The last possibility that I can think of why the cartridge might sound better without AS is tonearm geometry set-up. We must use our protractors to set the HTA and VTA in a static situation. That means that while the cantilever is loaded in the vertical direction (VTF) it is not loaded in the horizontal direction. That slight difference could be audible to some. Quite true, it's certainly audible to me. Any change in horizontal loading produces a change in SRA. That's one parameter that I (and some others on this thread) adjust for every LP we play. Perhaps some tweaking is required to compensate. When I am setting up my tonearm position, I pull on the platter to load the stylus in the horizontal direction as I position the tonearm. Exactly right, though it's tricky to do accurately if using a high resolution protractor like the Mint. |
Excellent post Tony...I'm thinking of another possibility for variances in behaviour.
The same mechanism that VPI often use for antiskate - twisting of the arm cable - may have been unintentionally applied by manufacturers (or indeed by DIY owners) of other tonearms during arm cable-forming.
This could generate either a counter-force or worse, a complementary force?
I'm suspicious of the VPI solution as I can see it causing stress related micro-vibration in much the same way as clamping vinyl. But this is only an opinion....
Best regards, |
I owned the Sony PUA 237 some 30 years (?) ago but still
remember this peculiar 'bias compensator'. To refresh
my memory better I checked by the Vinylengine. Just one
quote from the user manual reg. 'bias compensator': 'In
conventional method ,M' is applied as a constant force. Therefore ,the side thrust is canceled out at ONLY few positions on the record.'
Regards, |
Ok the entire record is going at 33.3 but the outer grooves do cover a longer distance each revolution. So the platter is traveling faster on the outer grooves. But the same amount of information is contained in one revolution on the inner and outer grooves. So there is more packed into a smaller space on the inner grooves. So antiskate would be the same. Thats my best guess anyway. |
Hi all - Antiskate -
"In most turntables, as a result of the angle between the line tangent to the record grooves and a line connecting the stylus tip to the tone arm pivot point, a skating force is developed that tends to force the tone arm towards the center of the record. This skating force is proportional to the above described angle, the tracking force applied to the stylus and the coefficient of friction between the stylus and the record groove. Since the angle is constant for a given turntable and the coefficient of friction is approximately constant for a given stylus, the skating force is then equal to some constant multiplied by the tracking force applied to the stylus."
From the patent on an anti-skating device by Pickering.
This suggests that the anti-skate force required should be constant across the record.. |
Remember, the skating force is generated by the torque between the stylus and pivot in the horizontal direction acting on the tonearm. This torque comes from the friction between the stylus and the vinyl. It is sliding friction and as far as I know, the magnitude of this sliding friction does not change with respect to groove speed- at least in the range of the beginning to end of the record. It's not like the needle is being pulled through water where viscous drag would be speed dependent. It is more like a skidding car. The skidding friction is constant as the car decelerates and until the car comes to a stop. |
The record is spinning at a constant speed but the linear velocity at the inner grooves is about 50% slower than the outer grooves.
Velocity is defined as the change in distance divided by the change in time. The stylus covers a much smaller distance (remember the record is making one rotation every 1.8 seconds) in one revolution at the end of the record as compared to the beginning of the record. |
Nandric,
The spirals get smaller but the speed is the same everywhere on the platter. The only thing that should make a difference is the angle of the stylus as it crosses the record surface. Although I am no expert either, I am a building engineer. |
Tonywinsc, This is not my field so I will put my question in laymans vocabulary. The record grooves get 'smaller' towards the spindle while the platter has the same speed
(33 or 45). So the stylus travels shorter distance towards
the end of the record and the longer distance at the outside radius of the record. This imply different speed for the stylus and contradicts çonstant anti-skate force assumption. Or so I thought.
