Cartridge manufacturing inaccuracies are the main source of azimuth and SRA errors.
In my experience, many "boutique" cartridge manufacturers do not have either the equipment or the set of procedures needed for consistent quality control. Even the hand-picked samples given to magazine reviewers sometimes have SRA and azimuth quite far away from what a consumer can reasonably expect.
In the next installment, we will explore the dynamic geometric errors resulting from stylus tracing the groove and following the disc's imperfections. Korf team is visiting High End 2017 in Munich
, so the next blog post will be delayed by a week.