dogberry, How do you know that you are setting AS to "half of VTF"? You can know the VTF in grams very precisely, but how do you know the AS force at the headshell, where the skating force is manifested? For me, that is where we are blinded unless Mijostyn will loan us his home made tool or we buy the Wally version.
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Raul, I am very surprised by your opinion. I am also surprised that you have the hubris to suggest that my hearing R channel distortion in the absence of AS in my system is evidence that something is wrong with my ears or my system. Whereas theory predicts one WOULD hear R channel distortion in the absence of AS. You can’t have it both ways; either you’re a purist who advocates that tubes and conical styli and anything else that either limits bandwidth or adds a distortion you can mrasure, should go, or you’re a subjectivist who says if it sounds good, it is good. You’ve heaped criticism upon those who take the latter position in the past, very consistently. I have generally found that a very tiny amount of AS, usually much less than textbook, suffices to alleviate the distortion, and that’s where I stop, but not at zero AS.
You might also add with what tonearm and cartridge do you draw your conclusions regarding AS.
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Let’s be clear on one issue: for all pivoted tonearms where the stylus overhangs the spindle, there IS a skating force at all times during play. So AS is not something you can choose not to believe in. The ways in which AS is created in different designs are all faulty, it’s fair to say, for reasons that have been mentioned, including the fact that skating force is applied at the stylus tip, whereas in all cases I know about AS is applied at or near the pivot. This puts a twisting force on the cantilever. Thus very short or more vertically oriented cantilevers might be advantageous. For those who say they can hear no difference with vs without AS, I have to wonder whether the tonearm has significant horizontal friction (or stiff wiring) that is acting to provide AS, because I can easily hear R channel distortion in the total absence of AS.
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Problem with magnetic: the magnitude of the force changes linearly with distance between the magnet and its ferrous target, as the tonearm rotates in the horizontal plane. But The skating force is not linear in the way its magnitude varies. In that respect Magnetic AS might be inferior to a weight on a string, at least the latter is more or less constant with respect to the magnitude of the AS force. Just a thought.
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fsonic, Ordinarily, I would totally agree with you. You are very correct to ask for scientific evidence to support any of the claims made regarding audio as a hobby, especially vinyl. There are so many erroneous but commonly held beliefs that persist just because of hearsay. BUT in this case, the weight of the circumstantial evidence in favor of using at least some anti-skate with a pivoted tonearm is SO overwhelming as to be convincing, at least good enough for me. Yes, the magnitude of AS required to fully compensate for the skating force at any moment in time on one LP vs another is not close to being a constant. That does not mean there is no benefit. Likewise, there probably is a negative consequence of using too much AS. Such is life.
But are you also protesting the crude nature of most AS devices on most tonearms? You ought to see the AS device on my Kenwood L07J tonearm, the arm that is an integral part of the Kenwood L07D TT, wouldn’t work on any other turntable but was given its own model name by Kenwood. It uses a nylon monofilament, but there is no dangling weight. The force is applied from the left side of the arm pillar (between pivot and spindle) but wraps around to the rear of the bearing pillar so as to pull the bearing housing forward (toward the front of the TT), therefore applying a force that rotates the pivot counter-clockwise, so the arm is pulled away from the spindle. The AS force is supplied by a weight that rides on a strut; the monofilament wraps around the bottom of the strut, riding on pulleys. The magnitude of the AS is adjusted by moving the weight with respect to the pivot point of the strut on which it rides. Thus no dangling weight.
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Hasn’t Peter Ledermann testified to the uneven wear on styli he has inspected personally, due to radically incorrect AS? So there’s your evidence, presented by an expert witness. (I agree with you that there’s no such thing as a perfect amount of AS, but you’d like to be in the ballpark.)
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The RS-A1 and the new Nottingham tonearm on the 294 model do not have anti-skate, because the headshell (and therefore the cartridge) is not set at an angle to the arm tube. Thus skating force is not generated. I think there are other older tonearms that are so designed. Perhaps yours is one of those. |
Bob P., The headshell on the RS-A1 tonearm has a unipivot bearing right at its base,in addition to the one at its main pivot point (so there are two articulations). Thus in theory the cartridge CAN always maintain tangency to the groove, and no skating force is generated. However, you are probably correct in general. (I've got to think about this a bit longer, and it does seem to me I've read in two other sources that skating force is generated by the offset headshell in 99.9% of all modern tonearms.) |
Audiofeil and Bob, You are both correct, as I already conceded to Bob. BUT since the headshell of the RS-A1 could in theory remain tangent to the groove at all points on the record, the designer claims that no skating force is generated. I would agree with you if you were to respond that the arm probably does not accomplish that goal perfectly in fact, due to friction in the bearings, etc. Now, as for a headshell that is not offset, there WILL be one point on the record where skating force does approach zero, but only one point. And Audiofeil, according to the references I read, the skating force is not due to "centripetal force" per se; it is due to the force of stylus drag (Fsd)and is equal to (Fsd X sin of the angle from tangent). So, when the angle from tangent is zero, the sin of the angle equals zero, and skating force disappears. I am very sorry for placing incorrect info on this thread in my previous post. |
