[sdiy] Fw: [NM] Very special question about "harmonics"

[nN AAt e e]

I'm forwarding this from the Nord Modular list, as it looks slightly out of
the range of the modular, but an interesting and possibly quite simple in
todays modern age of super digital electronics [DIY ones of course]
- nate

----- Original Message ----- 
From: <lesgammas at freenet.de>
Subject: [NM] Very special question about "harmonics"


SInce I´m working as a vinyl cutter (single "dubplate" items at the moment
but I´m looking for a possibility to cut vinyl masters as well...), I found
a very interesting topic about cutting head distortion on a VERY GOOD
website (for those who are interested:
www.sickoftalk.com/whyvinyl_two.html ).
My concern is to reduce the feedback produced by the cutting stylus in the
laquer material. To keep it short, I´d like to use the audio inputs of my
micro to create exactly what a not-to-find Neumann piece from the 70s did:
maybe one of you has the skills to give me some hints (or even a
schematic/diagram) for how to patch such a module.
So, here´s the task:

"A more effective means of reducing tracing, pinch effect and groove
excursion limit distortion is through the use of a "tracing simulator" such
as Neumann's Model TS-66. All three of the discussed types of distortion are
predominately of the second harmonic variety. Pre-distorting the signal to
be cut on the disc in an inverse manner to the distortion generated by the
playback stylus (Fig.12-19) can reduce their effect. The tracing simulator
generates a voltage corresponding to the second harmonic of the program
signal and adds it to the program out of phase with the distortion created
in playback. This second harmonic component is cancelled by the tracing,
pinch effect, and groove excursion limit generated during playback,
resulting in a disc with substantially less distortion and greater high
frequency level capability. "

Thanks in advance, best wishes to you all,
MARC
--