Re: [AV Media Matters] Transcript Discs

[Matthew_Davies@screensound.gov.au]

Sometimes I think these terminology things are just great examples of
subtle difference in language, Bob, one of the interesting facets of our
easy access to a global discussion group.

The big risks with any sort of coated disc are related to the coating's
softness and solubility. A mentor of mine once admitted he had completely
destroyed a lacquer disc by cleaning it in a mild alcohol solution intended
for cleaning pressings, not a mistake he'll make twice (and I guess my
chances to make such mistakes are pretty slim now I work mostly in the
office). Gelatine coated discs are even more vulnerable.

For the record, heres a few points on our standard practice at ScreenSound
Australia :-

Discs without any lifting or cracking can be wet cleaned. Our best cleaning
solution is 1% cetrimide in de-ionised water, use very mild solvents such
as eucalyptus oil to remove spots of heavy contamination - test the solvent
in the run out area first.

Discs with loose pieces or cracks in the lacquer should be dry cleaned,
soft brush etc. I used to use Freon TF to clean these discs, now banned in
Australia but did a great job.

High compliance stylii cause less wear on the soft groove wall, and should
be used unless the disc has cracks or missing pieces. In this case a low
compliance stylus is useful for better tracking across any discontinuities.

Stylii selection - our preferred stylii for lacquers are the Stanton
bi-pointed stylii intended for playing stampers and other negative discs.
D6915BPSR through D6950BPSR (low compliance) or D6915BPSM through
D6950BPSM. The unusual profile of these can minimise the effect of previous
wear and damage, as the stylii tends to track in a less worn part of the
groove if you get the size right.

Equalisation is ussually flat in the top end, with a turnover at either 250
or 500 Hz at the bottom.

As an aside, I believe that at least some of the recorded UN speeches by
Australian delegate H V Evatt were produced in a small run of disc
pressings. I don't know if this would have been common practice. Cheers.
/MD