2.1.2 Deterioration by replay

2.1.2.1 General susceptibility. With all mechanical formats, mechanical replay will to some extent cause the shape of the groove to deteriorate. Specifically, cylinders and coarse groove discs played with historic equipment have often been damaged by the high inertia and excessive tracking forces of the old replay mechanisms. In addition, inappropriate stylus shapes and materials, and poor operation of the equipment, add to the groove damage. Microgroove discs also suffer from playback using low quality and/or misaligned equipment. As a result, most of the preserved mechanical records have not retained their original groove shape and sound quality. However, carefully chosen and adjusted equipment coupled with skilled operation permits the replay of all mechanical carriers without further deterioration.⁶

Cylinders, early shellacs, and all instantaneous discs must be handed over to experienced specialists. Shellac records from around 1930 onward and microgroove discs can be transferred by skilled staff with special training.

2.1.2.2 Alignment and maintenance of equipment. Pivoted tone arms of disc players need careful alignment of the following parameters:

• Effective tone arm length to minimise the (unavoidable) tangential tracking angle (TTA) error;
• correct setting of tracking force (“stylus pressure”);
• adequate skating compensation (“anti-skate”);
• correct adjustment of the height of the arm (parallel to disc during playback), which assures the correct vertical tracking angle (VTA), (see IASATC 04, 5.2.4, 5.3.4).

For tangential tone arms, alignment is restricted to the position of the stylus, and the tracking force.

Maintenance comprises:

• Frequent, careful cleaning of the stylus.
• Occasional cleaning of the platter and the driving belt.
• Tangential tone arms: occasional cleaning of the guide rails.
• Platter bearings: occasional lubrication with acid free low viscosity oil. 

Only distilled water with mild detergent should be used for the cleaning of rubber and plastic components.

Modern cylinder replay machines must be aligned and maintained in close conformity to their manufacturer’s instructions and advice.

The keeping of log books for each piece of equipment and the careful documentation of all alignment and maintenance work is imperative.

6. Even wax cylinders will not suffer deterioration from a small number of replays by experts using good quality, modern equipment and well chosen pick-up styli. Optical replay of mechanical carriers has been explored by engineers for decades. One of the major arguments in favour —the avoidance of groove deterioration by mechanical replay—is, however, only of theoretical value. For optical replay and its potential see IASA-TC 04, 5.2.4.14.