Regards,
|
Tony
What you have said makes perfect sense to me and my expeience. Really I don't see how you get around not having antiskate unless you drop to a very low VTF. Around 1g vtf probably needs very little antiskate. |
Nandric, I do not know for sure. Friction between the stylus and vinyl is pulling on the stylus tangential to the groove. That force is sliding friction. I do not think it is dependent upon speed- at least within a certain range. The test with a blank disc shows the same skating force at the outside and inside of the record, so I believe it is showing that the sliding friction force is constant. |
Tonywins, 'Risky business' to desagree with an engeneer but
deed you not overlook the velocity by point 2? You mentioned only the groove modulation as a cause for the anti-skate variation. In my experience only Sony made specific provision for the anti-skate variation depending
on the record radius. I assume that the engeneers by Sony
were aware of the forces involved.
Regards, |
I am an engineer. I can appreciate some of the subjective comments about anti-skate and how it affects the sound, but I want to clarify a few things here with some facts.
1) Skating force is generated by the friction of the stylus on the vinyl. This friction creates a moment (torque) on the tonearm. This moment is the distance of the friction force from the pivot point of the tonearm. This statement applies to most, but not all tonearm designs. If your cartridge is turned so that the stylus is perpendicular to the tangent of the record groove, then this statement applies.
2) Skating force is constant regardless of the tonearm position, ie. beginning or end of the record. The force can vary due to the groove modulation, but this change is a small fraction of the overall friction force. There is a youtube video demonstrating how skating force is constant with a blank disc. Excellent video.
3) Yes, the anti-skating force on the tonearm produces a moment (torque) on the cantilever, but so does the VTF (Vertical Tracking Force). Ideally, these loads should be applied directly to the stylus, but they cannot. But cartridge and Tonearm manufacturers do not design their products in isolation. So the cartridge manufacturers build a suspension system into the cantilever. This suspension system is preloaded. That means they have already built in a counter load to the VTF and anti-skating forces that will be applied by the tonearm. If you look closely at your phono cartridge while it is cued up- you might be able to see the cantilever sitting down and slightly to the right against the frame or body of the cartridge. But when cued down onto the vinyl the cantilever should be nearly centered inside that framework. At least that is what I see on my cartridge. That is why the cartridge manufacturer gives a recommended VTF range. They have built a preload into the suspension within that VTF and anti-skating force range. If you apply more or less VTF/Anti-skate, then the cantilever may not be in the optimum position.
Without anti-skate applied the left side of the groove is countering all of the skating force. This will not just possibly make the two channels sound different, but it is going to accelerate wear on one side of the stylus. So why do some phono cartridges sound better on some rigs without AS (anti-skate) applied? I'm not sure, but I speculate a couple of ideas, some of which were already mentioned. Perhaps the pivot bearing has some friction. This friction, if high enough could not just counter the skating forces but also cause the right side groove to have to move the stylus. Another possibility is that the tt is not level. Make sure your tt is perfectly level. If it is a suspended tt like mine, then you have to make sure the platter/tonearm is level, not just the base. The last possibility that I can think of why the cartridge might sound better without AS is tonearm geometry set-up. We must use our protractors to set the HTA and VTA in a static situation. That means that while the cantilever is loaded in the vertical direction (VTF) it is not loaded in the horizontal direction. That slight difference could be audible to some. Perhaps some tweaking is required to compensate. When I am setting up my tonearm position, I pull on the platter to load the stylus in the horizontal direction as I position the tonearm.
I apologize if I seem brusque. I think I am correct, but my feelings won't be hurt if someone finds an error or errors in what I have written. It is all about learning. |
Dougdeacon,
Thanks for your input. I am using an Origin Live Encounter mk2 (the dual pivot version). I am using the VPI headshell weight. I used the mint protractor to align the cart. I try to use as little VTF as possible and use antiskate to eliminate distortion in one channel. I'm not sure how many hours my Yatra has but I doubt it has 300 hours yet. I'm very happy with the this cart right now. It does have the sense of space that ZYX is known for. I just bought a Delos and I am listening to the Yatra more. To be fair I haven't set the Delos up on the new arm yet. |
Happy New Year Doug....you've clearly given this subject some thought. What, in your opinion, is the reason why turntables Nos 1-5 differ from No.6?
