Record Changer - Automatic Sequencing

Automatic Sequencing

The numbering of the sides of the discs in many double and triple albums (and boxed sets of LPs and 78s) is due to their being designed to be played on record changers. After the discs were stacked and one side of each disc played, the entire stack would be turned over and replaced on the changer. Thus, to be heard in the proper sequence, the discs of a four-disc set would contain, respectively, "sides" 1 & 8, 2 & 7, 3 & 6, and 4 & 5 - a practice known as "automatic sequencing", "changer sequencing", or "auto-coupling".

The above is the "drop-automatic sequence", for record changers which drop records. These record changers do not reverse the stack as they go through them. Some other record changers, including some made in the 1930s by RCA and GE, and the Thorens TD-224, reversed the stack. The RCA and GE ones kept the stack of records on the turntable, and slid the top record to the side after playing it. A separate sequence, the "slide-automatic sequence" was made for these changers, with sides coupled 1 & 5, 2 & 6, 3 & 7, and 4 & 8.

There were also some record changers which played both sides of each record. The manual sequence works with these. Examples are the Markel 75, Capehart turnover changers, Fisher/Lincoln changers, Garrard RC-100, and Thorens Symphony CD50/CD53.

During the late 1930s and early 1940s, Victor released 78 rpm record sets in all three sequences, because they had sold players that needed all three kinds.

In the drop-automatic format, both sides of one of the records had to be played in sequence, so the whole set could not be played without any break to turn over a record, either on an autochanger or using two turntables. Some radio station copies were produced in a "relay sequence," so the records could be played by a DJ on two turntables, with no break between sides. The side couplings were 1 & 3, 2 & 4, 5 & 7, and 6 & 8. The slide-automatic sequence also allows uninterrupted play with two turntables.