Grease and Static

One of the peculiarities of the plastics from which most records are made is that static electricity is easily built up in the material. The record so charged then behaves like a magnet, attracting dust, fluff and grit that may be present in the air, Grease - of which oil from the fingers is the usual source - will help to trap these particles in the microgrooves, and the scene is then set for damage to the record. It may be thought that a speck of grit that is invisible to the naked eye is scarcely likely to cause serious damage. It should be remembered, however, that the minute indentations of the groove are no more easily seen, and that the groove itself is only two thousandths of an inch wide at the top.

Seen in this light, the speck of grit in the groove may be compared with a jagged stone, the size of a tennis ball, lodged in a domestic drain! And it must be remembered that the plastic material of the record is soft. The damage is caused when the stylus, tracking the groove, collides with this grit, and drags it, perhaps to the end of the record, over the tiny hills and valleys that contain the music.

Unfortunately, the damage may not end even here: all too frequently the grit will lodge against the stylus, and will cut with similar efficiency into the track of the next record to be played.

Equipment

Obviously the quality of the original performance on any record can be reproduced only to the extent that the quality of the playing equipment will allow, and it is a sad fact that many players will so distort and deform a record on its first playing that its real potential is never realized. Even with a completely dust-free record, the pick-up must be able to follow all the indentations in the record groove if it is to reflect accurately all the sound that this groove contains. The stylus that follows this track is only one half of one-thousandth of an inch in radius, and in its passage it is subjected to violent changes of direction and speed. Unless it has almost phenomenal powers of braking and acceleration (technically called "tip mass"), and offers little resistance to the material of the track in which it moves ("stylus compliance"), the record will suffer.

If the tip mass is too great the stylus will be unable to follow the more minute modulations of the groove, and the groove itself will become deformed; if the compliance is too low the stylus will cut off corners and again deform the groove. The result, in either case, is loss of quality in reproduction. Actual notes may still be heard, but subtle overtones will vanish. No matter how light the playing weight of the pick-up, if the tip mass is too great, or the compliance too small, the groove must inevitably be deformed. The extent of the damage is only a matter of time. Groove-jumping is another effect of a defective pick-up.

Even where the jumping takes place on only one record, and on no others, it is unlikely to be the record that is at fault. Every record presents its own, unique road that the stylus must travel, and it is quite possible that a stylus will travel some of them-causing damage, but not necessarily being forced off the road-but will be utterly defeated by others. Where groove-jumping develops, resist firmly the temptation to play the record again until the trouble has been rectified; further playings will probably break down the groove wall.