Cheers, |
Doug,
You're right on the money, as usual. That's precisely what I would describe: apparent benefit only to be ultimately offset by detriment to the overall sound. To answer my own question regarding why I might prefer the sound without anti-skate, I'd like to quote a post by Stringreen from a thread discussing anti-skate that I think succinctly summarized the issue:
"The force that one corrects with anti-skate is constantly changing with distance the cartridge is from the spindle, the angle of the cartridge relative to the groove, the loudness of that particular area of the record, the lightly or heavily scoring of that particular area of the record, and I'm sure other factors as well. There are those that also say that anti-skate mechanisms themselves can adversly affect tonearm performance, and that they should be disabled."
Amen. |
Moonglum, Good question: ...you will no doubt have seen cantilevers bent like a bow due to skating force Actually, I have never seen a cantilever bent/angled due to SKATING forces and I doubt anyone else has either. Skating forces pull the stylus inward. Providing that nothing resists the inward movement of the arm, no particular stress is placed on the cantilever. Everything just follows along and no deformation occurs. OTOH, I have seen cantilevers bent/angled from excessive ANTI-skating forces. If an unweighted cantilever is bent/aimed INWARD then excessive A/S or defective/sticky tonearm bearings should be investigated as possible culprits. Since these both present resistance to inward tonearm movement they may deform the suspension. (Manufacturing defects or user abuse are also possibilities of course.) If an unweighted cantilever is bent/aimed OUTWARD then a manufacturing defect or user abuse is highly likely. Skating forces, anti-skating forces or sticky tonearm bearings would not cause this. |
Dear Doug,
Thank you for your insights, your conclusions are highly plausible. At the risk of stating the obvious you will no doubt have seen cantilevers bent like a bow due to skating force (not referring to my current rig here, but past experiences BTW :)
This deformation to me suggests some stressing of the suspension. If a corrective force, albeit applied at the pivot end of the arm, renders the cantilever behaviour as straight and true as an arrow in the groove, then is it conceivable that the suspension could be LESS stressed than allowing skating force to otherwise act unhindered?
Would it be fair to say that if the cantilever looks good it is good, or is this misleading...?
Best regards... |
Dougdeacon, yes you are correct, the kW phono stage is quieter by a large margin (not even comparable) over my previous phono stage. |
SirAnthony,
It isn't VPI tonearms in particular. I hear what Harry Weisfeld hears on my TriPlanar and on a Durand Talea. Audiofeil hears similar things on five of his six tonearms.
It's partly cartridge-dependent and partly a matter of how well a cartridge/tonearm combo tracks difficult passages. The new Yatra I had on my TriPlanar for a day or two also needed a scosh of A/S. OTOH, the Airy 2, Airy 3, Atmos, multiple UNIverses, a Lyra Olympos, two Benz's and two MMs all needed no A/S after 2-300 hours of break-in. It's possible the Yatra might have reached that point too (on my tonearm) but I didn't have it around long enough to be sure.
What tonearm are you using? If it's toward the lower mass end and/or if your Yatra lacks the SB weight, that would create a borderline combo for trackability that might necessitate A/S.
