Rega RB300 Anti-skating problem


I have a Rega RB300 tonearm and a Grado Master Reference cartridge ,
currently the VTF is 1.6 grams and the anti-skating is set to zero .
When using Cardas records that have blank tracks the tone arm wants to move to the outer edge of the track .
This is with the anti-skating is set to zero ! if I set it to anything above it moves outward even faster .
The only way I can have the cartridge not move on the blank tracks is to set the VTF to at least 2 grams .
Checked tt ( Merrill Heirloom ) level , Checked plater level ,
the only thing I can think of is the anti-skate magnet is not working as intended ( the tonearm was re-wired ) .
Any thoughts or suggestions ?
Thanks

128x128vair68robert

Showing 1 response by millercarbon

First of all the blank disk trick is hardly the way to set anti-skate. The only value to it here that I can see is its telling you that in spite of being set at zero your arm is in fact giving some anti-skate. How much is the question. But it is not zero.

But you do not want zero anyway. How much you do want varies depending on not just VTF but groove modulation. More highly modulated grooves cause more stylus drag which requires more anti-skate. This is why the blank disk trick is baloney. Don’t take my word for it go track down Mikey Fremer who talks about this, you just have to listen to an hour long video to find the fifteen seconds he spends on this. Or trust me. Or heck even just think about it. Your call.

Now what this means is if your anti-skate is set correctly for music that is going to be too much for a blank and the arm will move outward- exactly like yours is doing. But not by much, which you confirmed by only needing to increase VTF very slightly. So what you have really done is demonstrated that regardless of how the arm is calibrated it is in fact providing just about the right amount of anti-skate. And yeah it would be nice if it was doing this at something like 1.6 instead of zero. That is really all we are talking about here.

The correct way to set VTF is first get it within spec and then fine tune by ear. The last thing you would ever do is run VTF that is both too high by spec and sounds bad by ear just because the VTF marks or whatever on your arm aren’t calibrated accurately.

Keep in mind a lot of people including arm makers question the importance or value of anti-skate at all. I’m not taking sides or anything merely trying to put this in perspective. To contrast anti-skate, which it is at least reasonable to question, with VTF, which for very real reasons of design and function needs to be within the manufacturers specified range. Not to mention the way it sounds when its too high. Which you clearly noticed. When you haven't said anything about hearing anything actually related to anti-skating. Perspective.

Also not saying its not worth trying to figure out why your arm is showing zero when it is in fact giving some amount of anti-skate. All I’m really saying is if everything you’re saying is true then you really don’t need to do a darn thing except go back to where you were only now knowing that doing the blank disc test without first understanding what its all about is more trouble than its worth.