Explanation of Side Coupling for 78rpm Sets

Many of the 78rpm sets listed in this Discography, particularly the electrical sets, were issued in up to three side couplings, described here as:

  • Manual side couplings
  • Slide automatic side couplings
  • Drop automatic side couplings

For an example, see the 1926 Mikado.

In a hypothetical set comprising four records, the alignment of the sides would have been:

  • Manual: 1/2, 3/4, 5/6, 7/8
  • Slide Automatic: 1/5, 2/6, 3/7, 4/8
  • Drop Automatic: 1/8, 2/7, 3/6, 4/5

The difference is shown pictorially in this diagram [193K] scanned from the RCA Victor Musical Masterpieces Catalogue of 1940, which Bruce Miller provided.

Manual side couplings came first. To play the records, the user simply played each side one after the other — side one, then side two. Each side lasted only four to six minutes, so the listener had to reload the player frequently. Of course, this arrangement wasn't called "manual" until automatic couplings arrived.

The Victor Company introduced the first mass-market slide automatic players in 1927. At the time, they were called just "automatic" (the modifier "slide" being unnecessary, since there was only one kind), while the original style was referred to as "straight." Here is an explanation of how the original automatic system worked, from Robert W. Baumbach's Look for the Dog (Stationery X-Press, 1981):

Because of the bulky record changer mechanism, this machine was housed in a huge (by previous standards) cabinet. At nearly five feet wide, this front-loading Victrola was quite unlike anything previously made in Camden [Victor's headquarters] and dominated the average living room....

In retrospect, the operation of Victor's first record changer seems odd and unnecessarily complicated, but it must be remembered that in 1927 it was unique — there simply was no standard to follow. For example, it was known that for the optimum needle-to-record angle to be maintained, only one record could be permitted on the turntable at any given time. This, of course, required that each record be removed from the turntable after it had been played — a luxury of design seldom found in modern record changers. Many subsequent record changer designs followed the guidelines set by this first Victor product, until the Depression economy forced a simplification of the requirements and adaptation of the cheaper drop-type designs in the middle thirties.

To play a program of recordings on one of the new automatic Victors, one assembled as many as a dozen 10-inch or 12-inch records (but not intermixed) into one of the new style partitionless record albums provided with the instrument. A special "Record Loader" was slipped through the center hole of each record and lifted to the overhead spindle which held the selections prior to their use. As a ring surrounding the turntable was brought upwards to meet the bottommost record on the spindle, it automatically deposited the last record played into a drawer in the lower part of the cabinet. In this way, the only record on the turntable was the one being played. At the conclusion of the program, the entire stack was removed from the drawer and returned either to the spindle (upside down, in order to hear the flip sides) or to the record album.

If the operation sounds clumsy, it was, but it did have one redeeming feature: it worked!.... Victor introduced a redesigned changer mechanism in the fall of 1928. The new design had the advantage of accepting 10-inch and 12-inch records intermixed and took up considerably less room in the cabinet. It held the program of up to twelve records in a tray rather than on a spindle, and was thus easier to load than its predecessor (and could be loaded while playing). A repeat control was added, allowing the owner to hear his favorite records again and again. The finished record was ejected simply by lifting it at the rear and allowing the clockwise rotation of the turntable literally to fling it to the left and into a receptacle. This technique was not as gentle as the older, more complicated system and occasionally record damage was known to occur.

After the start of the depression, automatic players were seen as an unnecessary luxury. Indeed, for a while the survival of the entire recorded music industry seemed in question. Towards the end of the depression, the far simpler "drop automatic" system was introduced. This sytem will be familiar to most readers, as all of the D'Oyly Carte LP sets were issued this way. Instead of flinging records to the side, drop automatic players simply dropped the next disc on top of the previous one, a system that was not only mechanically simpler, but also less likely to damage the discs. Some early drop systems had a mechanism to lift the tone arm, to maintain the proper playing angle, but most of the LP players that came along later dispensed with this.

Once drop automatic machines took off, slide automatic seems to have disappeared relatively quickly. Manual side couplings never completely went out of fashion, however. Through the end of the 78rpm era, and even through part of the LP era, many consumers bought their sets one disc at a time. Obviously, a buyer would be far more interested in buying sides 1 & 2 than sides 1 & 22.

In addition, some people claimed that dropping discs — albeit only a distance of a few inches — damaged the grooves, even though actual breakage was unlikely. Consequently, except for opera, many publishers of multi-disc sets stuck with the manual format. Of course, by the time LPs came out, buyers generally did not get the choice of what format they preferred.