Tracking Force Scales Accuracy

[Jimbo]

Hi Rob, If you have some scales and you want me to check if they are weighing accurately I can compare them against a scientific balance I use at work which is calibrated regularly and weighs to 4 decimal points.

[Cas]

got one of these to try against my usual similar to one you pointed to. accurecy is very similar. this one is prettier and has a bigger target area. its really a jewellery scale
https://www.ebay.co.uk/itm/Gold-200g...item2ac10d11cd

That's a nice looking scale as long as it does the job, nice price as well

[RobbieGong]

Hi Rob, If you have some scales and you want me to check if they are weighing accurately I can compare them against a scientific balance I use at work which is calibrated regularly and weighs to 4 decimal points.

Thanks for the kind offer Jimbo,

I'll remember that if I decide to take you up on it - top man

[blake]

Really? That's about the weight of a grain of sand. So are you adjusting the VTF for every LP you play as the variation in the thickness of an LP will give you more of a variation in VTF than 0.02g? Also, unless every LP you have is super flat then you will get more than 0.02 variation in VTF as the record plays.

Actually, variation in thickness of LP or warps will result in very little variation in VTF once set unless you are using a unipivot or an arm with a very low slung counterweight (neither of which I use) playing reasonably flat records. If you have records with 5-8 mm warps that might be a different story but I don't have any of those in my collection.

I don't adjust VTF for every LP. That is, of course, a compromise and I'm ok with that. But if optimal "compromised" sound is off because of .02-.03 VTF being high or low and I can correct that I will. That type of range has created audible differences with a number of cartridges I've used in my system including modified Denon 103R's (ebony and aluminum bodies with line contact styli on ruby cantilevers), a couple of retipped MC 20 Supers and the current Accuphase AC 2 that I use.

Jonathan Carr of Lyra takes it a step further actually; he suggests that ideal VTF for certain Lyra cartridges will be in an extremely tight range, within .01 grams, slightly varying from sample to sample.

I would say that I'd be hard pressed to identify differences in sound quality within a range like that, but at .025-.035 grams not so much. There's not much question in my mind that differences of .05 grams are pretty significant with a good cartridge in a resolving system.

But yes, I figured I would receive a response like this.

[blake]

Hello Blake,

I found it very interesting that you think you can hear differences in sound with changes of 0.01grams. What do you think is the reason for this? Do you think it might be that you are on the edge of the weight you Jelco arm can take with you Headshell and cartridge combo, so that slightly changes in weight emphasise the bass or result in resonance issues?

I don't think so as I've experienced the same thing (as outlined above) with a few different cartridges with different compliances. The Denons had lower compliance than either my Ortofons or Accuphase (both of which have essentially the same compliance) and the audible differences have been similar with all 3 cartridges. I've always used the fluid damping on my 750 as well.

To clarify, the range I suggested was .02-.03 grams not .01 grams. That's running it awfully close and I'm sure that I'd have trouble identifying differences within that kind of range. But .04-.05 grams will be very significant with a lot of decent cartridges. That is the advantage of having a good digital scale-it can repeatedly get you into a setting within a range like that.

You do want to be careful with jewellers scales (even the Canrongs have a platform that is slightly above real record height) in terms of the height of the platform. Many of them have very thick platforms and if you do have a unipivot or arm with an underslung counterweight, they will give you an over read on VTF with arms like that of as much as .3 grams if the platform is 4-5 mm above actual record height, more if it is higher.