XV-1S and Antiskate
On a grooveless record the POINT of the stylus rides on a flat, unmodulated surface. The contact surfaces don't touch anything. When you listen to music the SIDES of the stylus ride on a pair of opposed, modulated walls. The point never touches anything. These are two quite different conditions. Extrapolating from one to the other is fraught with untested assumptions. By analogy, you tested Z-rated tires on a warm, dry track, found them to perform well at a certain psi, then extrapolated that psi to winter tires for driving in snow or off-road tires for driving in mud or sand. Experienced drivers know better. Skating forces do exist. They can be approximately compensated for with anti-skating. I say "approximately" because on real records the amount of skating force is ever-changing. The question becomes, how much (if any) anti-skating to use for real records? There's no simple or perfect answer and there are several factors to consider. Here are some: 1. Anti-skating may extend the life of a stylus. OTOH, cartridges with modern stylus profiles like the XV-1S tend to wear out their suspensions before their styli. When you have that rebuilt you'll get a new cantilever-stylus anyway. (Actually, the XV-1S tends to have its full monty cantilever snapped off before ANYTHING wears out. Of course playing with an unprotected stick is another issue.) 2. Anti-skating stresses a suspension, so one could argue that it further shortens the most short-lived part of the cartridge. Hah! 3. Anti-skating impairs sonics. You said the sound doesn't change that much, but then rather vaguely said anti-skating makes it "warmer". It changes the sound in my system and I hear very specific things. As with any form of dampening, pre-pressuring the cantilever against the suspension attenuates HF's, slows rise times and reduces amplitudes. This could be called "warmer", I call it dulled and lifeless. Like Audiofeil, I've heard this with the XV-1S and other top level cartridges, including several of my own. 4. My amp and preamp builder, Nick Doshi, states as one of his core design principles, "allow as few gain blocks as possible". If you've never heard one of his units you may not appreciate the significance, but I do. Anti-skating is a gain block. It inhibits cantilever movement in exactly the same way that excessive VTF does. There's no right or wrong (other than using grooveless records to adjust parameters for playing grooved ones) but FWIW I bought my system to play music and choose to adjust it for optimal sonics. If this slightly reduces some component's lifetime, oh well. An occasional Shiraz or single malt may effect my component lifetime too, that's a tradeoff I'm willing to make. Of course there are risks I won't take, regardless of the excitement, but we'd have to discuss those on another forum. ;-) Doug P.S. While experimenting with lower and lower amounts of anti-skating I actually went through a period of tweaking it for each LP. The differences in tracking performance and sonics from very tiny changes were quite audible. I now use none because my main cartridge no longer needs it to track even the toughest passages. P.P.S. As I no longer use anti-skating, I removed the device from my (TriPlanar) tonearm altogether. This had a small but beneficial effect in lowering the arm's noise floor. The fewer twiddly bits to vibrate and put noise into an arm, the better. |
Thanks Doug for the comprehensive answer and you bring some clarity to this issue. I know the XV-1s is a fantastic tracker so much so that I thought it might hiding the need for more anti skate. The grooveless record test just suggested that some antiskate was required. What I didn't know was how strong the XV-1s is as you suggest. Wouldn't want to snap off the cantilever just to see how strong it is :-) Would you consider the damping fluid in the Phantom to be a "Gain block"? I am finding some damping fluid is required to tame the high frequencies on the XV-1s otherwise the top end can be bright and brittle on some records. John |
I agree with Doug that the grooveless LP is useless for setting anti-skate, but apart from that, lets admit that skating force is a result of the offset angle of the headshell on a pivoted tonearm plus the frictional forces generated as a stylus traces a groove. Ergo, no combination of cartridge and pivoted tonearm cum offset headshell is exempt from skating force, no matter how wonderful or expensive the cartridge and tonearm may be. So the choice not to use any anti-skating is simply a choice based on how you like your sound; it is not an indication that skating force is absent. Doug, How is anti-skating equivalent to a gain block? I think Nick Dolshi must be referring to active devices in the signal path that add gain. So....? |
