Electronic stylus force gauge question

It is actually quite simple. Those generic pressure gauges marketed under various brand names have a magnetic (Stainless steel) plate. This is attracted by the cartridge magnet as it gets closer, hence the negative reading. Depending on your cartridge the reading may be quite large. However, once the stylus makes contact with the platform the magnetic attraction is cancelled out. This can be verified by zeroing the gauge with the stylus resting on it, and then lifting it away, the negative reading will be the same as the positive reading you would have measured the conventional way. You will track far too heavy if you zero the gauge with the cartridge in close proximity.

I think I might have outsmarted the scale! I placed the stylus on the weighing spot and then turned it on. It showed 0.000 grams as I expected, but when I lifted the tonearm, it showed a negative reading of...1.778 grams! I repeated the procedure several times and the reading remained consistent. I then repeated the procedure with the scale turned on before placing the stylus, and despite the negative reading the result was the same so it appears the negative reading does not factor in in the measurement.

I know - I need to get out more often. Thank you everyone for the input and advice. May your Friday night be more exciting than mine :)

Al,

I thank you for the good night's sleep I'm going to get tonight :)

If the cause is magnetic attraction, once your finger or the cuing lever has released the pick-up arm all the weight will be carried by the scale; no correction needed.

If your goal is precision (repeatable results) as opposed to absolute accuracy that's easy to determine. Make several measurements and see if the are the same. That is if your arm is not like my OL with its dual pivot construction ( the point of the vert. pivot does not always return to the same spot in the jeweled cup due to planned slop).

Hi Marek,

None of the electrical effects I hypothesized would be harmful to the cartridge (or to the gauge, for that matter) in any way.

Best regards,
-- Al

Al,

Thank you for your plausible hypotheses. Something tells me you're probably right, as usual, if not about both, at least one of them :)

Now the question I have to ask: can any of this be harmful to the cartridge?

Marek (Actusreus), as an electrical person I'll offer an electrical hypothesis :-)

If, as you suspect, magnetic effects are not the cause, one guess is that the electronic circuitry in the gauge is being affected by either stray capacitance between its various circuit points and the tonearm/headshell/cartridge assembly or the wiring it contains, or by low-level EMI/RFI being emitted from that assembly.

Sensitivity to those kinds of effects could very conceivably vary as a function of battery strength (consistent with Phil's observation). It could also be expected to vary unpredictably during the tonearm's descent, as the angular alignment and the distance between the gauge's circuitry and the tonearm/headshell/cartridge changes.

Alternatively, it could be that digital noise generated by the gauge's circuitry is radiating through its display window (the one part of the gauge that appears to be electrically unshielded across a significant area) into the tonearm/headshell/cartridge assembly, and radiating or capacitively coupling from there through the air into the metallic structure that the stylus is being lowered onto. From there the noise would re-enter the gauge's circuitry, coupling into different circuit points than those from which it originated, again with unpredictable effects.

These kinds of effects could perhaps be viewed as electrical counterparts to the kinds of mechanical effects Doug was referring to in his comment that "ANY scale that resolves to .01g or better will respond to the slightest changes in air currents. I can alter the reading on my scale (different brand, same resolution) by waving my hand over it." :-)

Best regards,
-- Al

I will give it a shot, even if it's very early and my first cup has not kicked in yet.

Any scale, digital or not, reacts to downward force which causes a downward mechanical action. The cartridge sits on a platform and the amount of downward force is interpreted and displayed as a number. If the platform or any part connected to it has any ferrous parts, as the cartridge's magnets approach the scale from above (as one lowers the arm) they attract these ferrous components upward causing the negative reading. Maybe?

Hey John,
You're absolutely right. In retrospect, I wish I had not written the passage about tracking as closely to 1.75 g as possible. The main impetus behind my original post was the concern about the accuracy and reliability of the scale and measurements, not the obsession with the magic number of 1.75. Little did I know I was about to open a big can of worms...

