Gelezen op de vinyl engine (krijgen we vast en zeker geen problemen met copy right over"
Pisha: Record cleaners revisited, Audio Magazine May, 1976, p.40
Record cleaning fluids are generally mild detergents such as Alconox or a formulation containing varying strengths of alcohol. From our experience, we question the use of these types of cleaners, particularly since it has been established that contact with alcohol, Alconox, and certain anionic detergents does, in effect, oxidize the surface of the vinyl disc after a period of time. Alcohol, in almost any strength, has been identified as one of the cleaning fluids that leech out from the vinyl surface the important stabilizers and lubricants necessary for the longevity of records. Stabilizers are needed to counteract the high-heat conditions created by the stylus and for subsequent vinyl integrity, while lubricants assist in good stylus/surface contact and slippage. Unfortunately, these important chemicals are extractable from the record surface by almost any solution, but in varying degrees. By way of comparison, on a 0-100 continuum, extractions of fatty acid chains and the polyolefin groups from vinyl records by three solutions are shown in the accompanying table.
Solution, Contact time, Relative % extraction
60% Isopropanol, 10 min - 38%, 30 sec - 12%
DII fluid, 10 min - 8 %, 30 sec - 1.4 %
Distilled water, 10 min - 6.5 %, 30 sec - 0.9 %
Fortunately, the integrity of the vinyl compound is not damages to the point of making a record unplayable until the cleaning solution have been applied to the record surface over long periods of time. The process is insidious and eventually will cause damage. It appears that ANY liquid put on the surface of a vinyl record will exhibit some extraction characteristics, be it distilled water , alcohol, detergent, or the Discwasher DII solution; there just isn't a perfect record cleaner.
There is a great deal of data available on liquid record cleaners and their action on vinyl records and additional data is forthcoming from continued research in this field. At the moment, we seem to have raised more questions than answers. However, it is our intent to publish the results of these experimental findings in the near future [which apparently never happened].
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Wilson, record contamination: causes and cure, JAES 1965, p.166
"Set a record rotating at 33 rpm on a massive turntable, preferably one of considerable thickness. Then get a piece of rubber or plastic tubing a fix a metal tube in the end. Gently puff tobacco smoke through the rubber tubing and direct it (as cooled to room temperature by the metal) above the middle or thereabouts of the record. You will find that the smoke will be drawn down with a vortex-like suction towards the rotating disc, will swirl round with the disc and will then be drawn close over the edge of the turntable.
That is what happens to the air whenever a record is played : any suspended particles are irresistibly drawn down to the record surface. . At the moment, I want to call attention to the fact that this phenomenon completely explains why "pops and crackles" arise in a record mostly at the outside grooves and then at the middle of the recorded surface. Between the two there is commonly a quiet patch, as there is also nearer to the label. . The reasons are that there the vortex lines of force, as it were, change their direction; and for the material particles there will be an overshoot . particularly if the surface is statically charged.
But it is not only the larger particles of grit and dust that are affected in this way, as the smoke film shows. All fume condensates, whether smog or tobacco smoke or from household fumes - the stuff in fact that smears window panes and your car wind-screens - are pulled down with even greater effectiveness since their mass is smaller relative to the vortex forces."
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SURFACE NOSE
Factors responsible for surface noise are
1. Surface roughness : filler (tends further to chip off. leaving holes in the groove wall)
2. Welding and shearing of asperities (roughness, harshness)
3. The associated plastic deformation : microscale intermittency of plastic flow : volumetric
version of stick-slip behaviour, slipping of molecular aggregates from one position of equilibrium with their neighbours to another, discontinous motion on microscale.
4. Thermal agitation of cutting stylus
5. Lead-screw vibration transmitted to cutting head
6. Vibration of stylus induced by frictional drag, stick-slip motion during sliding friction : each
asperity (roughness) will first stick, then progressively experience elastic deformation in shear produced by the gross sliding motion, until finally the shear stress becomes high enough to produce a slip either by rupturing the asperity or by causing the adhering surfaces to separate.
Surface noise sources as mentioned under 1. - 5. are physically present in the groove, 4 and 5 are cut into the groove during cutting the master lacquer. The cartridge makes no difference between audio and such noise signals. The slip-stick motion as described under 6., however, should not be transduced into output voltage. This depends on the quality of cartridge design.
[1] Barlow : Limiting factors in gramophone reproduction, Wireless World, 1957, vol.63, p.228
[2] Hunt : On stylus wear and surface noise in phonograph playback systems, JAES, 1955, Jan., p.2
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RECORD MATERIAL
Compounds used
Main compound : Vinyl chloride vinyl acetate copolymer resin
Additives :
1. stabilizers : thermal stability, sound characteristics (noise), lubricating
2. colorant : carbon black
3. fillers : visco-elastic and sound properties (should not be used to cheapen the compound)
4. others : lubricants, modifiers, plasticizers, antistatic agents
Acetate is used to make the resin softer, acting as internal plasticizer. Used are blends of two copolymers of different molecular weight + acetate or polyvinyl chloride homopolymer + acetate copolymer. It appears that with higher percentage of acetate (which leads to higher modulus of elasticity) results in more records being warped (and consequently rejected).
[1] Khanna (RCA) : Role of polymer science in developing materials for phonograph discs, JAES 1976
[2] Khanna : Record material : Vinyl compound for the phonographic industry, JAES 1977