I tried nearly every setting from AS to no AS. Yes, no AS is definitely different, but in my opinion only "better in the first minute". I am back with AS, but as little as possible in combination with looking what movement the needle is going to do. When Antiskate is done wrong (too high), you won't do yourself a favor. Antiskate Such a result will never happen, when you don't use any AS at all. This cartridge is destroyed completely based on wrong AS. Graham Phantom Bearing fluid In a way it is a bit dependent on the overall performance of your System. IMO it is best, when only the bearing tip is in the fluid. when it is too high, the Sound will get slow, anemic. the problem is, when you do the cross check at one, the result is not final. The fluid is cold and needs some time to go down. When you make it warm, it is better for comparisons. Based on this Temperature issue I used bearing oil instead of the original fluid. |
Musichead, I heard an XV-1S cantilever snap from across the room once. The owner was aligning the cart and had one brief moment of inattention. Be careful, it can be done without really trying. Agree with Lewm and Syntax that the decision of how much anti-skating to use, if any, must balance sonics vs. the desire to counteract this unavoidable force. Definitely a YMMV, there is no perfect or correct answer. *** As to Lewm's question about gain blocks, Nick didn't limit his principle to "active devices in the signal path" and I doubt he'd agree to. A poor quality capacitor or resistor will act as a gain block, though it's not active. A crappy power supply will act as a gain block, though it's technically not in the signal path. I wouldn't accept either of these proposed limitations. Even if we did, I could argue that a cantilever is an active (or at least kinetic) device. It's powered by groove modulations rather than electricity, but if we somehow prevented it from moving there would be zero signal. It's certainly in the signal path, that's clear. There's nothing else between groove modulations and generator and if we removed the cantilever there would be zero signal. It's not just in the signal path, it IS the signal path. So, think about what happens INSIDE a cartridge when we apply an external lateral (or vertical) pressure to the tonearm: the cantilever (signal path) is artificially pressured against the elastomers in the suspension. Press any vibrating rod into any elastomer and what happens to the vibrations? 1. Rise times are slowed, always. 2. Amplitudes are attenuated, always. The exact effects will vary with frequency and with the materials involved, but this is as clear and direct an example of a gain block as I can imagine, and it's precisely what excessive anti-skating AND excessive VTF do. FWIW and IME, some cartridges that eventually play well with no A/S do need a little when new. The suspension may need to relax before the cart can track tough passages without a touch of A/S. *** I wouldn't regard a Graham's damping fluid as a gain block. It's more like an out-of-signal-path resonance filter. Using too much does sound exactly as Syntax described on a 2.2. *** Excessive A/S can do what Syntax's scary photo showed. Low or zero A/S can never do that under any circumstances. |
I found that the proper way to set anti-skate on my TT is by ear. Start out way low on the anti skate, after you have the cartridge alignment and VTA and tracking force dialed in. This is the last step. Listen to the dynamics of a piece od music you know well, use something that has some continual dynamic, like an uptempo drum and cymbal, as well as voice; specially the right channel. Then slowly raise the anti-skate a bit at a time and reassess. Go slowly and only move a little bit at a time. You should hear the dynamics in the right channel come up slowly as the anti-skate increases, then eventually both channels will begin to improve. Keep going a wee bit at a time and you will hear the dynamics and quality fall off pretty suddenly. Back it up a bit until they come back and ... there you go. It is very apparent that the sound quality changes as the anti-skate amount changes. There is an apparent "best" place, which could vary from one setup to another and not necissarily coincide with a manufacturer's recommendations. |
Doug, Thanks for the explanation, but by that loose definition, what is NOT a gain block? Only straight wire, most likely. But then, wire also affects sound. In the parlance I am used to, the term "gain block" would be interchangeable with "gain stage" and nothing else. Anyway, as the late great Gilda Radner once said (as Emily Latella on SNL), "Never mind". In my system, with both the Triplanar and a Dynavector DV505 tonearms and any of my many MC and MM cartridges, no AS results in a R channel bias and some low level distortions that are cured by a minimal amount of AS. I start with zero and add teeny amounts until the problem is cured. I have you and others to thank for the concept that a minimum amount is best, but I cannot get away with none, so far. |
