Copy effect

As crosstalk ( English print-through ) refers to the long-term after-effects of a magnetic with sound signals recorded and wound on a tape reel recording tape on adjacent coils. This undesirable phenomenon involves changes in the remanence of a magnetic layer due to the stray field of magnetized neighboring layers. The interference signal caused by the copy effect is called copy echo , which can be found in audio or video tapes especially after long periods of storage.

With audio tapes, an echo effect arises which, depending on the winding direction, can be heard before ("pre-echo") or after the useful signal. Video tapes give the impression of blurring, increased image noise or streaks.

The copying effect can also be used to good effect by copying from a master tape onto an unrecorded tape by direct tape contact layer against layer with simultaneous heating.

The word echo is a bit misleading here: the recording is copied onto the neighboring windings, i.e. forward and temporally like a normal echo as a delayed reproduction. The beginning of a rock music record copy can often be heard softly half a second in advance, then the copy is covered over by the loud rock music itself.

literature

• Gustav Büscher, A. Wiegemann: Little ABC of electroacoustics. 6th edition, Franzis Verlag, Munich, 1972, ISBN 3-7723-0296-3
• Patent EP 0078997 A2 - tape cassette with a recording medium with magnetic track and echo cancellation devices for such tape cassettes , registered on October 28, 1982