In the 6/4/01 MMD, Jeffrey Borinsky suggests using Brasso or similar
metal polish to clean the disk.
In my opinion, this is an absolutely SURE way to ruin the disk forever.
As far as I know, it is not possible to "polish" a damaged disk and
remove the noise. I strongly advise against this procedure.
[ Jeffrey was joking; Brasso might be used on music box discs
[ of metal. -- Robbie
But here is what you can do with outstanding results:
Serious audio archivists often have several phono cartridges with
different diameters and shapes of styli. This allows an unworn
portion of the groove walls to be played. This is expensive and time
consuming and required lots of experimentation.
Perhaps the most effective procedure is to use PC based recording
software. The record is played through a RIAA phono pre-amp and into
the audio board of a computer. A digital image of the disk is saved on
the hard drive. A second item of software is used to "process" the
file and remove noise, clicks etc.
I have done this regularly with both LPs and 78 RPM records. However,
for 78 RPM records the RIAA equalization is incorrect and an external
"Re-Equalizer" is required to remove the RIAA (LP) equalization and
apply the correct high-frequency and low-frequency EQ curves to the
audio. This is a hardware unit that goes in the analog audio stream
after the pre-amp and before the input to the computer audio board.
If you need more information and a source for this, please contact me
directly. The processed version of the song can now be burned to a CD
for later play. This way the original disk can be archived and not
played to death.
The software that I use is very good and is extremely cost effective.
It performs as well as professional software costing as much as 10X
more. Visit: http://www.syntrillium.com/ The recording software is
"Cool Edit 2000", price $69.00. The cleaning software plug-in is the
"Audio Cleanup Plug-In", price $49.00.
Also, it is useful to clean the disk well before playing. It's simple:
Flush the surface of the disk with plain water and pat it dry.
Better: make a very mild detergent solution and apply it to the disk
surface very lightly with a sponge. Do not rub. Try to flush the dirt
out of the grooves -- the operative word here is "flush". Rinse very
well under running water and pat dry.
Best: Use a disk cleaning machine that uses a special cleaning
solution and vacuums away the solution with the dirt in tow. They
are designed specifically for this purpose. However, they are very
expensive. If you need more information regarding a source, please
contact me directly.
Good cleaning and good listening,
John E. Lanphere
tel. 612-874-8794 evenings only please