Doug: In most MC cartridges, the coil former and coils are located at the rear end of the cantilever, and are always being pressed into the dampers. Since the amount of pressure affects things like tracking and frequency response, it is the cartridge builder who sets the net pressure (during the building and adjustment process), and the pressure adjustment is locked down by screws so that the value cannot be reduced (or increased) inadvertently. If it does become reduced, chances are that the cartridge will ride too close to the LP surface (low-rider). Due to the constant pressure between coils and dampers, "slower rise times" and "attenuated amplitudes" simply describe how most MC cartridges work normally. These are not issues that suddenly appear because the user happens to choose antiskating or VTF values that are higher than optimal. What excess antiskating can do is cause uneven loading of the stylus profile within the LP groove, angular misalignment of the coil former and imbalances in the forces that act on the same. The antiskating effects manifest themselves in the horizontal plane. Doug, I agree with you that improper VTF is conceptually similar to improper anti-skating. What's different is that, unlike AS, we need a minimum level of VTF to ensure adequate physical tracking of the groove (but uneven stylus loading in the LP groove is no longer an issue). And since VTF forces are typically 5-10 time higher than AS, compared to AS we get a far greater degree of angular misalignment of the coil former and imbalances in the forces that act on the same. And, it is in the vertical plane that we see the effects. As problems to be solved, AS is far more intractable than VTF. VTF requirements don't change across the LP, so it is possible to understand in advance what value works best and specify this (although changes in ambient temperature and humidity may require some readjustments). In contrast, AS requirements change according to the LP groove radius and groove drag (caused by groove modulation and stylus profile). It is possible to solve the groove radius issue, but the groove drag issue is more doubtful, unless you are using a linear tracking arm or some kind of electronic servo arm. I suggest that it is much easier to speak of a "right" and "wrong" VTF setting than AS. cheers, jonathan |
Very interesting. After living with a VPI HRX for quite a few years, antiskating was not really offered, except for the wire twist, which always sounded worse. VPI has always copped a lot of criticism for this approach with pundits/experts stating that no AS will cause cantilever alignment issues. Now, some on this thread intimate that AS will cause cantilever alignment issues. I assume this is when it is higher than the VTF? Does AS coninciding with the recommended VTF cause cantilever issues? So has Harry Weisfeld been correct all along that the best AS is no AS ? I must admit I use antiskate now,as my tonearms have it. I may play around with less than receommended level's now cheers |
Lew, With some (many?) cartridges you may never get away with zero A/S. IME it's quite cartridge-specific. We've heard variations between multiple samples of the same model. Paul believes this is due to sample variability in the behavior of elastomers. Each cartridge must be tuned individually for optimal behavior (sonics). *** Jonathon, Thanks as always for a truly informative post. To be clear, my description of "slower rise times" and "attenuated amplitudes" wasn't a deduction from principles. It's what we actually hear. Of course I'm open to explanations other than cantilever damping, but they'd have to account for these observed phenomena. While it's true that the cantilever is pre-loaded against the suspension by the cartridge manufacturer, when the user increases the amount of pre-loading he alters the behavior of the system. This is true in any spring-loaded system. Example: like most off-road vehicles, my Land Rover has a long travel suspension. When driving by myself, my massive 140 lbs. don't add much to the 4,000 lbs that the manufacturer pre-loaded on the springs. Result? The vehicle rides high on the springs, over certain bumps it's a bit jouncy ("lively" or even "edgy" in audiophile terms). Now add three 200 pound passengers and a pile of gear. What happens? The springs are compressed toward the middle of their range, the vehicle's rise times are slowed, it's amplitudes reduced (it rides "warmer", in the OP's parlance). Spring-loaded systems vary their behavior not just between pre-loaded or not pre-loaded, but also with the amount of pre-loading. Few elastomers respond linearly to compression. I just can't think of a better explanation of why we hear "slower rise times" and "attenuated amplitudes"... *** Downunder, When I first posted about removing my A/S device (on "TriPlanar Tips"), I remember joking about HW being right all along. :-) |
