto the platform. If your scale reads anything else, then something is wrong with the scale. Did you replace the battery just to make sure that is not the problem with your scale?
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Thanks for the info Yogiboy but these scales that are magnetic are well described and actually the scale platform is metal enough to have a magnetic attraction towards the magnets in the cart. This causes a negative deflection in the scale reading when having the cart just above the scale. My batteries are new.
I'm wondering if the Audio Additives care has a scale platform that is not magnetic. I'm doubtful of this due to the Acous Tech (Acoustic Sounds) one looking identical and its magnetic.
This is the best scale, IMO. Non magnetic and accurate. They are only sold out of Japan. That is where I ordered mine.
Thanks for the link Christian, I just ordered one today. I'm ready to quit guessing on my actual VTF, even if my digital force gauge gets close. The deflection of -0.40 to -0.50 prior to lowering the cart bothers me . Some say it doesn't matter, others say toy should tare to zero and the measure. Hopefully the ortofon ds-3 will solve this for me. With spending thousands on carts, I don't mind spending $130 to help ensure accurate VTF. I know many to still use the Shure scale, but I'm all thumbs and went something digital.
I've had the AcousTech digital for some time now, which I've verified to be non-magnetic in a variety of ways. Wish I had known about the Ortofon scale, before that purchase. That's a really nice looking unit, and it appears that the stylus would sit closer to the level of a record surface, as well.
It's interesting but I checked the AcousTech too after some answers to this thread. It is indeed non-magnetic when tested with a magnet both on the case and the scale platform. Weird how with my Dyna carts when having the cart body hovering over the scale platform I get varying readings from -0.035 to -0.055. To tare to zero or not to tare? Hmmmm.....
If it is not a magnetic 'pull' doing this then what could it be? Some weird electrical interference? I know a few others that had this happen with some digital scales and their carts including Dynas, Ortofons and Lyras.
Don thanks for the reply and info about the A/V Solutions site and the Ortofon DS-1. Unfortunately the DS-1 is only sensitive to 0.1g and the newer DS-3 is sensitive to 0.01 g. All our ears are different, but I can definitely hear changes in 0.05g of VTF. So I went for the DS-3. Thanks again for the info though!
It is important to realise that the magnetic attraction is cancelled out when the stylus rests on the weighing platform. Zero before bringing the cartridge near the scale and then ignore the negative deflection as you lower it. I went through a lot of thought about this problem, and did all the stupid things like re-zeroing, with the stylus just above the platform.
The answer is the Ortofon DS-3 the weighing platform is almost exactly at the thickness of a record, and it is not magnetic. Seems like it is only available in Japan. This is important on some arms, my Kuzma 4 point gives very different weights depending on the height of the measuring platform, up to .2 of a gram. The centre of gravity must be way above the level of the record, on this arm.
Dinster, can you help me understand why taring or zeroing isn't necessary?
I get two distinct different readings when zeroing and nor zeroing. One would think if it didn't matter then whether you zeroed or not you would get the same reading when the stylus touched the platform.
Could you explain your reasoning? I'm just trying to learn, etc and sort my thoughts through this.
Before lowering the cart. to the scale, the cart./tonearm is supported by the tonearm rest. The magnet in the cart. pulls up on the pan of the scale giving the negative reading. This force is being countered by the tonearm rest. Once the tonearm is released that is no longer the case. All the weight of the cart./tonearm is now resting on the scale. So, zeroing the scale while it reads negative in this case will cause the final reading to be too high. The cart. will still be attracted to the scale; which will cause the cart. to sit somewhat lower on the scale. The effect of this on the measured weight should be small.
Whether this magnetic attraction needs to be tared out depends on which part of the scale the cartridge is attracted to:
- if the attraction is to the weighing surface, which sits above the load cell, then it should not be tared out;
- if the attraction is to something beneath the load cell, then it should be tared out;
- if the attraction is to both the weighing surface and something beneath the load cell, then the attraction due to something below the load cell should be tared out and the attraction due to the weighing surface should not be. Good luck with that.
