Do 45 RPM records need higher anti-skate setting?


I was playing one of my 45's today and heard Distinct mistracking on one channel only. I increased the skating setting and it was much better. This was only near he beginning of the LP. The LP was a Cannoball Adderly record. Do 45's require higher anti skate setting or is just a peculiarity of this record. The vinyl system is an LP12, Arkiv B and Ekos II, which invariably tracks very well.
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1. The difference in sound between 33 and 45 has nothing to do with the amount of energy being put into the stylus or the energy in the system. It has to do with less information density on the groove. There is greater length groove per second of musical signal. Lower information density, which is storing the same information in a greater storage area/length/volume (depending on the technology) gives greater fidelity. This is true in records, tape (30ips instead of 15ips, for instance), photography (a 4" x 5" negative compared to 35mm, which is 1" x 1.5", movie film....any analog medium.

This is a huge thing, and it is why more tape run by the head, more groove length under the stylus, and greater info on a negative enlarged to the same size all yield great improvements. The record does not play louder with a 45, which it would with higher modulation, the tape does not play louder.

2. As for energy, you are mixing energies. Energy put into moving the cantiliver is the same or volume would be louder. Kinetic energy of the platter is higher, yes, but that has nothing to do with playback and has nothing to do with more energy put into the cartridge, which is not done.

But, there is more kinetic energy in the platter. You are wondering about it. Well, where it came from is the energy put into it by the motor. That kinetic energy came from the torque required to get it up to speed over the period of time of acceleration. That energy is = i(w x w) where w (omega) = rotational velocity and i is the moment of the inertia of the platter. That energy stays constant, and when the switch is turned off the energy gets bled off, turning into heat, in the bearings and motor "off torque". That amount of energy during deceleration = the amount of acceleration = the kinetic energy while the platter was turning. Thus, energy is neither created nor destroyed, but is conserved, only changing forms. Newton is satisfied. Or at least his laws are, I trust he is dis-satisfied about how much physics is twisted and mutilated in this industry!

And finally, here is the bit of wrong information on the forum John sent us to, written by a "John" on that forum.

There is no centripetal force involved, as the arm is not rotating with the record. Now, if we put the whole turntable and tonearm mechanism on a rotating sub table and rotated the subtable then the cartridge would indeed try to fly outward.

But I know of nobody spinning their ENTIRE turntable setup while playing a record, so there is not such force.

It is a great optical illusion: stylus on a rotating record, so it must fly outward! False illusion. Spin the platter faster and faster and faster and there still is no centripetal force: only the platter is spinning! There can be no such force as the velocity of the stylus/cartridge/headshell in the tangential direction is essentially zero.

Don't worry about getting this wrong, most first year physics students would. A lifetime studying and working in physics and engineering: there's no substitute for that plus the education beforehand. Nobody should feel bad about that, I do not feel bad about not knowing as much about their respective fields as my doctor and lawyer do!
Timetel, please read my earlier entries on this thread where I explain the formula for skating force. Skating force remains the same since it is based solely on the magnitude of friction and the offset angle of the tonearm. Same tonearm, same friction, same skating force, so anti-skate should remain the same.



Here we go again: VTF cannot be different for each channel. Left wall and right wall are identical - how could they not be given that they are cut by a single cutter?! Each nudge, each bump, each movement of the inside groove wall is duplicated on the outside groove wall. This is the Westerex system.

Horizontal movement is L + R channels. Vertical movement is L - R channel. 45 degree orientation of coils give the sum and difference results of L and R.
Regards, Omsed: Let's clarify the difference between centrifugal and centripetal force. Centripetal force is ANY force that acts to prevent an object from moving away from the center of an orbit, see http://www.diffen.com/difference/Centrifugal_Force_vs_Centripetal_Force.

Consider skating phenomena the consequence of two forces acting upon the TA. First, friction along the axis of the TA. This is relative to grove modulation or any stylus "drag" in an unmodulated groove, or even an un-grooved disc.

Any TA (with under or overhang) will be subject to a second vector, this is tangent to the long axis of the TA, and, dependent on wether the stylus is under or overhung relative to the spindle, will exert a lateral force on the stylus. The TA will be inclined to move either away (underhung), or towards (overhang) the center of revolution. The groove constrains the TA movement and serves as a centripetal force.

These actions are observable and repeatable, the same principles that guided Sir Isaac, who also gave definition to centripetal force.

The question remains unanswered, would not a TA tend towards the center of an un-grooved disc more rapidly if spun at 45rpm rather than at 33.3rpm?

Peace,

Omsed,
No one is talking about spinning a complete turntable, or that there is a centripetal force involved in the skating issue, or that the cartridge is spinning with the record. If you read all the posts here and elsewhere I think that is clear. The only reason for using the term at all is in attempting to try and clarify the difference between a force acting toward the centre in the context of an arm being spun or a body in orbit, and a force acting towards the centre in a tonearm in reaction to the friction in the groove.

VTF is, of course, different on each groove face unless anti-skate is used. That's why the skating force is a problem. That is elementary. I don't get what you are saying re the groove faces being identical etc. We are not talking about record cutting, but playback.

Regarding information storage, if I store the same information in a bigger space, that's all I have done. When I retrieve it, I get it back. The point about the bigger space is that I can store more information, otherwise what's the point? Perhaps I am wrong, not being a recording engineer, but I was under the impression that higher speed allowed higher levels, whether it be tape or vinyl. And if there is more information, of whatever kind, the cartridge has to do more work to retrieve it, hence the reference, albeit imprecise, to energy (I take your point about the irrelevance of the platter's kinetic energy).

As you are having difficulty finding proper scientific papers, I've posted a link here. Look at Gilson and Alexandrovitch.

John
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