I am sure that the minus .01g - .03g reading is caused by the magnet in your cart. pulling up on the scale. This could be confirmed by passing a magnet close to the scale to see if the same thing happens. As far as setting your cart. VTF to as close to 1.75g as possible, consider this: the absolute accuracy of your scale is probably more the +/- .05g! Maybe more if there is no provision to calibrate it with a known weight. My advise is to not sweat it.

Sbrownnw...thanks again for the link to that scale on E-Bay. I just received mine and it does indeed perform fantastic! At just $14.99 plus free shipping, it's a definite bargain. Highly recommended.

Actually, I think good scale and countertuitive are actually very helpful. Granted VTF number is just a guide but good scale and countertuitive for VPI great strenght is about reproducibility. You can do everything by ears but sometimes it is a pain. You find an exact sweetspot once. As most people are, you always have to fiddle beyond the sweetspot to make sure that you really reach the ideal spot. Coming back is so much easier if you have some kind of a target. Once you been there and mark the spot, it is nice to get back there quickly without all the listening step in the middle if you have nowhere to go but only your ears. Lyra's very tight VTF's range and their optimal VTF value also get you very close to the sweetspot very quickly. With Lyra's QC, I doubt that the ideal VTF would differ too much from what Lyra recommended.

Actus....I'm not pontificating ...just wondering why anyone would find an electricronic scale so important ( or the Counterintuitive, etc.) As I said before...there is some (not a lot, but some)variation in the building of cartridges et al that nullifies any exact claim of perfection of downward cartridge force. I have posted this because it is MY expectation that others will also post (on this free and open exchange) giving insights on how to further MY understanding of this crazy hobby. If you agree with my observations fine...of not, fine as well. I believe nothing from the internet, however, I put all information through my "filter" to decide what findings I want to retain, and which to dump. I really like the back and forth though because of enlightenment I find on this glowing screen. By the way...Zie Gazundt means that I wish all who reads (even those that don't) these pages Good Health.

Haha, I hear you! Same here. Consider the question never asked :)

Hmmm I thought it was the cartridge that interfered with the scale. The
amount of time spent on the scale is very minor in comparison to the hours
playing record so I never even thought about it. please don't give me
another thing to worry about :) already nervous enough when playing
records as is :(

Suteetat
I always have similar but not exactly identical problem with most of my cartridges. If I turn on digital scale on first and let it zero first, as soon as I move my cartridge over the scale, it gave negative reading. However the number usually does not fluctuate wildly. The reading is very much reproducible every time. I assume it was just magnetic interference from cartridge or something along that line. Usually I just move my cartridge above the scale first then turn the scale on and let it zero itself then. This happened with my airtight koetsu dynavetor and Lyra with 2 different scale (same made though) so I thought it was normal.

Suteetat (and others),
Do you have any concerns that the magnetic interference might negatively affect the cartridge long term? Beyond inconsistent readings, the icing on the cake would be to damage a few $K cartridge with a cheap scale while trying to dial in the VTF!

Here is another thought as a way to check the condition of your tonearm bearings in the vertical direction. After placing the stylus on your VTF gage and getting a reading, apply a light pressure downward on your counterweight to bring the VTF to near zero and then let go. If the scale has a new reading, that difference is called hysteresis. e.g. let's say your scale reads 1.5g and then you apply a pressure to your counterweight until the scale reads near zero, let go and now the scale reads 1.49g. The hysteresis is the percent difference or in this case 0.67%. For mechanical systems, up to 1% hysteresis is very good. Up to 2% is ok, but considering the quality of our tonearms and bearings used, I would expect it to be less than 1%. Try it in the other direction too. Apply a slight upward pressure on the counterweight to raise VTF by 0.5g or so and then release.
So why is hysteresis a factor? Because as the tonearm/cartridge tracks over a record, any waviness in the record causes the tonearm to move up and down. If the bearings have too much hysteresis then the VTF will be changing slightly- going higher as the tonearm is pushed upward and then being a little lighter as the tonearm comes back down. Aside from inertia, 0% hysteresis means the VTF would stay constant as the stylus tracks over a wavy record.
The scale itself should have extremely low hysteresis since it is a strain gage. Good quality scales that I have used change maybe one digit out to the third decimal place when I have added/subtracted the load slightly.

