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I have an AcousTech digital stylus force gauge. When trying to measure VTF with a Benz Ruby 3, a cartridge with a strong magnetic field, hovering the cartridge above the gauge causes erroneous negative readings. Per an Absolute Sound setup article, you should tare the gauge if that happens. When I try that, the gauge struggles to zero out but eventually loses to the overwhelming magnetic field. Plus, I get a reading when setting the cartridge down which is too high by about .6 gm. If I simply tare the gauge with the cartridge well away, the reading is about .2gm +- the reading I get with the Shure Stylus gauge, so I *think* the reading on the digital gauge is within reason, but I'm not sure ow accurate it is. How do I get an accurate reading with this cartridge? Is there a digital gauge that is immune to these magnetic fields?
Follow Ups:
I can't say I see the need for the precision of a digital gauge for initial cartridge set up. So long as the VTF is within the recommended range, is not the final setting then done by ear?
The value I see with a digital gauge is to measure VTF after the optimal setting is determined. Then for those who swap out cartridges it would be easier/faster to reset to that value whenever that cartridge was put into play again.
"The piano ain't got no wrong notes." Thelonious Monk
Well, you can talk about setting it by ear, but the fact is the manufacturer recommends a setting (or range) that puts the coil in the proper relation to the magnet. If you think it sounds better elswhere go for it.
I assumed the set up would be within the manufacturer's range. But sometimes that can allow a fair bit of attitude in finding optimal sonics.
"The piano ain't got no wrong notes." Thelonious Monk
The dig. gauge I use shows a similar issue on some of the readings. I just zero it out before each measurement. It's Al+ but I think the cartridges magnetic field plays around with the electronics a bit. I will have to do a double check and see how conductive it is. The other thing I noticed is that the effect stops when the cart. reaches a certain distance as it approaches the meas. position.
I have a cheap two part plastic Shure gauge someone gave me years ago.
I find it is all I need.
The damn electronic scale I bought would need new batteries every time. and seemed a PITA to use.
The Shure is EASY to use. And may just last for ANOTHER 50 years.
nt
.
nt
I'm sure I've seen scales like that in a head shop 25 years ago.
On the original topic I too get a reading with a hovering stylus above the plate, I also get different readings depending on stylus height due to the arm geometry. There is also some variation depending where on the plate the stylus lands but there is a least a dot to aim at. Amongst all this I don't expect an accurate reading but if I hit close to the same spot each time and I don't adjust the arm pillar height I can get a fairly precise one which serves as a reference while adjusting VTF. My ears can tell me if it needs more or less, though not always straight away.
I think making it slightly larger could have the accuracy doubled.
With a slightly tighter pointer.
Hey! all you entrepreneurs. Start making this device.
The patent has to be expired (if it was ever granted. (pat. PENDING..).. And if it is not.. who is gonna know!
Does that mean you wouldn't be interested in these? :))
I have never worried about of those things which make some vinylists heart flutter like "VTA" or 'geometry' or anything.
I buy a new cartridge I plop it on the arm end SOMEPLACE which seems OK. The fiddle the weight to around what it is supposed to be.
Then I listen to music.
I never go back and check anything until I buy a new cartridge.
As long as the music sound good. I do not care about VTA or that stuff.
So for me, the Shure plastic gauge works great.
I get very accurate readings with my digital scale. All my cartridges are moving coils with powerful magnets so I built a special platform from an old credit card to keep the cartridge away from the scale and also keep the stylus at the same level as a vinyl record.
I tried that sort of thing (originally shown by Wally M) with one of my scales, a "My Weigh" a very accurate scale, and it gave me clearly erroneous readings. Seems that it did not take well to the torque imposed upon the platform. As usual YMMV.
Thats' too bad! Mine seems to have perfect accuracy. I have a 5-gram calibration weight and it measures perfectly. I've constructed some smaller calibration weights and they measure perfectly, too.
Good luck,
John Elison
Wally used to use the "My Weigh" same as mine. I use it off to the side to get to the right height. Also have one like the OP's off ebay for about $10. They measure pretty close, certainly identical for 1/10 gram
Since there is a plethora of digital scales with non-magnetic platforms (see below) and also with platforms that lie in the plane of an LP, unlike the one in the photo, there really is not a problem for a prospective buyer.
My scale does not have a magnetic platform. However, the scale is affected by the powerful magnet in moving coil cartridges, which causes erroneous readings. The platform isn't magnetic, though. If it were, the cartridge would be sucked down to the platform thereby compressing the stylus until the cartridge body was resting on the platform. This doesn't happen. It just gives erroneous readings.