|
If it's such an objectively verifiable problem, why do some (and that's Harry Weisfeld included) don't hear any improvement with anti-skate applied? It's not that we don't hear any improvement. I do. It's just that we hear many more detriments that swamp the improvement. *** The problem, as I've posted several times over the years, is that real-world A/S mechanisms apply lateral bias to the TONEARM, yet the skating force they're trying to counteract is generated at the STYLUS. Imagine, if you like, grabbing the STYLUS with your left hand and pulling it inward (skating) whilst at the same time grabbing the TONEARM with your right hand and pulling it outward (anti-skating). This is what's actually happening with skating forces vs. anti-skating mechanisms. It's easy to visualize that these unequally applied biases necessarily pressure the cantilever against the suspension. This pre-dampens its freedom to make excursions based on groove modulations. Result: softened micro-dynamics, slowed transients, dampening of the finest, lowest-level sounds in the groove. Sound familiar? This is why excessive (any) A/S sounds almost exactly like excessive VTF. Both pre-dampen the cantilever against the elastic suspension, reducing its freedom. The ideal A/S mechanism would operate like this: your left hand pulling the STYLUS inward (skating) whilst your right hand pulls the STYLUS outward with exactly the same (ever-changing) force, with zero lag time of course (anti-skating). This would avoid pre-dampening the cantilever and, if perfectly implemented, would carry no sonic penalty. Of course no one has or ever will build an A/S mechanism based on a perfectly reactive string tied to the stylus and pulling outward. ;-) The mechanisms it's actually possible to build are necessarily imperfect, as described above, and will always carry the associated sonic penalties as well as benefits. |
I don't know what VPI does that makes anti skate sound worse with it than without it, but I find it is essential. I'm sure most feel the same way. I don't need a test record to dial it in either.
I don't have a test record but I can see how torture tracks could be mis leading. I tried setting up my Yatra to an album that was cut very hot. That album sounded great but the regular albums sounded heavy and dull. Maybe some carts can track everything and sound great under any circumstances. I dont have one of those. |
I was surprised at how much my previous phono section added to the buzzing heard in bands 7-9. Nanbil, that makes perfect sense and is consistent with the observations made by Atmasphere and myself on this thread . The noise source being discussed there was record surface noise (clicks and pops) but the mechanism applies equally to the high velocity/high amplitude transients on some test records (including, most definitely, tracks 6-9 on side 1 of the HFN&RR record). Read Atmasphere's last post for a technical explanation. As your new phono stage reduced the distortion of buzzing from this stupid test record, I'd wager that it also reduced the distortion of record surface noises... right? |
A degree of anti-skate is essential.
Recordings such as soprano with piano accompaniment can be useful. The soprano is usually well centred and will produce sustained notes not dissimilar to a test tone. In this way you adjust against any "edginess" on the most intense signals.
The idea is that it should barely handle these real world signals and no more. Wholeheartedly agree with all of the above EXCEPT the first sentence, which deduces a general principle from a single example while ignoring multiple contrary examples already posted on this thread. Moonglum's rig requires A/S to eliminate edginess on the most intense signals. My rig does not (with most cartridges). Five of Audiofeil's six rigs do not but one does (with some cartridges). CONCLUSION: some rigs require A/S for clean play, some do not. Any absolute statement one way or the other is demonstrably false. I do use Moonglum's recommended recording types and listen for exactly what he described. The sound tells me how much A/S I need... if any. Doug P. S. I do not play with excessive VTF to compensate for low/zero A/S. In fact, I play my reference cartridge well below the midpoint of its recommended range, just barely above its mistracking point, exactly as Moonglum recommended. |
I didn't mean to suggest that a better phono pre-amp would fix anti-skating issues-sorry if that was the impression I left. I was just passing along my observation that the distortion produced by the tone generated on bands 6-9 were mostly caused by my phono section and not problems generated by incorrect anti-skating numbers. With the better phono section in place getting a clearer picture as to proper anti-skating values was much easier. I was surprised at how much my previous phono section added to the buzzing heard in bands 7-9. |
Actusreus,
This idea may be erroneous from the get-go, but I believe (without searching for a photo) that the VPI tonearm is one of those that has the wiring sticking up from the arm tube near the pivot. If so, it may well be that the added "force" required to move the wiring along as the cartridge traverses the LP may be just enough to serve as adequate anti-skate force with your cartridge at your chosen tracking weight. Likewise for many tonearms (e.g., Reed, Talea, Grandezza) that are similarly designed.
