the reason i ask is usually arms are supposed to be parellel with the record - for an ab id need a 5mm mat - which sounds bad - even 4mm is not good - ive settled at 3mm arm slightly downhill - thoughts?
At one time it was considered important to get the vertical tracking angle (VTA) "right", and some tonearms even had VTA adjustable on-the-fly. Simple point contact styli with conical or elliptical shapes are fairly immune to small change in VTA but fancier line-contact shapes perform better if lined up matching the mastering cutting.
Only problem is that the original cutting angle wasn't universal; it was chosen to make the shavings peel well, and different folk had different ideas about shavings. At one time 15 degrees was the magic number, later it was 20. In general, the current situation, with recordings from these many decades of various engraved VTA, is to make the top of the cartridge body parallel to the record surface. You don't know the angle of your stylus anyway, because you can't measure it.
All good fortune,
Chris
Only problem is that the original cutting angle wasn't universal; it was chosen to make the shavings peel well, and different folk had different ideas about shavings. At one time 15 degrees was the magic number, later it was 20. In general, the current situation, with recordings from these many decades of various engraved VTA, is to make the top of the cartridge body parallel to the record surface. You don't know the angle of your stylus anyway, because you can't measure it.
All good fortune,
Chris