Stylus force digital scales

chakster

...  the problem with cheap digital scales and with mechanical scales is that all of them have different thickness, normally thicker than vinyl record, so they are incorrect, because the stylus is not leveled right.

Gravity is a constant. VTF doesn't change just because one record is thicker than another.

lewm

... gravity is a constant for any particular location on earth, however, actual VTF will vary depending upon where the tonearm is located in its vertical arc.  This happens when you play a warped LP, for example

Varying VTF while playing a warped record is the result of dynamic forces. What we're talking about here is static VTF, which does not "vary depending upon where the tonearm is located in its vertical arc."

Also, if you use a dynamically balanced arm, VTF will remain constant even while playing a warped record.

dover.

... Most dynamic balancing is applied with a spring which is designed to provide a restorative force to the arm. The actual tracking force at the stylus will be unpredictable and variable depending on the cartridge compliance, size and gradient of the warp and speed of the record. The competing forces are far more complex - it would be almost impossible to provide a constant tracking force over a record warp.

Provided that the phono cartridge and arm are properly matched, a dynamically balanced arm will provide precise VTF within a very narrow range even over a warp. There may be some deviation, but it will be slight compared to a statically balanced arm.

dover

I do agree that the deviation in VTF with dynamically balanced arms will be less than statically balanced arms on warps, but don't agree that VTF can be precisely maintained over a warp even with dynamic balancing, unless of course you consider +- 50% precise.

Don't be silly. The effectiveness of dynamic balancing in achieving relatively constant VTF over warps can easily be observed by watching the deflection of the cartridge cantilever.

A 50 percent deviation from ideal VTF would cause serious mistracking with many cartridges.

lewm09-26-2017 3:00pm

Cleeds,
Imagine that you are the stylus tip.  With the arm wand parallel to the LP surface, someone has set VTF for 1.5gm.  Now imagine that you encounter a record warp ...

I understand record warps and the dynamic nature of VTF. That's exactly why I mentioned the differences between statically balanced and dynamically balanced pickup arms.

Imagine that the tonearm has unlimited travel in the vertical plane.  It could then point straight up at the ceiling. What would be the VTF in that case? Zero.

That's absurd, because a pickup arm would never be vertical. The truth is that static VTF - within any normal range of a pickup arm - is not influenced by the thickness of a record.

Do you weigh more when you lie down or stand up?

lewm

You don’t understand. And you don’t want to understand. So why bother? ... Or simply do the experiment I suggested: Measure or set VTF with the tonearm parallel to the surface of an LP. Then place a couple of spacers under your digital scale ... measure VTF again ... Don’t come back at me until you’ve done this ...

Pardon me, but I’m not obligated to complete your homework assignment as a prerequisite to posting here. I’m sorry if that troubles you.

You seem to enjoy engaging in hair-splitting "thought experiments." You’ll have to accept that such exercises as imagining that I’m a phono stylus don’t interest me.

Two things you either don’t understand, or don’t want to understand:

1. The thickness of an LP has a trivial effect on VTF. Unless you’re playing discs that are an inch thick, the variation in static VTF between the thinnest Dynagroove LP and the thickest MoFi (or whatever) remaster is trivial. And yes, I’ve confirmed this with an accurate digital scale.

2.) Dynamic VTF - which is influenced by such factors as record warp - is nowhere near the absurd plus-or-minus 50 percent range you’ve claimed, provided that the pickup arm and phono cartridge are properly matched and calibrated. In addition, the use of a dynamically balanced pickup arm will greatly reduced the degree of VTF deviation and, as I’ve previously explained, this can easily be confirmed by observing the phono cartridge’s cantilever deflection as it navigates a warp.

Further, to be clear, the actual sonic benefit of using dynamic balance in a pickup arm is hotly debated, with many arguing that a statically balanced arm delivers better performance. Without taking a side on the debate, it’s clear that the enduring debate itself suggests that the consequences of a cartridge’s varying VTF as it navigates an LP is nowhere near as critical as you would seem to suggest - again, provided the system has been properly matched and calibrated from the outset.

Some users of dynamically balanced pickup arms such as the SME V apply VTF by using equal amounts of static and dynamic force. You might want to try it sometime, if that’s an option for you.