Analog Magic Question

Lewm,

Now you know of two and I can tell you from having used both, that for correcting zenith AnalogMagik is far easier to use.  The other parameter that by measurement contributes significantly is azimuth.  These two together, azimuth and zenith, contribute more distortion, and in consequence offer the greatest opportunity for improvement of all of the variables.

@lewm 

I have heard that the tool is difficult to use and/or may require sending the cartridge to Wally

The Wally zenith tool is easy to use IF you send the cart in for microscopy analysis which precisely measures zenith error as well as providing a custom shim to optimize SRA/VTA at the headshell, which is what I did.

Otherwise you are correcting by ear which I imagine isn't easy, hence Bill's comment that AnalogMagik is easier.

I have not used AnalogMagik so I am not advocating one method over the other.  

And further to that point I did not send my cartridge for microscopy analysis so my comparison is not fair either.  One other interesting observation is that using AnalogMagik I found SRA and VTA contribute comparatively little distortion.

So what does Wally or Analog Magik do to correct Zenith error? I have heard talk of a shim, in the case of Wally, but I don't see how a shim can correct zenith.  Seems to me you need to twist the cartridge with respect to the long axis of the headshell in order to bring zenith error down to zero or close to it.

Bill, when you mention azimuth, are you aiming for equal crosstalk in both channels by electronic measurement, or are you aiming for setting the stylus square or symmetrical with respect to the groove walls?

@lewm The shim isn't for zenith. You are correct, you have to change the alignment of the cart in the headshell. The "Wally Zenith" provides the correct reference point adjusted for the specific error in your cart. But as I said you have to know precisely what the error is.

There are other Wally tools for azimuth & antiskating (which also measures tonearm friction). 

Both companies have video tutorials. Check them out.

I think the main takeaway is (and perhaps @billstevenson agrees?), that conventional tools and methods will only get you in the ballpark (maybe with decent seats).

Other than truly dialed in sound, the secondary benefit for me is piece of mind. I no longer second guess the setup or feel the need to tweak it. I just enjoy it.