Hi Doug, all: A bit more explanation on damping inside the cartridge. There is a significant difference between the damping that the cartridge builder applies, and the damping that the user applies during normal playback (including VTF and AS). Please allow me refer to the following drawing. Sorry for using one of my drawings, but I want to illustrate the difference between pivoted vs linear damper compression, which most drawings don't do. (The same drawing is on our website, but it's a little small and therefore suspension and damper details are hard to see) http://www.evmag.fr/site.php?page=news97 When the cartridge craftsman adjusts the damper(s) during the building process, he moves the cantilever assembly longitudinally back and forth until he achieves the appropriate amount of damper compression (and therefore damping characteristics). The suspension wire fits into a larger rod (called the stopper pipe), and this stopper can move back and forth inside a matching tunnel which is drilled into either the magnet (in the case of yokeless designs) or the rear/center polepiece (in the case of conventional designs). The tunnel is drilled so that it is parallel to the stopper pipe (therefore perpendicular to the length axis of the rear polepiece). Usually, the polepiece is fitted with a grub screw to enable the craftsman to lock the stopper pipe in place once the desired damping point has been reached. The damper(s) are sandwiched and compressed between the coil former and rear polepiece, and it is the degree of compression that defines the total damping amount. Since the stopper pipe can only move longitudinally within the matching tunnel, you can visualize that, when the cartridge craftsman adjusts the damping, the dampers are compressed evenly across their entire surface. IOW, when the cartridge craftsman adjust the dampers, the total amount of damper compression and therefore damping changes substantially. However, damping that the user applies via VTF and AS during normal playback is a different issue. Again if you refer to my cartridge cross-section drawing, you may note that, when VTF is applied to a conventional cartridge, the cantilever and coil former appear to be angled in comparison to the rear polepiece. This is because the cantilever and coil former are rotating around a pivot point. The suspension wire is enclosed along nearly its entire length - inside the solidness of the cantilever at the front, and within the (again solid) stopper pipe at the rear. The only place where the suspension wire is unenclosed is a very short length either inside the coil former or right behind it. This place is called the suspension pivot point, and here and here only the suspension wire is free to move. When the user applies VTF and AS during normal playback, the coil former rotates around the suspension pivot point, altering the distribution of compression on the damper(s) sandwiched between the former and rear polepiece. But since the movement of the coil former is rotary rather than longitudinal, when one section of the damper(s) is more heavily compressed, the section 180 degrees across it will be unloaded by the same amount. The relation is like a see-saw - when one side of the damper become more compressed because the cantilever is forcing the coil former more heavily into it, the other side of the damper becomes less heavily loaded. The total amount of damper compression doesn't change, because any increase in damper compression on one side is counteracted by less compression on the other. Your analogy with the Land Rover (nice car!) is different than an MC cartridge, because with cars the damper and suspension preloading incorporated by the manufacturer occurs in the same axis as the loading applied by the user. With MC cartridges the damper suspension preloading incorporated by the manufacturer is longitudinal and therefore affects the total amount of damping, while the loading applied by the user occurs in the form of rotation (see-saw), and total changes in damper compression will be far less. However, Doug, none of the above means that I am critiquing your post. After accounting for the above explanation, we are left with a couple of residual effects which may help to explain why we hear changes with VTF and AS (and I concur that we do). These would include progressive or non-linear characteristics of the damper(s), mis-orientation of the coils, and motional non-linearities due to mis-orientation of the coil former (although the last factor should only affect permeable rather than non-permeable formers). kind regards, jonathan |