But make no mistake, there is a skating force generated with any pivoted tonearm where the stylus does not remain constantly tangent to the groove walls (meaning head-shell offset angle is also a factor, IMO). |
Dear Actus....For information, to get the described benefits of zero antiskate are you currently using the recommended downforce of ~1.76g with the Delos?
One practice is to maximise the downforce or even go beyond the Manufacturers recommended range to persuade the cart to track. (I've never been convinced about the need to do this, despite persuasive arguments to the contrary, but the Delos is a rare case in which downforce overload is particularly not recommended - while I acknowledge that in theory such restraint should really apply to ALL cartridges :)
Sometimes you feel downforce overload may be correcting other problems e.g. wrong SRA. However this is only my opinion.
If indeed 1.76g, are you certain there is no bias i.e. when you balance your tonearm does it remain stationary or does it sign to one side or the other?
If it does remain stationary this can also be because friction in the bearing/s can be enough to overcome any residual bias.(Noticeable with old gimballed arms)
Best regards... |
I suppose if the distortion was causing an input overload on the phono preamp, then a different preamp with a higher input tolerance would seem to fix the anti skating problem. |
Great feedback! I wholeheartedly agree with Doug and others who rely on actual music and their ears to set up their analog fronts. I guess, in the perfect world it'd be great to have your setup confirmed by objective tests, just like an amp or speaker getting a rave review in Stereophile and then measures perfectly on Atkinson's test bench, but we don't live a perfect world, do we?
As a comment to Nanbil's post, I don't quite understand how a better phono preamp should fix anti-skating issues. Skating is essentially a problem affecting the stylus' interaction with the record surface/grooves, not sound transmission. As an analogy, if your cartridge is misaligned, or wired out of phase, a better amp or a preamp should not fix the problem; in fact, it should actually make the errors more pronounced. A better preamp should only amplify the signal, not modify it.
Another thought on anti-skate is that reading the posts of those who use anti-skate, I should not prefer the sound without it, but I actually do. Music sounds more open and has more air to my ears than with any anti-skate applied. A friend of mine with a much more sophisticated equipment in his system also prefers his Classic without anti-skate. If it's such an objectively verifiable problem, why do some (and that's Harry Weisfeld included) don't hear any improvement with anti-skate applied? Does it mean our ears are not as sophisticated as others' who do? |
In a different post talking about tt speed accuracy, I was feeling ambitious one day and did some measurements and the impact of the record hole center on Wow and Flutter. My test record has about 0.8mm of eccentricity between the center hole and the center of the grooves. That resulted in a +/-2Hz variation in the 440Hz test tone on this record. The tonearm position was 3.5 inches from center. |
BTW "Band 1" means Band 6. |
A degree of anti-skate is essential.
Recordings such as soprano with piano accompaniment can be useful. The soprano is usually well centred and will produce sustained notes not dissimilar to a test tone. In this way you adjust against any "edginess" on the most intense signals.
The idea is that it should barely handle these real world signals and no more.
You may find after doing this that Band 1 just happens to sound ok also - if it doesn't sound 100% clean don't worry about it. I've had several copies of the HFN/RR and yet to find one where the spindle hole is centred with 2-3mm.
Although there are those who scorn anti-skate altogether I don't think tonearm designers add A/S mechanisms for fun.
