"WCA"? Do we really need another acronym? What you appear to be talking about is finding the VTF (within the manufacturer's prescribed range) which will put the plane of the coil windings (basically the plane of the coil former) at a right angle to the lines of the magnetic force field generated between (or 'around', depending on the design of cartridge's magnetic generator) the magnetic pole(s). (In the case of MM cartridges, it's the reverse.)
The easiest way to determine this is to listen for or to measure (your ear will work just fine) the cartridge's maximum output at two or three nearby VTF settings (before making other adjustments.) Some tips: 1.) Do this with a mono record and (if it has one) your preamp set on 'mono'. Why? You may have harmonic distortion or minor tracking issues at this point before setting all the other parameters - but it's still important to set this one FIRST! 2.) If your cartridge is a new MC, delay all but a rough setup until after a minimum of 50 hours, AND for that first 50 hours, set the VTF to 1/4 gram OVER the manufacturer's recommended maximum. Why? First don't worry; you won't hurt the cartridge or the suspension running the VTF a bit high (and you should own an accurate digital scale by now ;-) This will result in a suspension (when break-in is over) with a 'Q' (elasticity factor) that remains constant just BEYOND the normal operating range -- otherwise, the 'Q' can be non-linear just at the point most MC cartridges yield their best output (the high end of the VTF range.)
After doing this, you can move on to setting the SRA and other alignment parameters; EXCEPT: forget VTA, which, if you give it a minute's thought, you'll realize is a totally useless concept. If everyone's cartridge's dimensions and angles (ALL of them!) happened to match EXACTLY all ALL of the cutter-head's dimensions and angles, there might be a case made -- and even then it would be philosophical at best, because you could only reliably play records made with THAT cutter-head/operator! And besides, lathe operators make adjustments too!! And cutter-heads generally are cantilever/suspension-less!
AND, if you have a stylus with a spherical or elliptical tip, you needn't worry too much because how it fits in the groove is pretty much the same over a range of SRA. A micro-ridge or line-contact stylus is just the opposite and SRA is extremely important. Here is the most accurate way to do it I've found to do it: Basically, you have to find the point (after finding/setting the optimum VTF) at which the stylus is perfectly vertical in the groove (looking from the side, not the front.) This is different for every cartridge (even among the same model/manufacturer.)
Once you've found that baseline, you can go from there. I've provided detailed instructions here: http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1140840022&openmine&zzNsgarch&4&5#Nsgarch
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The easiest way to determine this is to listen for or to measure (your ear will work just fine) the cartridge's maximum output at two or three nearby VTF settings (before making other adjustments.) Some tips: 1.) Do this with a mono record and (if it has one) your preamp set on 'mono'. Why? You may have harmonic distortion or minor tracking issues at this point before setting all the other parameters - but it's still important to set this one FIRST! 2.) If your cartridge is a new MC, delay all but a rough setup until after a minimum of 50 hours, AND for that first 50 hours, set the VTF to 1/4 gram OVER the manufacturer's recommended maximum. Why? First don't worry; you won't hurt the cartridge or the suspension running the VTF a bit high (and you should own an accurate digital scale by now ;-) This will result in a suspension (when break-in is over) with a 'Q' (elasticity factor) that remains constant just BEYOND the normal operating range -- otherwise, the 'Q' can be non-linear just at the point most MC cartridges yield their best output (the high end of the VTF range.)
After doing this, you can move on to setting the SRA and other alignment parameters; EXCEPT: forget VTA, which, if you give it a minute's thought, you'll realize is a totally useless concept. If everyone's cartridge's dimensions and angles (ALL of them!) happened to match EXACTLY all ALL of the cutter-head's dimensions and angles, there might be a case made -- and even then it would be philosophical at best, because you could only reliably play records made with THAT cutter-head/operator! And besides, lathe operators make adjustments too!! And cutter-heads generally are cantilever/suspension-less!
AND, if you have a stylus with a spherical or elliptical tip, you needn't worry too much because how it fits in the groove is pretty much the same over a range of SRA. A micro-ridge or line-contact stylus is just the opposite and SRA is extremely important. Here is the most accurate way to do it I've found to do it: Basically, you have to find the point (after finding/setting the optimum VTF) at which the stylus is perfectly vertical in the groove (looking from the side, not the front.) This is different for every cartridge (even among the same model/manufacturer.)
Once you've found that baseline, you can go from there. I've provided detailed instructions here: http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1140840022&openmine&zzNsgarch&4&5#Nsgarch
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