Loop bin duplicator

A loop bin duplicator is a specialized audio tape machine utilized in the duplication of pre-recorded audio cassettes. It uses a long loop of 1/2" wide tape loaded in a large bin located in the front of the machine, which is read by the duplicator at a very high speed, either 32 or 64 times (60 and 120 ips respectively) the normal speed of playback of an audio cassette.

While this loop is being played back, it is recorded to a reel of raw 1/8" audio tape wound on a "pancake" reel (similiar to motion picture film wound on a plastic core) at the same high speed. After it is recorded, this pancake of tape is then loaded onto special machines called loaders. The loader has empty cassette shells with no tape loaded in them (called a C-0 cassette), save for a leader. The tape from the pancake is then spliced onto the C-0 cassette's leader and then wound into the cassette.

The 1/2" loop of tape in the duplicator usually will have a segment of clear leader spliced in between the beginning and end of the program. This clear leader splice is read by a optical sensor in the loop bin duplicator, which triggers a cue tone recorded to the reel of 1/8" pancake tape. This cue tone tells the loader to stop and cut the tape from the pancake and splice to the other strip of leader in the cassette shell. In fact, part of this tone can be heard at the leader splice of some pre-recorded audio cassettes, as a very low-frequency rumbling, but as an actual tone when played back at a higher speed.

In the XDR duplication process, the loop bin duplicators use 1" loop tape instead, yielding in a better quality duplication.