VPI uses a proprietary, single null-point-jig to align the carts on the JMW series arms. I say 'proprietary' since HW has seemed unwilling to release any specifics on how it came to be, though I believe it's meant to skew the inevitable tracking compromise towards lower distortion on the inner grooves.
My experience has been that an arc protractor will provide more satisfying results, but at any rate, you need to learn how to mount a cartridge, for at least two reasons:
*Unless you have a dealer who will come to your home, and mount and adjust the cart on the turntable where it will be permanently situated, and said dealer has a long and revered reputation for doing exacting work, you're (much) better off doing it yourself.
*You shouldn't be going a year without checking your cart adjustment
My experience has been that an arc protractor will provide more satisfying results, but at any rate, you need to learn how to mount a cartridge, for at least two reasons:
*Unless you have a dealer who will come to your home, and mount and adjust the cart on the turntable where it will be permanently situated, and said dealer has a long and revered reputation for doing exacting work, you're (much) better off doing it yourself.
*You shouldn't be going a year without checking your cart adjustment