I too have bought many records which appear NM, but play poorly. Just to note, most records look NM after a US cleaning (scratches excepted, obviously). Nevertheless, a well used record plays that way, no matter how it looks.
My experiments, 80KHz and 45C with an Elmasonic, would appear to contradict those claims. And in my view, experiment is the ultimate arbiter.
My experiments, 80KHz and 45C with an Elmasonic, would appear to contradict those claims. And in my view, experiment is the ultimate arbiter.