Just to add to the fun, I have three arms mounted on two tables, and in each case, my cheap digital scale tells me that the VTF varies depending on where I put the scale on the respective turntables. That is, it measures slightly differently depending on whether the scale is placed where the lead-in grooves are, or half-way in, or where the end grooves are. I find this curious but not really important. Certainly trying to pinpoint 1.75 g -- as opposed to l.72 or 1.78 or whatever -- is not in the cards for me :-)

I always have similar but not exactly identical problem with most of my cartridges. If I turn on digital scale on first and let it zero first, as soon as I move my cartridge over the scale, it gave negative reading. However the number usually does not fluctuate wildly. The reading is very much reproducible every time. I assume it was just magnetic interference from cartridge or something along that line. Usually I just move my cartridge above the scale first then turn the scale on and let it zero itself then. This happened with my airtight koetsu dynavetor and Lyra with 2 different scale (same made though) so I thought it was normal.

Q: Can someone explain the problem with my stylus gauge; it's acting wonky when I take a reading for my cart at 1.75g?

A: Why on earth are you so obsessed with tracking at 1.75g?

I'm no logician, but I believe informally we can call that a non sequitur. I agree though that some non sequiturs can prove educational.

I had a similar experience recently with my cheap electronic gauge and a new cart. The reading would go negative as the stylus approached (but did not touch), and if I hover the stylus a bit above the gauge, the reading would go all over the place. This had never happened before with my other carts, so I naturally blamed first the fan that was on, then the air conditioning, and finally the batteries. None of the above. It was the new cart's interaction with the gauge. I know this because I just swapped back to an old cart and the reading is stable and repeatable (as usual)--with the air and fan on.

I have no idea what about the cart's interaction with the gauge is causing the disturbance, but I share Actusreus's concern about getting a repeatable number in such circumstances (my fluctuations were far more wild than his, but even so). The reasons are for this concern are none of your business ;-)

Stringreen,
Whom are your comments directed at? No one challenged or took issue with your posts. It's puzzling to me why you would choose to post such an antagonizing reply, whomever you're referring to.

As a side note, please re-read my original post. I never asked for advice about tracking my cartridge. I simply asked a specific question about a digital scale. This whole "silly argument" began because some of the responses, I believe starting with yours, moved away from what was asked and began a whole other discussion that now has culminated in these unnecessary diatribes. I know you mean to provide beneficial advice to those who know less than you (and I personally have always valued your opinion), but I think it would serve us all better to simply address the questions asked only, or refrain from posting, rather than pontificate, however accurate it might be in your opinion.

Yuk...this "argument" is really getting silly. I offered my views because in MY experience, I found my posting to be absolutely accurate...but only for those who are looking for the very best their setup can bring to them. If that is not your goal zei gazundt. ( although its a puzzelment why you are on this forum)

I prefer the good old analog VTF gauge. I can see the counterweight and I know it works, but the scale shown on eBay intrigues me. I suggest for calibration purposes using a brand new shiny penny. The new pennies weigh 2.500 grams. That is close to the VTF values we all seek. Just get a new, untouched penny from the bank, don't touch it with fingers and get oils on it, or clean with alcohol first and see how accurate your gauge is with that.

Dear Doug,
Dougdeacon said :

Your assumption that, "Actus is experienced enough to know whether he needs to go plus or minus 1/100th of a gram", is belied by his own words. He clearly stated that he has no intention of doing so.

Where? Now you are the one making assumptions. Being experienced enough and acting upon it are 2 different things. He only states the obvious fact of being guided by the manufacturer's advice and he has been polite enough to admit to being "less golden eared than you", nothing more.

