SRA/VTA adjustment requires overhang adjustment. This point has been mentioned by some and glossed over by others. Here is Judith Spotheim's take from her setup instructions at page 20 for her 1990's The SpJ Arm (which allows for VTA & overhang adjustment by micrometers):
"Certain audible improvements achieved by adjusting VTA without compensatory adjustment of overhang are actually nothing more than the manipulation of the stylus tip location into the vicinity of a more accurate overhang setting. To properly adjust VTA away from the reference point, it is necessary to also adjust the overhang..."
"Adjusting for the discrepancy in the overhang brought by VTA alteration of 2.5 degrees (with an effective length of 244 mm) requires moving the arm's pivot point 1 mm forward....(An error of 2mm in overhang can increase tracking error distortion by 300%!)"
"Certain audible improvements achieved by adjusting VTA without compensatory adjustment of overhang are actually nothing more than the manipulation of the stylus tip location into the vicinity of a more accurate overhang setting. To properly adjust VTA away from the reference point, it is necessary to also adjust the overhang..."
"Adjusting for the discrepancy in the overhang brought by VTA alteration of 2.5 degrees (with an effective length of 244 mm) requires moving the arm's pivot point 1 mm forward....(An error of 2mm in overhang can increase tracking error distortion by 300%!)"