Best regards,
John Elison
nt
Sorry. If it's not specifically stated, most of the digital scales that are sold under different brand names and made of either plastic or metal, are all the same product under different guises. If it looks like the one shown in the below referenced URL, by Fremer, it's going to have a non-magnetic platform and is designed such that the stylus tip is at least roughly in the same plane as the surface of an LP. Of course, any prospective buyer should take a close look at the specs of THE particular gauge that he or she is going to buy. I certainly haven't vetted every single variation on the theme, and for all I know the very cheapest variations may be magnetic.
but it's $80 compared to the $30 scale john elison showed.
...regards...tr
Edits: 03/15/17
for $50-$60, if you shop. That version has a metal casing, which I like too vs plastic, but the plastic version may work just as well and be just as reliable, for significantly less money. The type of scale shown by Fremer may be a more recent product than the one owned by John and shown in his photo. I don't know for sure. In any case, it's non-magnetic and has its platform more nearly in the same plane as the surface of an LP, when you set it on a platter mat. The cost differential between John's scale and the scale promoted by Fremer at whatever price is a matter for a buyer to consider.
I did not originally intend to argue that one digital scale is better than another, but I do like the digital scales that are on the market much better than the old school Shure SFG. I've got two SFGs lying around, if anyone wants one for the cost of shipment.
nt
nt
I bought a "no name" digital stylus force gauge from a Chinese vendor on e-bay for $10 over three years ago. It still works just fine. I've seen it (the same one) advertised by one "high end" audio dealer for $80 and by a competitor for $50.
It reads the same as my old trusty SFG-2 and is (at least for me) easier to use.
One of the nice things about this cheap little Chinese gauge is that it's non-magnetic!
Just a hint :-)
Cheers,
SB
Exactally, which is why I still use mine. Takes under a minute and no batteries or magneticusses.
how do you get the SFG2 to produce readings like "1.732 grams"? Having used one for decades, until these digital scales came on the market, I usually found myself straining to feel confident that I was at "about" 1.5 gm, or etc. The digital scale is sooo much more precise and repeatable that I would never think of going back to the Shure SFG.
Some of us claim to hear significant differences between 1.6g and 1.7g VTF, for some particular cartridges. Speaking for myself, I could never feel confident that I could distinguish 0.1 g differences with the SFG. How do you even set the counter-wt for a difference that small?
> The digital scale is sooo much more precise and repeatable that I would never think of going back to the Shure SFG.
My sentiments exactly! It's much more convenient, too.
The Acoustech gauge is the Camrong one from China as sold by and branded by many companies. I have been using one for years and have never experienced any difficulties with magnetic fields . What is unique about the Benz cartridge that makes its magnetic field different to that of other expensive MCs using rare earth magnets?Anyway I am not sure that I understand what you are doing. You say that you take the gauge and you tare it. OK so you should have no load on the gauge. Then you press the Tare button. You wait until the display shows CAL then when it flashes you place the supplied 5g weight on the load pad and wait for the display to settle. Eventually it shows 00.00. Remove the weight then put it back so that the gauge is now reading the weight again. Instead of 5.000 it will probably show, say, 5.004 as that is the limit of its accuracy (NB: more than required for setting VTF). Is this what is happening away from the cartridge?
OK, assuming that all is OK so far, how do you then know that when you set the cartridge down on the load pad the reading is too high by 0.6g (rather a lot). How are you measuring this? Are you checking it against another gauge? How do you know which is accurate?
We know in my example above that the gauge over reads by,say, 0.004g. However in accuracy terms that final decimal point is unreliable and should be ignored anyway. BTW the supplied 5g weight is not accurate to that level and laboratory weights that are would cost more than the gauge (at least for the average price of this gauge which varies from one brand to another). Note that the repeatable over reading in my example is a tiny amount yet you are saying that even away from the cartridge when calibrating it the reading varies by ± 0.2g which for this or any gauge is high.
Please also note that the reading will vary if the gauge isn't on a perfectly level surface or if the load is placed other than exactly on/within the black dot target. Also when using it needs time to settle.
Given the levels of misreading that you quote I am not rejecting the possibility that the sample of gauge that you have is faulty ( if you are using it correctly).
As for magnetic attraction the gauge is made of plastic and the only metal surface is the brushed aluminium (non-magnetic)surround to the load pad. So I do not understand how the Benz is attracted to it. I just checked mine against a magnet and there is no attraction at all.
How does the gauge struggle to zero out when you tare it " due to the overwhelming magnetic field " when the process of calibration does not involve the cartridge at all?
Edits: 03/15/17
I'm not calibrating the gauge, just taring it to zero it out. I'm coming up with .6gm figure because if I just take the VTF reading, I get about 2 gm. If I try to tare it to zero first when the cartridge is hovering above, noting that the gauge fluctuates ever more wildly as the cartridge is brought closer and closer until it's just above the weighing platform, not only are my efforts to zero the gauge unsuccessful, but the reading with cartridge on the platform is about 2.6 gm. The Shure gauge confirms that's not correct. Even with it's inaccuracy, it shows roughly 2gm, although it may say 1.8 or 2.1 or something like that - not precise as we know about the Shure gauge.