BTW I'm tracking mine at 1.759g - subject to tolerance of course. :o)
Kind regards....

Moonglum,

Your assumption that, "Actus is experienced enough to know whether he needs to go plus or minus 1/100th of a gram", is belied by his own words. He clearly stated that he has no intention of doing so. I often find it helpful to read what people actually say before making assumptions on their behalf.

By way of clarification, no one has been "heckled". Heckling involves gibes or challenges offered with the intent to disrupt, upset or goad. The intent of all comments on this thread has been educational. A debate of ideas and practices does not constitute heckling.

Thanks for your input,
Doug

Dear Doug & Stringreen,
There is an old saying that in order to prove that something doesn't work at 1.75g you must at least be allowed the dignity of trying it first without being heckled?

Since 1.75 is the central reference point, I'm sure once this has taken place, Actus is experienced enough to know whether he needs to go plus or minus 1/100th of a gram?
Kind regards....

Doug,
I very much appreciate your response. If I used too strong a language in my post, please accept my apologies as well.

Btw, I suspected that a sense of hearing so acute must be to a large degree genetic, not learned, even though I'm sure one can be trained and learn to listen for certain things as well. Thank you for sharing it.

My apologies if my post came across as patronizing. I did attempt (not so successfully) to acknowledge what you just said, that, "Many of us just want to set our system up and listen to music, not tweak it for every record."

The last bit of my post that you quoted spoke to that, "..we all have our own way of enjoying this silly hobby. It certainly won't do any harm to play at that downforce."

Bingo on the gift of sensitive hearing also being a curse. We have had to walk out of restaurants because the piped in music was insufferable. Fifty years ago my mother used to leave the room when certain popular vocalists came on the radio or TV. My father would happily listen while she was stuffing cotton in her ears. (I've heard those vocalists again recently, on those TV promo ads for oldies collections... Paul and I run and hide with my mom, lol.) We don't tweak because we want to, we tweak because we have to.

Again, my apologies for belaboring a point that was not what you were asking.

Jeez,so he wants to know that his VTF is deadnuts on 1.75 gr. ,nothing wrong with that! Someone is having a bad day,no need to take it out on Actusreus!

It's evident from several recent threads that Actusreus is not yet comfortable with trusting his ears and prefers the security of measurements, even measurements that don't necessarily correlate to optimal sonics. If he believes that every Lyra is so free of sample deviations that precisely 1.75g of downforce is optimal, well, Jonathon Carr himself would tell him otherwise but we all have our own way of enjoying this silly hobby. It certainly won't do any harm to play at that downforce. ;-)

Doug,
You're misinterpreting my posts, or perhaps I'm not expressing myself clearly enough. I don't recall ever stating that I don't trust my ears; what I do criticize, however, is the blank assertion that only adjusting by ear can result in optimal sound in an absolute sense. What you might find optimal might not be optimal for another. Especially since your taste in music is vastly different from many fellow audiophiles'.

I also find your statements about the Delos a bit ridiculous. Even more so since you don't own one. It actually was J. Carr who told me and every other Delos owner that the cartridge performs best at a VTF of 1.75 g, in plain English in the Delos' manual. It was designed that way. In fact, every Delos and Kleos owner seems to uniformly be of the opinion that they do sound best at 1.75 g, even in this thread. So I find your criticism a bit ignorant. And if you trust your ears so much, why do you even have a scale at all? And why use protractors at all? Just slap that bad boy on and adjust by listening.

I'm not going to make apologies or made feel embarrassed because I want to know whether I'm tracking at what one of the most accomplished cartridge designers in the world with a long-known religious attention to and focus on the quality of his product recommends, which happens to sound heavenly to me as well. Unlike you (and frankly most likely 90% of audiophiles out there), I cannot hear the changes in the sound at the level you can. I fully realize that you know way more than I do about analog, but you sometimes come off as rather patronizing, which is unnecessary. Especially regarding equipment you don't own or have no familiarity with.

