Audioclinic (July 1978)

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Phono Ticks & Pops

Q. What is the reason for phonograph record "ticks" and "pops?" Is there a method for removing this noise from an already affected record?

-Steve Johnson, St. Paul, Minn.

A. Records can have "ticks" and "pops" for a number of reasons. Where the air is dry, records can build up substantial static charges, and when the voltage is high enough it jumps to ground. This spark will induce a signal in the coils of the phono cartridge, and results in a "pop" in the loudspeaker.

You can determine if this annoying sound is caused by static electricity by noting whether this sound is always present in the same passage or in different parts of the record. When it is random, you know that static discharge is responsible. The most positive remedy for this is the use of a room humidifier because the added moisture will help prevent the static charges from building up.

Another cause of "crackles" is dust particles being deposited on the surface of the disc. The cure for this problem is to keep the discs as clean as possible so that dust doesn't have a chance to be deposited on the surface.

Always use the record sleeves inserted at right angles to the opening of the jacket as this procedure aids in preventing dust from entering the sleeve.

Obtain a good cleaner from the record store and wipe each side of the disc before you play it. This will remove most of the dust particles before they become firmly lodged into the record grooves.

Try to avoid touching the grooves with your fingers. Handle the record by its edge and center only. This will prevent oil, always present on your fingers, from being deposited onto the disc, as this oil will attract and hold dust on the record surface.

Where dust has already become firmly lodged, use water under pressure to remove it, then wipe the discs with a clean, lint-free cloth. It is a tempting idea to use household detergents to make the water treatment more effective, but don't. Many of these contain perfuming agents which will attack the surface of the disc, adding more noise than was originally present. Also see the articles on cleaners by B.V. Pisha in March, 1975, and May, 1976.

Sometimes "pops" are present on a disc as the result of a production problem. A slight scratch or burr on the metal dies used to stamp out a disc can cause such a sound. An impurity in the vinyl mix can cause noise, trapped air can cause noise, and a disc pressed at too high a speed can have such noises due to lack of time for the vinyl material to fill the die properly. In these latter cases there is no remedy and replacing the disc with a new one may or may not help.

Stacking Records

Q. I recently read that it does not harm records to stack them on an automatic record changer. The article said that records have raised edges and centers so the grooves never touch. Is this true?

-Alan Cargile, Adger, Ala.

A. Examine any modern phonograph record album and note that the extreme outer edge is thicker than the remainder of the disc, with the exception of the label area. If the records are stacked on an automatic turntable, the outer edges of the adjacent discs will touch thereby keeping the grooves separated.

Early LPs were not made this way. In fact present-day 45s don't have a raised edge, but they do have raised centers and the grooves can and do come into contact with one another.

This method of thickened edges has a side benefit, less material is needed to make the disc and they are lighter and stronger than their predecessors.

If you have a problem or question on audio, write to Mr. Joseph Giovanelli, at AUDIO, 401 North Broad Street, Philadelphia, Pa. 19108. All letters are answered. Please enclose a stamped, sell-addressed envelope.

(Source: Audio magazine, July 1978; Joseph Giovanelli)

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