setting the azimuth

eyes to closely approximate - ears to fine tune

If all carts were assembled perfectly "square" it would be a relatively easy matter, but thaty ain't ;-(

Exactly what 4yanx said, rough in by eye, fine-tune by ear.

He and I once shared ownership of a Wally Analog Shop, which adjusts azimuth by letting you measure and minimize crosstalk. It worked very well, but I found I could do just as well by listening for image tightness and separation of instruments and voices. I believe he found the same.

If you go thru turntablebasics.com they have mirror alignment protractor where you can see angle more presicely including certainly azimuth.