The angle at which the stylus is inserted into the cantilever varies greatly from sample to sample of even the best made and QC'd cartridge. This can be verified using a USB microscope. Setting the arm parallel to the record surface tells you nothing about SRA. Only a microscope does. By all means let your ears be your final arbiter if you so choose but having found 87 degrees and worse on some cartridge samples with the arm parallel to the record surface means the ear method sometimes will NEVER produce correct results. You need to know your starting point SRA and parallel to the record surface is false comfort. As for cutter head angles, the survey of cutting systems done nationwide by Discwasher's Jon Rich demonstrates that 92 to 94 degrees is the average range and that it MUST be greater than 90 degrees or the cut lacquer thread cannot be vacuumed away in real time, which is a necessity because the thread is highly explosive. Rich also published Intermodulation Distortion measurements at varies SRAs proving that 92 degrees is the average 'sweet spot'. If you wish to change for every record, see a shrink. By all means recheck VTF and overhang after setting SRA if you must but don't neglect setting SRA just because it might affect those other parameters! And here I just disagree with my friend Jonathan Carr: if you raise or lower an arm 6-8mm you WILL CHANGE SRA! On a 9" arm that would change it by almost 2 degrees. On the other hand those who hear differences between record thicknesses are blowing smoke since the difference in SRA will be a fraction of a degree. And Sunnykboy you are wrong and your post is JUNK. You obviously have zero experience here. Go measure a few dozen cartridges and you'd find some measuring 84 degrees and 87 degrees with the record parallel to the record surface. Stop passing along MISINFORMATION based on ignorance.
