Dels blogs: Cleaning the vinyl

Transcric sense traduir els dos comentaris que el blog de música folk Time Has Told Me ha rebut en un post en què un dels seus membres escrivia que havia començat a digitalitzar la seva col·lecció de vinils i demanava consells sobre software per netejar el so o ensenyaments per arranjar correctament les cobertes dels discs. La informació és detalladíssima.

"When recording (or just playing) vinyl, I always have the surface of the record wet. A drop or two of liquid detergent in 500ml of water is usually sufficient dilution. Keep it in a plastic bottle next to your turntable, put a few drops on the record and smear it across the surface. Any static electricity will be completely eliminated and other surface clicks will often be significantly reduced. If the record is very dirty, the solution will soften the dirt, causing it to build up on the needle (stylus). Clean the needle and try a second time if necessary".

"We clean all LP's before ripping them with denatured (distilled) water and a few drops of detergent. We use a lint free cloth (this is important). Using toilet tissue or tissues from a box will leave more micro-filaments on the record surface than dirt it removes. The surface is washed with the lint free cloth in a circular motion following the grooves. When both sides have been really cleaned, the surface is washed off with plenty of denatured water and a small addition of alcohol (Isopropol), not more than 5% of the water volume. This helps evaporation.
Finally we spin the LP at 1800 RPM (yes 1800) clamped to the spindle of an old industrial fan motor with a specially made spindle clamp.
Its worth remembering that this could be a dangerous operation, never stand and watch it!! We've not had an LP explode YET, but take no chances.
This is better than pure air drying, which always leaves some smears on the surface.
Wet playing is NOT reccommended for quality copies.
Recording the LP requires the best turntable and arm/cartridge combination you can find. You need a really good phono amplifier with low hum before you even start to try to digitise it.
Digitising can be done with a good sound card that allows line input connections to be made to the phono amplifier. If your sound card supports 20 or 24 bit, use it, this will make subsequent de-clicking much easier. We work exclusively at 24 bits right up until the actual MP3 conversion.
We use an Edirol R09 digital recorder here, this provides a 24 bit wave file on an SD card which can be read straight into the PC digitally for editing.
Surface noise removal is by Cool edit (or Adobe audition) using a noise print from the lead-in of the LP (or inter track gap). Sound Forge, is used to re-draw out the major clicks.
Setting recording levels:
Important: Always play the LP first and set the sound (record) level so that it NEVER exceeds the -6dB mark on the VU, you can always raise a low recording digitally later, but once you overload a recording is ruined for ever. This is specially important as clicks will often be a lot louder than the peak music, if the click is clipped by overload it will be made longer and more noticable, also be harder to correctly draw out (remove).
Good luck..."