HiFi News Test Record Azimuth

chakster

... only Flat Profile from the lead-in groove to the run-out groove can guarantee there is no pitch to the profile, allowing your stylus to play truly perpendicular to the grooves from edge to center ... look at the profile thickness, conventional vinyl record profile is thicker under the label area and thinner on the edge ...

That’s true only if your turntable’s platter is flat. Mine is recessed under the label area, and the LP overhangs the platter because the platter does not extend to the raised lip. A reflex clamp tightens the LP to the platter so it always lays flat. No platter mat.

@cleeds No, I think you didn’t get the point. It’s not about platter, mat or clamp or ring weight that anyone can use. It’s about vinyl record profile (you can’t change it), the so called “flat profile” is new feature of Analogue Productions and they explained very well what it is. The reference is Blue Note flat profile vinyl pressing from the ‘50s.

kunaraiker, there seems to be some confusion about what the "mirror method" is. It is extremely simple unless you are millercarbon. You are not aligning the cartridge, you are aligning the stylus. To minimize record and stylus wear the stylus (not the cartridge) has to be perfectly perpendicular to the groove. If you place a pocket mirror under the stylus, the stylus and it's reflection in the mirror form an hourglass shape. This doubles the error when the stylus is not perpendicular making it very easy to see. You can easily get the stylus within a few minutes of a perfect 90 degrees. You adjust the azimuth until the "hourglass" is perfectly symmetrical and upright. Lighting is important. Two flashlights usually works great. I use to be able to do it easily by eye only but now I find a little magnification helps. I used loops until I got a SmarTractor which has a mirrored surface and a great magnifier. 
As VTA changes azimuth will change so it helps to have a mirror the thickness of a 150 gm record.
I do not care at all about crosstalk. 

chakster

@cleeds No, I think you didn’t get the point. It’s not about platter, mat or clamp or ring weight that anyone can use. It’s about vinyl record profile (you can’t change it)

@chakster I understand your point about the LP's profile. My point is that it can still be made to lay flat by designing the platter around that profile.

Here is Chad about the history of FLAT PROFILE pressing (at 2:11 in this video). There is a JVC brochure with an example of their FLAT FACE and flat edge UHQR and conventional pressing @cleeds