2. analog
  3. 165856-118372

Help! Antiskate with only a weight...no dial, and she's skating away!

I have a project rpm 10 carbon with 10cc evolution tonearm that has a weight on a string for antiskate. There are three notches on which to attach the string based upon the tracking force range of the cartridge. I currently have an ortofon cadenza bronze tracking at 2.5g and have the antiskate weight in the appropriate notch (according to the Pro-ject manual) from which it hangs. The table is level--checked and adjusted to ensure. The tracking force is at 2.514g (the range for the cadenza is 2.2-2.7 with 2.5 suggested by ortofon) checked with a digital scale (Riverstone Audio digital scale). The soundstage sounds great, vocals are centered, other instruments are placed in space according to the recording... Also the alignment was carefully set up using the WallyTractor and is spot on. 

But sometimes when I lower the stylus to the lead in groove, it will slide very quickly towards the spindle as though no antiskate were present (it doesn’t skip over the record, it falls into the first song groove--and yes I have confirmed that the stylus is present). But it’s a big jump vs just sliding into the groove.

So I found a blank side of an album and lowered the stylus onto the surface and it immediately slid all the way across the surface towards the spindle as though no antiskate were in play. I then disengaged the antiskate weight and experienced the same (expectedly so). But there seemed to be little or no difference between antiskate being engaged/disengaged.

So I engaged the weight again and lowered the stylus, but this time I placed a little extra force on the weight with my finger and was able to get the tonearm to stay in position--applicable antiskate force in play with this extra force. Of course, I have no way of measuring how much extra weight I applied.

The help I need:
Why is the recommended antiskate parameters set by pro-ject seemingly having no effect?
Is something else wrong?
The table and tonearm are obviously manufactured to handle this level of VTF, no?
The tonearm wires don’t appear to be impeding the arm movement.
What can I do to remedy this?
Do I need to do something to remedy this?
I wonder if I’m causing harm to the cantilever with what appears to be no antiskate, yet the music sounds great and the Analogue productions test LP record antiskate tracks "sound" equal to my ears. (But my ears aren’t young anymore, so I don’t think I can place full confidence in that audible test).

Any thoughts, suggestions would be greatly appreciated.
cabalaska

Showing 4 responses by lewm

lewm
12,537 posts
 
Mijo, my point is that most of us can’t know how much AS we’ve applied in terms of grams as a certain percentage of VTF. Even those old tonearms with numerical markings on the AS adjuster cannot be taken as units of anything. All one could say is that “5” is more than “4” unknown units of force. 
lewm
12,537 posts
 
Dear cab , it is not quite the case that “most“ of us do not think anti-skate is necessary. It seems to me that stringreen is the only one of us who consistently maintains that anti-skate is unnecessary, and he is using a VPI tonearm, which is notorious for its lack of an anti-skate device as originally conceived and for not seeming to require AS, possibly because its wiring pulls the arm wand outward enough to provide suitable AS force . After that, there are a few who are agnostic about anti-skate. But the fact remains that if you are using a conventional pivoted tonearm that places the stylus tip overhanging the spindle, inevitably there will be a skating force all across the LP. Whether that force causes audible distortion or not, for sure it is placing a stress on the cantilever and stylus that might eventually make itself known in the form of aberrant premature  stylus wear. I would add that Mijostyn is incorrect in saying that the skating force diminishes gradually as the stylus moves toward the spindle, implying that the decay is linear from outer to inner. In fact the skating force is varying all the time in a nonlinear manner and is near or at maximum at the innermost grooves, depending upon the alignment used. Furthermore, I don’t know where he got the rule that anti-skate should be equal to 10% of the VTF, if one could measure AS. I guess he is taking measurements with his invention. But none of us has access to his invention, so for any of us it would be impossible to follow that rule. However, I agree with the sentiment that one should try to use the minimum amount of anti-skate that works to produce an undistorted sound and no visible deflection of the cantilever . I would not use a grooveless  LP for anything. But you probably know all this stuff. You are wondering why your own particular antiskate device seems to be either malfunctioning or not functioning at all. From your descriptions, and your responses, I too am at a loss.
lewm
12,537 posts
 
I stand corrected. The stylus is not sliding all the way across the LP, as I first thought. Based on the second paragraph of the OP and the third paragraph, I am beginning to wonder whether there is any problem at all. I don’t think it is so unusual for the stylus to jump a few millimeters from the edge of the record into the first band on the LP. The experiment with the groove less record is possibly meaningless.
lewm
12,537 posts
 
What strikes me is that the thing is behaving in a surprising way for the problem to be just lack of any AS.  Any of us can null out his AS and play an LP; the stylus does not go skipping across the surface of the LP toward the spindle, as a result of applying zero AS. At worst, you will hear some distortion in the right channel with zero AS, but the cartridge should track OK.  So, what else could this be?  Is the internal tonearm wiring somehow putting a drag on the tonearm wand, pulling it inward?  I dunno, but something like that is what I would look for.  Step back and take a fresh look at the situation.
More to discover