[anfractuosity]

I assume this is the project you mean? - https://ofersp.github.io/digital_needle/ it's a shame there doesn't seem to be sourcecode. Very cool though.

You can also get laser turntables - https://en.wikipedia.org/wiki/Laser_turntable which look intriguing

I'm rather curious about these microscopes - https://matesy.de/en/products/magnetic-field-visualization/m... which can visualise magnetic fields, they're very expensive though.

[userbinator]

If I remember correctly, laser turntables were not popular because they also reproduced all the fine dust on the surface of the disk.

[iforgotpassword]

Yep. Every tiny dust particle makes an audible pop, while an actual stylus would've just pushed it out of the groove.

[interestica]

So laser turntable needs a leading 'dust plow' ?

[morcheeba]

That sounds good! Two other solutions:

- low pass filter. Assuming the dust is small compared to the expected movement in the groove, you can filter it out electornically.

- dust detector. Nikon had a cool 35mm scanner... instead of RGB, it had an additional IR layer at an angle just to detect dust. So, automated dust removal tools knew if a black spot in an image was supposed to be there, or if it was actually dust. Here, extra optics would know if the laser was reading dust and could mute/filter the sound during that time.

[interestica]

Interesting ideas!

The 'dust detector' is 'Digtal ICE' that you'll sometimes see labeled on scanners. (https://en.wikipedia.org/wiki/Digital_ICE)

[pizza]

Someone should try doing a dsp+ml hybrid filter that takes both the optical signal and the generated audio into account to filter out the crackling