Here is a condensed article from April 1958, printed in "High Fidelity Specialist" magazine.
Our industry is on the threshold of one of the most significant changes in the history of music reproduction. The technical developments to reproduce stereophonic recordings on a disc have been completed, and the missing links in the chain to accomplish this are already available or soon will be. Following is an attempt to cover the questions most frequently asked concerning stereo discs. This information is of vital concern to every retailer who sells records, phonographs, component, and packaged hi-fi equipment.
1) How does a stereo cartridge differ from a conventional (monaural) cartridge?
Fundamentally, the difference lies in the ability a stereo cartridge to play back new stereophonic discs. It also has the ability to play conventional records; in fact, stereo cartridges will give superior performance on monaural records.
2) Are stereo discs compatible with conventional cartridges?
The answer depends on the type of cartridge being employed. Many cartridges now used with monaural records are satisfactory for playing stereo records monaurally. However, some cartridges are not satisfactory and will damage stereo records. To be safe, it is recommended that stereo discs be played only with a stereophonic cartridge.
3) What about playing time of a stereo LP record?
Some people have a mistaken idea that a stereo disc has only half the playing time of the conventional LP. This is not so. In virtually every case, a recording can be reproduced in stereo using the identical vinyl material of a single monaural disc. As a rule of thumb, stereo material occupies 7 to 10 percent more space on a disc. This space is made available by compressing the available material or cutting further into the center of record.
4) What effect will stereo cartridges and records have on the equipment and record market?
The ideal situation would be an orderly introduction of stereo records, cartridges, and ancillary equipment. But some discomfort must be anticipated in the market. Stereo heralds a transition which is dynamic and so great that this transition period must be endured. Once the consumer has the opportunity to hear stereo discs, he will be as enthusiastic as the retailer. Stereo on reel-to-reel tape has always been exciting, but difficult for the average consumer to handle. With the new two-channel LP, we expect stereo hi-fi will become commonplace in every household.