How to properly set VTF??

After pondering some of these excellent responses,Bob's really puts the "Kabbash" on anyone using an arm with antiskate.Possibly!

Maybe this is one reason Harry Weissfeld,of VPI does not employ an antiskate setting on his unipivots.

This does seem to lend creedence to the issue of a "tangenital tracking" arm.Like the Air Tangent/Kuzma Airline/or Walker!

In reality I guess the best I can do,in my own set-up,is "guesstimate"!!

However, just to continue the discussion, if we assume that on a given listening session all things being equal (humidity, temp, phase of the moon, etc.) that these variances that Bob mentions across the record will be pretty much the same each time the record is played. (I would hope they are or there is something really wrong with all of our playback equipment.) In this case the VTF of 1.87 is the only parameter we can measure to somewhat predict the behavior of the arm/cartridge across the grooves. Perhaps with some arms and some cartridges it can make a difference. (I admit I haven't experienced it but I don't yet own a cartridge that could respond to that level of adjustment. Mine don't even respond much to VTA changes. :) ) I can't help but draw an analogy to a stock car. The suspension, and thus the load on any tire, is constantly changing all the way around the track but the only way to somehow predict the behavior is to weigh the static load on each tire. Then changes are made during the run to compesate for what is actually happening. We have the advantage in that our "track", the grooves, are much more predictable in that we don't have to worry about what line we trace since there is only one.

Sirspeedy, the reason that AS is not a good idea with uni-pivot arms is that the horizontal vector imposed at the stylus will cause a unipivot to twist and drive the stylus out of azymuth (and also lower the VTF, due to the upward vector imposed by the torque)since there is no bearing in that horizontal plan to counteract that force. My STAX UA7 was a unipivot arm, which had a very elaborate AS (variable across the disc), but I ended up using very little AS, as determined by listening with a test record.
Dan_ed, if every record were recorded at the same level (level and frequency affect the friction which causes the centripedial force, along with the VTF and the 'lack of tangency'), were of the same length and thickness, then yes I would say that extreme accuracy on the VTF would be worth it. However, as you have mentioned, one cannot get 0.01g repeatability reliably from the VTF mechanisms on todays arms. Even those that claim to dial in the 1.87g and play, will tell you that after they carefully and painstakingly set the VTF to 0.01 precision, they then reset the VTF according to ear.
Might as well set the VTF to 1.9g (with less fuss) and then tune the VTF. It is quicker and just as good, depending on your ears, of course.
Bob P.

Though good points by Dan and Bob,the fact is that I want to enjoy my vinyl with the feeling of being as close to the "zone" as possible.No need to get as technical as Bob(though technically right).In our setting up(to max)my friend's arm/cartridge,we used the Winds guage,which is sensitive to 1/100's gm,as I've stated previously.We found the correct combo of vta/damping fluid(2.2 arm)and a reasonably close downforce,that we all agreed was in the "very close to ideal" zone.We did this over numerous listening sessions at my pal's home.

Dan,if you have a hard time differentiating between vta settings,I think something may be amiss!Any change of vta/downforce/fluid is clearly heard in my friend's set-up(as in my own).We settled in on 1.87 gms(for my friend)after zoning close to it,using all settings(1/100 gm increments)starting at the min recommendation,and ending at the max mfgr recommendation.We literally played around for an endless variety before settling in on the 1.87.

Here's how we settled,in finality.----My friend Sid is an extremely experienced audio buff/music maven(of the highest degree).We play a series of discs that we are familiar with,but Sid gets final approval of ultimate performance,as he has his own set of discs we also use.Fortunately he has actually been to some of these recording sessions,so when he states that Pavarotti's voice needs to be fleshed out a bit more (even though it seems fine to me),I adjust arm/cart to his ultimate preferrence.Truthfully the guy has the best sense of musical perception(as opposed to just great ears)that I've ever experienced!

When he likes the way voices sound,as well as complex orchestral tracking,we lock all in.We do use populr music too,but the hard stuff is complex orchestral music,as the cantilever "hates" to track this stuff!!This is how we wound up at 1.87.Which may not actually be 1.87,based on the technical input previously,but it's "THE 1.87" to us!

Now we have a benchmark that my pal can set his downforce to,with a good digital guage.Vta is locked,as is the fluid level,so unless environmental conditions change,alot,he's in good shape to finally get consistent vinyl sound.

I hope this makes sense,as nothing should be set in stone,but I want to simplify my own time involved in dialing in settings,and don't care if my 1.87 is not really 1.87 at some points of playback,as long as the quality of sound is good,and is repeatable at this particular designation.

I mean if we wanted to get really technical,we could argue the drift differences in "spirit levels".Which all vary,in the collection I've got.Who knows if we are actually perfectly parallel,on all planes.This makes an audible diff too!Just a thought,to ponder.

Best regards!

Bob, I agree with most of what you're saying. However I do believe that arms such as the 2.2 is it possible to get repeatable VTF settings provided the scale used is good enough which is what SirSpeedy is telling us. I am betting that I could do this with my RB-250 that has a Mitchell weight installed with the micrometer-like VTF adjustment. But first I would need to invest in the $800 Winds (OUCH!). If we're talking about a Vector, or TriPlanar, or perhaps your Stax (I'm not familiar with the VTF machanism on that arm) I will agree completely with you as it is damn near impossible to move the weight in such small adjustments on these arms. All this being said, I think we do all agree that getting it really close with the guage and then adjusting by ear is the way to go.

SirSpeedy, I've only played extensively with a 103R and a Benz Glider. Both of which do no seem to react much to VTA over a fairly wide range. This used to drive me crazy because here I am trying to listen for changes and they just never happened on both the Vector and 2.2. I've since learned from others that these two cartridges are not real sensitive to VTA and I guess I've proven that to myself.