Apparently the Benz Ruby 3 has a high magnetic field. I also can't use the VPI platter ring because of its ferrous content, which forcibly draws my cartridge to it - it almost bent the stylus.
Also, I think people are getting confused about the materials used in the digital gauge. It doesn't matter that the gauge platform is plastic and aluminum. I'm contending that the strong magnetic pull is interfering with the electronics within the gauge.
I am suspecting that you either haven't got or haven't read the instructions.You cannot "zero" the gauge by pressing the TARE button. The TARE button opens the calibration program which is its sole function ( display shows CAL when you press the TARE button for a few seconds) for which a 5g weight is necessary. When the gauge establishes the 5g load it then resets its zero calibration. If you haven't used the weight then this is why your attempts have been unsuccesful . If you click the link you will see your gauge and you will see that the weight needed to set zero (calibrate) is clearly shown. Do you have this? If not or you don't use it then you have never set the zero calibration and this is why the readings you have are odd.
Do you have a suspended turntable? If so I would point out that any cartridge will make the gauge change figures as you move the arm towards it as you are also moving/shaking the whole turntable by a tiny amount which the gauge is sensitive enough to register. Nothing to do with magnetism. My one behaves exactly like this. You need to move the cartridge to its correct place above the load pad and then leave it in raised position until the gauge returns to zero. Only then lower the cartridge and take the reading once the gauge settles again ( you can tell when it has as a small circle appears in the top left of the display). It is not an instant process.
BTW, The company that makes these gauges makes at least three variants. One displays to two decimal places, one to three and there is also a "giant" sized version that also displays to three places. The two place gauge is cheaper than the three place one and many people complaining about the price variations ( although they exist) do not appear to know about these variants and seem to assume that they are all the same.
I have never seen one made from metal as one poster suggests although some of them, like my one, use a plastic and finish that looks very much like metal.
They are surprisingly accurate when used correctly. I have several laboratory weights accurate to two decimal places: 5, 2 and 1 gram. Not only is the gauge accurate (I have a three place one) to two decimal places, it is also linear i.e. equally accurate at other loads not just the calibration one. I assume that the two place type is accurate to one decimal place.
Correction: I have been playing around with mine and found that the TARE button will set a zero figure ( not shown in my instructions). As will just leaving the gauge without any load. However that zero is not in relation to anything without the weight having set the calibration in the first place. My experiment showed that even breathing lightly on the gauge canged the weight displayed, including zero. That's how sensitive it is.
Edits: 03/15/17 03/15/17
I gather the basis for your idea is that the gauge readout goes unstable when the cartridge even approaches the weigh pan, without even touching it. Is that so? That's interesting. I will have to check it out with mine. I've owned mine for several years now. Since I have all too many cartridges and turntables, I use it quite a bit. It's always rock steady in read-out and never reads anything but zero when tared with no weight on the pan. My scale is identical to the one shown by Fremer in the URL I posted above (but I did not pay $80 for it).
If your weigh pan is magnetic or if something under the weigh pan is magnetic, I could imagine that the readout would go unstable even with the cartridge hovering over it but not touching it, because in that case the magnetic attraction would be pulling upward on the weigh pan, which would no doubt perturb the readout.
I have the same metal bodied (I assume it is metal) as you do and have the same issue with my Ortofon Jubilee. The weight goes nuts while lowering the cart down to the measurement point. I constructed a similar gizmo as JE and the 5 gm weight reads the same whether on the platform or cantilevered off on the gizmo. Interestingly, once the cartridge is on the platform or the gizmo, the final weight is close to the same. I just do both measurements and compare. Then I don't worry much because they are very close and I have bigger things to worry about these days.
I have an Ortofon MC2000, the vintage MC with vanishingly low output. I was lowering it down on the platter of one of my DD turntables when it suddenly got sucked down flat onto the platter mat. Fortunately, the suspension took the hit and seems to be OK. I was using an LP-sized piece of TI Shield under the platter mat, to block EMI from the motor from causing issues with induced noise. Turns out TI Shield is partly ferrous and its ferrous layer was being magnetized by the underlying rotor of the DD motor. That was too close to the magnets of the Ortofon, and the two tried to kiss each other. This had never happened before with any other (non-Ortofon) cartridge. Later on, an Ortofon guru told me that they tend to place the magnet near the bottom of the cartridge body which makes it susceptible to this sort of accident. Maybe your problem with your Orto is of a similar nature. When I removed the TI Shield, the problem went away entirely.
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