Analog Magic Question

In trying to setup my SL1200GAE first with the 2M Black, the AnalogMagik software revealed that the cartridge is defective.  Wally tools did not uncover that fact.  Similarly when I setup the same TT with the VAS Nova stereo cartridge AnalogMagic disclosed a problem with arm resonance in the vertical plane, again Wally tools did not.

Thanks Bill - this makes complete sense. The same could be said for a defective tone arm wire etc. Although I would have thought a defective cart would have been disclosed by sound alone.

@billstevenson 

How did the Analog Magik software reveal the problems and defects that you noted? 

AnalogMagik is a distortion analysis program.  For example, you want to measure the amount of IM distortion in both the left and right channels at the current setting, then you want to see if changing the current setting or position can improve the numbers.  If you discover that no matter what settings you make does not result in a change in the IM distortion then you know something is wrong.  You check a different cartridge and observe that changing the position results in changes in distortion, so you know the program is working.  So you check a third cartridge and so on to confirm what is happening.  All this takes time of course.  Now you start to understand why I am seeking help by starting this thread.  And believe me, having you guys to talk about it, the back and forth is extremely helpful.  Thank you.

Most cartridges will exhibit at least some zenith error.  Parenthetically, for those who don't already know, zenith for us audiophiles refers to the angle that the stylus contact patches for left and right channel information, respectively, make with the groove wall.  Someone else quoted the industry tolerance for a +/-5 degree error, which is huge. Because of zenith error, any subsequent effort to "zero in" on the alignment of an overhung, pivoted tonearm is folly. You won't get the null points where you think they are, if indeed you get any null points at all on the playable surface of the LP. So, for me, once you've set overhang and VTA, the most important thing is to correct for the inherent zenith error built into the cartridge.  And yet, only Wally has marketed a tool to correct it, so far as I know, and I have heard that the tool is difficult to use and/or may require sending the cartridge to Wally.  But if you are finicky about alignment, you gotta face the music.

@ledoux1238 

You ask a fair question, what am I hearing?  How do I characterize the sound of distortion?  Or more specifically, when distortion is reduced, what is the result?  I am not good at describing sound.  My records sound clearer, more open.  An analogy might be drawn with photography.  It is like the difference between a well depicted image and one that is a little bit blurred.  I am still hearing that it is a Steinway backing Sarah Vaughan, but both are easier to hear.  Does that make sense?  The difference is not subtle I can tell you that.