Pickup SRA - starting from a 500x microscope

One problem I can think of with using the trusted ear method of determining the proper angle, any of the angles involved, is that you never know when you have achieved a local minimum, in terms of distortion. That is why a technical method should yield better results. Analogous to trying to determine the ideal best sounding speaker locations by ear. Technical solutions should yield better results than ye olde move a little, listen a little method.

SMoffat - You can use Pixelstix for both horizontal and angle calculation. Sorry I should have mentioned this sooner is another good 'horizontal' calculation program is Go Horizontal. Its costs less than $5 too and is even more simple to use.

I would go with Go Horizontal for the 180, and then ImageJ for the angle calculation. Pixelstix combines both but is more complicated to use.

Something to keep in mind is that all LPs are different- so the 92 degree SRA should be considered an approximation.

The simple fact of the matter is that the cutting stylus only lasts about 10 hours before replacement is required to continue doing low noise cuts on the lacquer. To replace the stylus, the cutting engineer has to remove the cutterhead from the lathe to do the job. Once done, it is then a matter of re-installing the cutterhead and getting it to work right again. That involves a number of test cuts until a number of the variables are worked out. These include stylus temperature, cutting angle, cutting depth and pressure (similar to tracking pressure, but cutting instead and somewhere between 60 and 70 grams is typical on our cutterhead).

The simple fact is that while you have to have a certain rake angle, in practice it might be 92 degrees and it might not. What it is will be whatever was required to get the cutterhead to cut a groove properly. As a result, all LPs are slightly different; 92 degrees is a good average.

Interesting that the OP is trying to figure out a method for setting the correct 92deg SRA on an Atlas yet the venerable Mr Carr at Lyra ( for whom I have the highest respect and admiration) is not a great fan of SRA.
A bemused Atlas owner !

Thanks for advice! I dislike it, however, when an honest question is turned into a stupid statement. Rpeluso writes as if I've left my ears behind - I have not. Going the visual way is a "nightmare". Well perhaps not though I trust my ears mainly. And Sunnyboy1956, where has Lyra said that SRA/VTA plays no role? It is more that they try to adjust for some margin, in my interpretation - but J Carr would be welcome to speak for himself. "Not a great fan" - who is? Karl Marx talked about the world of neccessity. Few audiophiles "want" to go into this SRA microscope testing business. The reason they do it, is to get the best possible sound from their pickups. Same with me.