The Secret Society of Lathe Trolls

Could it bei something completely different than polishing? Maybe air bubbles during electroplating?
Kind regards

But somehow I cannot imagine that polishing a stamper or any other mecanical abuse of the stamper would cause these strange artefacts to the groove bottom.

Bernd

But why would someone want to polish the stamper? That makes no kind of sense from my perspective. I only know mothers beeing polished (dehorning).
Bernd

The grooves are not as deep that I would think about a cut into the aluminium disc. Actually i would guess that the master was cut with an advance Ball and without variable depth. The sound is a sort of crackling in the loud passages.

Dear plating and pressung specialists, did anyone come across such an plating/pressing error? I found it on an old stereo lp from 1959 and i made a microscopic Investigation, since that error is very obvious in the sound. Has anyone an Idea what caused that deformation of the groove bottom? Kind reg...

Dear friends,
is there anyone who can send me the schematic diagram of the Neumann feedback amplifier GV2?
Kind regards,
Bernd

Thank you, Mark. You should have a PM now. I already tried it, but obviously I failed ...
Thanks a lot!!!

Hello everybody! No, I think the PDF is a conference paper from 1958 and not this one from 1959, which I would like to have: A New Stereo Feedback Cutterhead System R Narma, NJ Anderson - Journal of the Audio Engineering Society, 1959, Volume 7 Issue 4 pp. 153-159 It should be this one, I think: htt...

Thank you a lot, Mark. You got a PM. I am very curious how the Narma design works in detail. We are going to evaluate and test several different dransducer systems including finite element method to get more detailed information about the systems rigidity and so on. I am looking forward to your emai...

Hello to everybody, is there anyone who could help me by sending me a PDF or a scan of this publication? Unfortunately we don't have this journal in the university library. Greetings to all! (Einen schönen guten Abend an alle! Gibt es in diesem Forum jemanden, der mir mit einem Scan oder einem PDF v...