I will always value your opinion, but perhaps you can consider that not everyone has the gift (or the curse) you and Paul have when responding to honest, even if naive, questions. Many of us just want to set our system up an listen to music, not tweak it for every record.

Sbrownnw...thanks for the link to that scale! You can buy several of these for the price of one of the other scales.

I'm going to order one and try it.

I used the less than $15 pocket scale from ebay. Very accurate. Nickel weighs out to 5.00g and my audio shop had a 5.01g weight for calibrating and the scale was dead on. Has a tare button and does US / metric. Also comes with an extra battery and case.

pocket scale - no affiliation

Definitely have had the same experience with those scales. For me, it was never the same reading twice. Total rip off. I use the Shure with my Delos and for me 1.75 (assuming the Shure is accurate) tracks and sounds the best.

One definitely needs to adjust by ear after initial setup. The value in having an accurate scale is one knowing your in the ballpark and two being able to return to a specific weight after removing a particular cartridge. If you don't change carts very often then it's not as necessary. I only have one arm now and several carts so once I have a certain cart dialed in I note the weight I had it at last for next time. This saves time dialing it in latter.

Pradeep,

A scale that resolves to .1g is okay. If it displays 1.7 then you're somewhere between 1.65000 and 1.74999... That's close enough to begin tweaking by ear. My scale resolves to .01g but I rarely pay attention to the second digit.

Stringreen,
It's evident from several recent threads that Actusreus is not yet comfortable with trusting his ears and prefers the security of measurements, even measurements that don't necessarily correlate to optimal sonics. If he believes that every Lyra is so free of sample deviations that precisely 1.75g of downforce is optimal, well, Jonathon Carr himself would tell him otherwise but we all have our own way of enjoying this silly hobby. It certainly won't do any harm to play at that downforce. ;-)

Actusreus,
I tried one of those scales and it was strongly affected by magnetics, so much so that I regard it as unfit for the purpose for which it is sold. Additionally, ANY scale that resolves to .01g or better will respond to the slightest changes in air currents. I can alter the reading on my scale (different brand, same resolution) by waving my hand over it. Try moving verrrrrry slowly... and hold your breath. Seriously.

You don't need a $250 scale, unless you insist on one with an audiophile logo. My My-Weigh MX-50 cost <$99. With the addition of a DIY weighing step it works just fine, certainly far better than the one you originally described.

I have also had poor experience with those generic scales that sell under various brand names. I now use a Ortofon scale approx SGD 130 or so. It has a lip that extends beyond the platter so you are measuring pretty close to the right spot. Only downside is that it doesn't go beyond 0.1gm.I am supposed to track my Lyra Atlas at 1.72gm. So I measure to 1.70gm and then fine tune by ear.
Have ordered a relatively inexpensive scale from dx.com. You need some kind of makeshift stand to get it level with the platter.Hopefully it will work
Cheers
Pradeep

Thanks for the input, guys. I will try unplugging and replacing the batteries. I agree with Phil that it's a shame quality digital scales sell for so much. In addition, the design of some of the expensive scales such as Clearaudio (Mapleshade seem to have the same design with a lip for placing the stylus at record level) is not very practical with the Classic platter (and I suspect many other platters) because of the slight "cutout" in the platter for the label. I tried the Clearaudio scale and it was very awkward to use as I had to angle it on the platter to have it stable and perfectly level. That in turn made placing the stylus on the lip quite tricky. $250 is a lot of money for a scale that needs five minutes of setting up to take a measurement.

I've actually had this happen before with a digital scale - probably the same one you are talking about that has the same cosemetic design as several sold by Acoustech, Audio Additives and Pro-ject among others.

Believe it or not, the darn thing would not only register weight as the cart apporached the scale, but would fluctuate in its readings by 0.1-0.2 grams each time I weighed the cart without change of the VTF.

I changed the batteries in the scale and presto - everything was fixed. I think if the batteries in the scale are not fully charged, you can start to see funny things happen to this scale. Wish there was a better digital scale that didn't cost $200 or more.