We've had this discussion before, recently. John tracy and Dinster acknowledged these facts then. I don't know why they're reverted to a "one answer fits all" position but either answer is an over-simplification.
That said, all the above is much ado about nothing. Just use a scale that has no magnetic attraction. Whether it affects the indicated VTF or not, that attraction stresses the cantilever and suspension. It's an easily avoided risk that no one need take.
Personally, I've been using Yogiboy's approach for 12+ years... a gunpowder scale with a DIY weighing step made of non-magnetic material. Works perfectly and safely, measures to the nearest .001g, less costly than any audio branded scale.
Stringreen, , I agree with you with one exception (and provided that one's Shure balance is made from non-magnetic material... some aren't).
The exception is anyone who swaps out cartridges frequently. They may benefit from a scale that provides precise, repeatable results, as it allows rapid dialing in of the known, preferred VTF for a particular cartridge. Tweaking by ear is quicker if you start within .01g or so of the ideal.
Horses for courses, of course.
I used a plastic library card that was a bit thinner than a credit card. I cut off the magnetic strip just in case, and needed to make it more narrow anyway. I then bent it so that the weighing step was at the record's level. I then used blu-tack to attach the other half to the weighing surface of the scale. Voila.
Why don't you place the stylus on the scale, and then turn the scale on? If the scale is calibrated correctly, once you turn it on, the reading will indicate the VTF only with a negative sign. I tried this way many times with my electronic scale that was also showing a negative reading as I lowered the cartridge, and the results were consistent.
Actusreus - thanks for the tip regarding the weighing platform. After some research I found that this Proscale LC50 is the one used by Clearaudio in their $250 stylus gauge fitted with a plastic weighing platform. You can use the plastic cover that comes with the scale as the base of a platform, turn it upside down and affix a small L-shaped piece of plastic to its side, setting the stylus platform to be at the desired height of a record. The scale automatically adjusts its zero point to compensate for the weight of the platform, or you can manually reset it using the tare function. That does the trick, awesome!
Bill, similar to Actusreus, I often suggest cutting up some credit cards and glueing the pieces together. It's bound to save you some money. ;-)
Seriously, mine is made of a 1" wide length of copper strip. I folded it over several times to center most of the weight on the weighing platform for stability. Then added an "S" curve to drop down to a record height shelf for the stylus. The copper's fairly thin, so getting to record height without touching the platter is easy.
Digital scales use load cells. Load cells are most accurate/reliable when weighing near the middle of their range, least accurate/reliable when weighing at either extreme.
So, make your DIY step's weight = half the scale's capacity minus 2grams. You'll be measuring VTF in your scale's most accurate region.
Example: I use a MyWeigh scale of 50g capacity. My copper step weighs 23g. Adding the typical ~2g of downforce from a cartridge puts me at the midpoint, which should result in the most accurate/reliable readings.
A bit of harmless OCDing, which many vinyl-philes enjoy!
Doug, I didn't mention the possibility of the cart. being attracted to something in the body of the scale so as not to confuse the issue. The problem as stated was a negative reading before the stylus touched the weigh pan of the scale. This can only be caused by a magnetic attraction to the weigh pan. Any attraction to something in the body of the scale will affect the measured weight only after the weight of the cart. is resting on the weigh pan, not before. The advise to not use the tare button to zero out the negative reading is correct. If anyone is worried about this other issue that you brought up they can adjust the counter weight on their tone arm so that the arm is in balance (zero VTF) and position over the scale. If there is an attraction, the scale will read what it is and this value can be used to correct further readings. IMO what is important here is the repeatability of the scale, not its ultimate accuracy. Since one will set the VTF by ear and having the ability to make small, repeatable changes is what matters.
IMO what is important here is the repeatability of the scale, not its ultimate accuracy. Since one will set the VTF by ear and having the ability to make small, repeatable changes is what matters.
The tip above about using a load cell near the middle of its range will improve its repeatability and its accuracy. Load cells behave with increasing randomness as a function of the distance from the mid-point of their capacity.