Just my tuppence worth... |
Personally, I do both. I check my set-up with a test record but my final adjustments are done by listening. I set up my new cartridge and align it with a gage. Then I set a nominal VTF and VTA. After that, I use the stereo test record to check the set up- its really of limited use, and finally, I trim things in by ear. I set Azimuth with a mirror and use a record to check. I finalize my VTF and anti-skate using a couple of lively records and adjust my VTA for minimum noise. I hear just a little bit of mis-tracking in the right channel on my rig if I leave the anti-skating adjustment at zero when playing some records. I have to add some anti-skating. Let me also note that my TT is perfectly level. ie. the Platter/Tonearm are level since I have a suspended TT. |
LAst year , I had similar urges to check my set up with a test record.I got my panties well and truely in a bunch.Ended up ringing my dealer in desperation. His words "Bloody test discs , hate the things" . He came over , re-set things the way they had been when he originally set things up and we were both happy campers ( mind you , the bottle of vintage port helped there too).Sold the damn disc the next day.Now I use the 2 sticky out test discs I was born with like the others have said. |
As always, wise advice from Doug! |
With regard to (1), Audiofeil nailed it. Using an over-amplified test track makes no more sense than using its opposite, an ungrooved surface. Neither corresponds to real-world conditions. Adjust VTF and A/S by listening to real music.
With regard to (2), the amount of azimuth adjustment needed to equalize crosstalk is EXTREMELY small, 1 or 2 degrees at most. You want the stylus vertical in the groove to minimize vinyl wear/damage so always start from that point: make the stylus look vertical whilst playing a (real) record. Then make TINY, TINY, TINY azimuth adjustments whilst listening for the tightest imaging. When you think you've got it nailed, recheck that your stylus still looks vertical. Again, no test record required (and no mono switch either, my preamp doesn't even have one).
Train and trust your ears, leave the poorly designed tools on the shelf.
|
I found just the opposite when using the Hi-Fi test LP-it also verified that a high quality phono stage is important. When using my Denon DL-S1 through the phono stage in my Musical Fidelity A3cr pre-amp there was a just bit of audible distortion (buzzing) on band 7, with more on band 8, and again significantly more heard on band 9. Changing out the A3cr's phono section with my kW phono stage by Musical Fidelity (no other changes) resulted in no audible distortion through both bands 7 and 8 and only minimal audible distortion on band 9. When I took the anti-skate to zero (I use a Rega P7 with a Rega Rb700 tone arm) there was significantly distortion (buzzing) heard in the right channel on all three of the above named tracks. And while the Denon is able to track through track 9 with no anti-skating, I can say that there was a clear difference between the amount of distortion (buzzing) heard when various amounts anti-skate were applied. Whether or not this applies when playing music is debatable, but in my set-up, using a test record, applying a small amount anti-skate provided clearly audible benefits. |
None of the vinyl you'll play day to day have amplitude levels found on the test record.
The torture tracks are a waste of time. |
Keep in mind that the channel balance of phono cartridges is in the 1-2 dB range. So you are bound to hear something on the mono test. I think the intent is to find the minimum level which should be at the optimum geometry point. I perceive just the slightest shift in soundstage center, like maybe an inch, when playing records vs. CDs. I'm assuming it is the difference in channel balance of my cartridge and maybe even compounded just a bit by the preamp tubes. |
I use the same HIFI News 'torture test' but with the assumption that they (may) provide some indication about the stylus condition (?). To my knowledge 50 micron should be adequate for any 'normal'LP. My Phase Tech P-3G 'refuses' to
pass the 60 micron test but will pass any 'normal' LP test. The most
of my MM carts pass 80 micron test with 1,5 g VTF but there is a correlation with the anti-skate. With more anti-skate force the 'buzz' from the R.channel disappear. The logic suggest that the 'buzz' means more pressure on the 'outside' (R.channel) groove but above, say, 60 micron the question may be only academic(?).
Regards, |
|
Same experience with (1). The only arm/cart I own that would pass the HiFi News "torture tests" without buzzing is an ancient Empire 98 tonearm with no anti-skating provisions. The cart was a Stanton 881. VTF was 1.5g. |
The anti-skate bands are notoriously misleading. Everything I've read says if you get no distortion on level 6, then go no further with the test. You'll only screw things up by trying to eliminate the buzzing on the higher level tracks. |