You might try to unplug the table from AC power and unplug the tonearm cable, (and ground wire) from your preamp/phono stage. This will isolate the table.

Seems to me that you are getting some type of an electrical interference from either the tonearm wires or the coils in the cartridge. See if this solves your problem. Worth a try.

It may just be the way that scale reflects the change of adding weight to the scale surface. I would say that as long as it provides an accurate reading once it locks onto a weight, go with it. By the way I have a Kleos and have it set to 1.75 and sounds great, I have tried 1.70 and 1.80 as indicated the extremes of the suggested range by Lyra and the 1.75 works fine. I agree with you that the suspension system employed by the Delos and Kleos make the VTF crucial to optimum performance. How ever some may dis-agree, you only yourself to please.

Actusreus, I'm using the Cartridge Man digital scale. It is expensive but very stable and accurate. I did not really want to pay that much for a good scale but got feed up with the Shure and the other cheap digital scale I had. Another good thing about the Cartridge Man scale is it has a rechargeable battery. You just plug it in overnight when its low on juice.

Actus..how do you know that your Delos tracks best at 1,75, EVERY cartridge I've set up is a bit different than the next one off of the assembly line. Also, if your arm is a bit high or a bit low to absolutely horizontal (who can tell when that occurs), it will affect the cartridge. Those setup guides are just that....use them to take you to a good place, and then use your ears to bring your cartridge to a great place. As far as the Shure scales being a bit off...Some are made of aluminum and are non attractive to the magnet in the cartridge, and some are made with something that does attract the magnet (not a good idea). You can get better accuracy by putting the Shure scale at the beginning of the platter, so that the front "feet" are off the platter (but use the non attractive version of the scale.

Peterayer,
The gauge is set to 0.00, but begins to show a negative reading as the tonearm is half-way down toward it, no matter how gently and carefully I lower it. At which point would you reset it? The platter is definitely level.

Stringreen,
The Delos is designed to perform best at 1.75 g. You can read about it on the Lyra site, but it essentially aligns the signal coils precisely parallel to the magnets during play. That's also what I've found. As far as the Shure, I have two of those and their readings were inconsistent so it was obvious that at least one of them was inaccurate. That was the reason I decided to get an electronic scale.

Slaw,
The gauge does not really fluctuate, and does settle down fine. It really appears to work well and provides consistent measurements. I don't think the negative reading is a defect; I think it's probably the result of the scale being very sensitive. It also looks well made.

I of course listen with my ears, but as I explained above, I should know what VTF I'm actually tracking at. I noticed that weather, prolonged non-use, and sometimes simply inexplicably, the setup gets re-adjusted. An accurate stylus gauge is just a basic necessity in our hobby.

Eddie,
The minus reading displays when the tonearm begins to move, not when the stylus is on the dot, or very close to it. So I think it's highly unlikely that it has anything to do with magnetization, but I suppose stranger things have happened...

My guess is the strength of the cartridge magnet is somehow affecting the scale accuracy. It reads ZERO until you place the cartridge over the scale then as it lowers the values start to flucuate.

That's my best guess!

Why do you want to track your Delos as close to 1.75 as possible? Maybe it sounds better a bit heavier or lighter...that's why I think the Shure scale is totally fine. You get it close with that, and then experiment by listening. I don't really care what my cartridge tracks at.

Is there a way to reset the value to 0.00? There is on my Micro-Tech XMT-200 electronic gauge. I also just checked it and if it is not level, it sometimes shows a negative reading.

I can't explain the reason for your problem, however I know and have experienced the same issue, as I'm sure countless others have here.
It seems like you're describing the guage marketed by many but manufactured by one, which I won't name.
My specimen would never 'settle' down. It would constantly fluctuate. It's a piece of trash.
Get a $80.00 Mapleshade, pretty damn accurate, uses AAA batteries, works great. Then, listen with your ears.