Hi,
The SME 3012 is another example of a 12"er that beats its 9 and 10" siblings. Not necessarily because of the reduced tracing error(that too, if set up perfectly), but because of the heavier counterweight that results in a heavier load on the knife edge bearings(reduced relative movement between knife edge and "cup" when exited by energy fed into the arms structure).
A word about tonearm geometry.
A 12" arm that has been set up with the overhang beeing 0,5mm too short(I've seen WAAYY larger misalignment at dealers and other "experts") will yield a larger max. tracing error than that of a precisely set up 9" arm.
If in doubt, it is better to have the stylus a little(no more than 0,5mm in front of your alignment grid/crosshair. This referring to an alignment gauge that adheres to Baerwald nullpoints.
The longer the arm, the more crucial it becomes to get overhang and(even more difficult to nail) offset angle spot on. For an offset angle that is a mere 0,5° too large(think misaligned cantilever), the resulting error once again will make the theoretical advantage mute.
Perfect alignment for a 12"er yields max. tracing error related distorsions of 0,45% between null points, 0,5° more causes 0,76% distorsions(compared to 0,6% for a perfectly aligned 9.4"er).
Analogous to the overhang, rather err to an angle too small. The tracing error related distorsions will then increase towards the innermost usable area only. Not too many records with modulations that close to the run out groove. Best to get it perfectly right off course...
Make sure to disengage antiskating or lower the stylus so that is just about stays clear of the template/gauge. The Antiskating will skew the cantilever, making it impossible to get zenith/offset angle right.
Recheck after cart has 100hrs on its heel.
To sum it up, spend time and use proper alignment tools or you're waisting your money on megabuck arms and carts.
Cheerio,
Frank Schröder
