[kurthr]

You're joking, but based on the dynamic range (claimed by audiophiles) over a min length of ~160um (more on the outside less interior for 2kHz tone) and the peak motion ~37um per channel.

PVC grains are typically 100s of um in size, but the monomers themselves are ~10nm. Note that with 120dB claimed dynamic range this would be 37nm of deflection (at 45deg or 25nm lateral) for full resolution. That is close (3x off) to molecular Atomic Force Microscopy.

Of course what is encoded is actually force/velocity which in turn is inductively coupled out, but it is no surprise that simple optical scanning gives you mediocre results. Even 10x lower dynamic range requires 250nm optical resolution. It's doable, but not easy.

[ByThyGrace]

Thanks for the informative explanation! If say an 12-inch LP is scanned at 250nm optical resolution, what output digital image resolution are we talking here (in pixels)?

[kurthr]

It would be truly terrifying resolution. Just a 4"x4" area at 10um resolution would be 10k resolution.

Here's a good place to look for vinyl LP info:

http://www.gzvinyl.com/About-vinyl.aspx