In their time LP recordings were amazing technology. They yield excellent sound, but with some degree of surface noise. The surface noise is an inherent characteristic of the technology, sliding contact between two physical objects. It can be minimized but never completely eliminated. Minimizing surface noise requires very sophisticated procedures, machines, and materials during manufacture.
Similar difficulties exist in the manufacture of CDs, which are pressed in a manner similar to LPs. However, there is a critical difference. The information on the CD is processed using an error correcting code so that defects in the physical disc do not result in any error on playback.
A comparison of these two media is a good example of two engineering approaches to quality. One, the LP, relies on superb specs on the physical item. This is costly, and can never be perfect. The other, CDs, recognizes that physical defects will exist, and designs a system in which physical defects (up to some point) don't matter.
In my profession (engineering missile guidance systems) I saw the philosophy change over several decades. When I started our guidance systems had many selected value trim resistors and a few trim pots that were individually tweeked during tests. We tried to be perfect. Now we have few if any selected value resistors, and no trim pots. Circuit designers have learned to make circuits that do not rely on exact component values. This may result in a more complex circuit, but since you can have thousands of transistors on a tiny chip, it's a good trade off.
Similar difficulties exist in the manufacture of CDs, which are pressed in a manner similar to LPs. However, there is a critical difference. The information on the CD is processed using an error correcting code so that defects in the physical disc do not result in any error on playback.
A comparison of these two media is a good example of two engineering approaches to quality. One, the LP, relies on superb specs on the physical item. This is costly, and can never be perfect. The other, CDs, recognizes that physical defects will exist, and designs a system in which physical defects (up to some point) don't matter.
In my profession (engineering missile guidance systems) I saw the philosophy change over several decades. When I started our guidance systems had many selected value trim resistors and a few trim pots that were individually tweeked during tests. We tried to be perfect. Now we have few if any selected value resistors, and no trim pots. Circuit designers have learned to make circuits that do not rely on exact component values. This may result in a more complex circuit, but since you can have thousands of transistors on a tiny chip, it's a good trade off.